Detection circuit for PCBA board

Abstract

The utility model discloses a detection circuit for a PCBA board, and the circuit comprises a control module which is used for controlling the output voltage of a power module; the power supply module comprises a first conversion circuit, a second conversion circuit and a power measurement circuit; the first conversion circuit is connected with the control module and outputs a power supply to supply power to the control module; the second conversion circuit is connected with the power detection circuit; the second conversion circuit outputs a power supply to supply power to the power detection circuit; the power detection circuit is respectively connected with the control module and the PCBA board to be detected, and the power detection circuit is used for detecting whether the power of the PCBA board to be detected is normal or not. According to the utility model, the circuits are combined to form a circuit which can test whether the power of the PCBA board is normal or not, so that the performance and the safety of the PCBA board to be tested are judged, and potential electrical problems are avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of detection circuit field, specifically a kind of detection circuit field for PCBA board. BACKGROUND

[0002] PCBA is the abbreviation of Printed Circuit Board Assembly, i.e. printed circuit board assembly. It is welded to circuit board by SMT patch, DIP plug-in process, etc. electronic components, forming complete electronic product. PCBA board is the core component of electronic product, and its performance directly determines the function and reliability of the whole product.

[0003] In the design or production process of PCBA, due to design unqualified or production process problems, etc. internal circuit failure occurs. These problems can be detected in time to ensure product quality.

[0004] Traditional PCBA board test mainly tests its internal on-off, and whether the welding point is loose, etc. It does not test its power, cannot ensure the performance and safety of the product, and cannot avoid potential electrical problems, etc. UTILITY MODEL CONTENTS

[0005] In order to overcome the above technical defects, the utility model provides a kind of detection circuit for PCBA board.

[0006] In order to solve the above problems, the utility model is realized according to the following technical scheme:

[0007] The utility model discloses a kind of detection circuit for PCBA board, including control module, the control module is used to control the output voltage of power module;Power module, the power module includes first conversion circuit, second conversion circuit and power measurement circuit;The first conversion circuit is connected with the control module, and the first conversion circuit exports power supply to the control module power supply;The second conversion circuit is connected with the power measurement circuit, and the second conversion circuit exports power supply to the power measurement circuit power supply;The power measurement circuit is connected with the control module and the PCBA board to be measured respectively, and the power measurement circuit is used to whether the power of PCBA board to be measured is normal.

[0008] Further, the control module includes single-chip microcomputer, first resistor, second resistor, third resistor, fourth resistor, fifth resistor, sixth resistor, seventh resistor, eighth resistor, ninth resistor, first capacitor, second capacitor, third capacitor, fourth capacitor, fifth capacitor, sixth capacitor, seventh capacitor, eighth capacitor, ninth capacitor, tenth capacitor, active crystal oscillator, key, first static protection diode, second static protection diode, three-hole terminal and four-hole terminal;

[0009] The VDD_1 pin of the single-chip microcomputer, the VDDA pin of the single-chip microcomputer, the VDD_2 pin of the single-chip microcomputer and the VDD_3 pin of the single-chip microcomputer are connected to a power supply;

[0010] The VSSA pin of the single-chip microcomputer, the VSS_1 pin of the single-chip microcomputer and the VSS_2 pin of the single-chip microcomputer are grounded;

[0011] One side of the first resistor is connected to the PF7 pin of the single-chip microcomputer, and the other side of the first resistor is connected to a power supply;

[0012] One side of the second resistor is connected to the PF6 pin of the single-chip microcomputer, and the other side of the second resistor is grounded;

[0013] One side of the third resistor is connected to the BOOT0 pin of the single-chip microcomputer, and the other side of the third resistor is connected to ground;

[0014] One side of the fourth resistor is connected to the X2 pin of the active crystal oscillator and the PF0 pin of the single-chip microcomputer respectively, and the other side of the fourth resistor is connected to the X1 pin of the active crystal oscillator and the PF1 pin of the single-chip microcomputer;

[0015] One side of the first capacitor is connected to the X1 pin of the active crystal oscillator, the other side of the first capacitor is connected to the GND2 pin of the active crystal oscillator, and is connected to ground;

[0016] One side of the second capacitor is connected to the X2 pin of the active crystal oscillator, the other side of the second capacitor is connected to the GND1 pin of the active crystal oscillator, and is connected to ground;

[0017] The third pin of the key is connected to the NRST pin of the single-chip microcomputer, and the fourth pin of the key is connected to ground;

[0018] One side of the third capacitor is connected to the NRST pin of the single-chip microcomputer, and the other side of the third capacitor is connected to ground;

[0019] One side of the fifth resistor is connected to the NRST pin of the single-chip microcomputer, and the other side of the fifth resistor is connected to a power supply;

[0020] One side of the sixth resistor is connected to the PB10 pin of the single-chip microcomputer, and the other side of the sixth resistor is connected to the third pin of the three-hole terminal;

[0021] One side of the seventh resistor is connected to the PB11 pin of the single-chip microcomputer, and the other side of the seventh resistor is connected to the second pin of the three-hole terminal;

[0022] One side of the first electrostatic protection diode is connected to the second port of the three-hole terminal, the other side of the first electrostatic protection diode is connected to the first pin of the three-hole terminal, and the ground;

[0023] One side of the second electrostatic protection diode is connected to the third port of the three-hole terminal, and the other side of the second electrostatic protection diode is grounded;

[0024] One side of the eighth resistor is connected to the PB10 pin of the single-chip microcomputer, one side of the ninth resistor is connected to the PB11 pin of the single-chip microcomputer, and the first port of the three-hole terminal is connected to the ground;

[0025] The second port of the four-hole terminal is connected to the SWCLK pin of the single-chip microcomputer, the fourth pin of the four-hole terminal is connected to the SWDIO pin of the single-chip microcomputer, and the third port of the four-hole terminal is connected to the ground;

[0026] One side of the fourth capacitor is connected to the ground, and the other side of the fourth capacitor is connected to the first port of the four-hole terminal and the power supply;

[0027] The fifth capacitor, the sixth capacitor, the seventh capacitor, the eighth capacitor, the ninth capacitor and the tenth capacitor are connected in parallel, one side of the fifth capacitor is connected to the power supply, and one side of the tenth capacitor is connected to the ground.

[0028] Further, the first conversion circuit outputs voltage in a step-down manner;

[0029] The second conversion circuit outputs voltage in a step-down manner.

[0030] Still further, the first conversion circuit includes a tenth resistor, an eleventh resistor, a twelfth resistor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a first core inductor and a first DC-DC converter;

[0031] One side of the tenth resistor is connected to the VIN pin of the first DC-DC converter, and the other side of the tenth resistor is connected to the EN pin of the first DC-DC converter;

[0032] One side of the eleventh resistor is connected to the FB / OUT pin of the first DC-DC converter, the other side of the eleventh resistor is connected to one side of the first core inductor, and the other side of the first core inductor is connected to the LX pin of the first DC-DC converter;

[0033] One side of the twelfth resistor is connected to the FB / OUT pin of the first DC-DC converter, and the other side of the twelfth resistor is connected to the ground;

[0034] One side of the eleventh capacitor is connected to the VIN pin of the first DC-DC converter, and the other side of the eleventh capacitor is connected to the ground;

[0035] One side of the twelfth capacitor is connected to the VIN pin of the first DC-DC converter, and the other side of the twelfth capacitor is connected to the ground;

[0036] One side of the thirteenth capacitor is connected to the BS pin of the first DC-DC converter, and the other side of the thirteenth capacitor is connected to the LX pin of the first DC-DC converter;

[0037] One side of the fourteenth capacitor is connected to one side of the first iron core inductor, the fourteenth capacitor is connected to the FB / OUT pin of the first DC-DC converter, and the GND pin of the first DC-DC converter is connected to the ground;

[0038] The first electrolytic capacitor, the fifteenth capacitor, the sixteenth capacitor, the seventeenth capacitor and the eighteenth capacitor are connected in parallel, the positive electrode of the first electrolytic capacitor is connected to one side of the fourteenth capacitor, one side of the eighteenth capacitor is connected to the positive electrode of the first electrolytic capacitor, and the other side of the eighteenth capacitor is connected to the ground.

[0039] Furthermore, the second conversion circuit includes a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a nineteenth capacitor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a twenty-sixth capacitor, a second iron core inductor, a second electrolytic capacitor, and a second DC-DC converter;

[0040] One side of the thirteenth resistor is connected to the VIN pin of the second DC-DC converter, and the other side of the thirteenth resistor is connected to the EN pin of the second DC-DC converter;

[0041] One side of the fourteenth resistor is connected to the FB / OUT pin of the second DC-DC converter, the other side of the fourteenth resistor is connected to one side of the second iron-core inductor, and the other side of the second iron-core inductor is connected to the LX pin of the second DC-DC converter;

[0042] One side of the fifteenth resistor is connected to the FB / OUT pin of the second DC-DC converter, and the other side of the fifteenth resistor is connected to the ground;

[0043] One side of the nineteenth capacitor is connected to the VIN pin of the second DC-DC converter, and the other side of the nineteenth capacitor is connected to the ground;

[0044] One side of the twentieth capacitor is connected to a VIN pin of the second DC-DC converter, and the other side of the twentieth capacitor is connected to the ground;

[0045] One side of the twenty-first capacitor is connected to a BS pin of the second DC-DC converter, and the other side of the twenty-first capacitor is connected to a LX pin of the second DC-DC converter;

[0046] One side of the twenty-second capacitor is connected to one side of the first core inductor, the twenty-second capacitor is connected to a FB / OUT pin of the second DC-DC converter, and a GND pin of the second DC-DC converter is connected to the ground;

[0047] The second electrolytic capacitor, the twenty-third capacitor, the twenty-fourth capacitor, the twenty-fifth capacitor and the twenty-sixth capacitor are connected in parallel, a positive electrode of the second electrolytic capacitor is connected to one side of the twenty-second capacitor, one side of the twenty-sixth capacitor is connected to the positive electrode of the second electrolytic capacitor, and the other side of the twenty-sixth capacitor is connected to the ground.

[0048] Further, the power measurement circuit comprises a twenty-seventh capacitor, a twenty-eighth capacitor, a twenty-ninth capacitor, a thirtieth capacitor, a thirty-first capacitor, a thirty-second capacitor, a P-channel field effect transistor, a first transistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a thirtieth resistor, a thirty-first resistor and a shunt / power monitor;

[0049] One side of the twenty-seventh capacitor is connected to one side of the twenty-eighth capacitor and one side of the twenty-sixth capacitor respectively, the other side of the twenty-seventh capacitor is connected to the other side of the twenty-eighth capacitor and the ground;

[0050] One side of the sixteenth resistor is connected to a fourth pin of the P-channel field effect transistor, and the other side of the sixteenth resistor is connected to one side of the twenty-eighth capacitor and a first pin of the P-channel field effect transistor respectively;

[0051] One side of the seventeenth resistor is connected to the first pin of the P-channel field effect transistor, and the other side of the seventeenth resistor is connected to an eighth pin of the P-channel field effect transistor;

[0052] One side of the eighteenth resistor is connected to the fourth pin of the P-channel field effect transistor, and the other side of the eighteenth resistor is connected to a collector of the first transistor;

[0053] One side of the nineteenth resistor is connected to the PB6 pin of the single chip microcomputer, and the other side of the nineteenth resistor is connected to the base of the first transistor;

[0054] One side of the 20th resistor is connected to the base of the first transistor, and the other side of the 20th resistor is connected to the emitter of the first transistor and is grounded;

[0055] The first pin of the P-channel field effect transistor is respectively connected to the second pin of the P-channel field effect transistor and the third pin of the P-channel field effect transistor, and the eighth pin of the P-channel field effect transistor is respectively connected to the seventh pin of the P-channel field effect transistor, the sixth pin of the P-channel field effect transistor and the fifth pin of the P-channel field effect transistor;

[0056] One side of the twenty-ninth capacitor is connected to the eighth pin of the P-channel field effect transistor, and the other side of the twenty-ninth capacitor is connected to the ground;

[0057] One side of the 30th capacitor is connected to one side of the 29th capacitor, and the other side of the 30th capacitor is connected to the ground;

[0058] One side of the 21st resistor is connected to the eighth pin of the P-channel field effect transistor and the IN+ pin of the shunt / power monitor, and the other side of the 20th resistor is connected to the VBUS pin of the shunt / power monitor;

[0059] One side of the 22nd resistor is connected to the IN+ pin of the shunt / power monitor, and the other side of the 22nd resistor is connected to the INA226_IN- pin;

[0060] One side of the thirty-first capacitor is connected to the IN+ pin of the shunt / power monitor, and the other side of the thirty-first capacitor is connected to the INA226_IN- pin;

[0061] The GND pin of the shunt / power monitor is connected to the VS pin of the shunt / power monitor via a thirty-second capacitor, and the GND pin of the shunt / power monitor is connected to the ground, and the VS pin of the shunt / power monitor is connected to the power supply;

[0062] One side of the twenty-third resistor is connected to a power supply, and the other side of the twenty-third resistor is connected to the A1 pin of the current shunt / power monitor;

[0063] One side of the twenty-fourth resistor is connected to a power supply, and the other side of the twenty-fourth resistor is connected to the A1 pin of the current shunt / power monitor;

[0064] One side of the twenty-fifth resistor is connected to a power supply, and the other side of the twenty-fifth resistor is connected to the A0 pin of the current shunt / power monitor;

[0065] One side of the twenty-sixth resistor is connected to a power supply, and the other side of the twenty-sixth resistor is connected to the A0 pin of the current shunt / power monitor;

[0066] One side of the twenty-seventh resistor is connected to a power supply, and the other side of the twenty-seventh resistor is connected to an Alert pin of the current shunt / power monitor;

[0067] One side of the twenty-eighth resistor is connected to a power supply, and the other side of the twenty-eighth resistor is connected to an SDA pin of the current shunt / power monitor;

[0068] One side of the twenty-ninth resistor is connected to a power supply, and the other side of the twenty-ninth resistor is connected to the SCL pin of the shunt / power monitor;

[0069] One side of the 30th resistor is connected to the PA12 pin of the single chip microcomputer, and the other side of the 30th resistor is connected to the SDA pin of the shunt / power monitor;

[0070] One side of the thirty-first resistor is connected to the PA11 pin of the single chip microcomputer, and the other side of the thirty-first resistor is connected to the SCL pin of the shunt / power monitor.

[0071] The detection circuit for the PCBA board also includes a 485 module and a USB to TTL circuit;

[0072] The 485 module includes a first 485 circuit and a second 485 circuit;

[0073] The first 485 circuit is connected to the control module, and the first 485 circuit is used to realize communication between the detection circuit and the display device;

[0074] The second 485 circuit is connected to the PCBA board, and the second 485 circuit is used to realize the communication between the PCBA board and the display device, and can also detect whether the PCBA circuit communication is abnormal;

[0075] The first 485 circuit and the second 485 circuit are respectively electrically connected to the display device;

[0076] The USB to TTL circuit is connected to the first conversion circuit and the PCBA board to be tested, respectively, and is used to detect whether the USB interface of the PCBA board to be tested is normal.

[0077] Further, the first 485 circuit includes a thirty-second resistor, a thirty-third resistor, a thirty-fourth resistor, a thirty-fifth resistor, a thirty-sixth resistor, a thirty-seventh resistor, a thirty-eighth resistor, a thirty-ninth resistor, a fortieth resistor, a forty-first resistor, a forty-second resistor, a first RS485 transceiver, a second transistor, a first TVS transient voltage suppressor diode and a thirty-third capacitor;

[0078] One side of the thirty-second resistor is connected to the RX pin of the first RS485 transceiver, and the other side of the thirty-second resistor is connected to the PA3 pin of the single-chip microcomputer;

[0079] One side of the thirty-third resistor is connected to the TX pin of the first RS485 transceiver, and the other side of the thirty-third resistor is connected to the PA2 pin of the single-chip microcomputer;

[0080] One side of the thirty-fourth resistor is connected to the RX pin of the first RS485 transceiver, and the other side of the thirty-fourth resistor is connected to a power supply;

[0081] One side of the thirty-fifth resistor is connected to the TX pin of the first RS485 transceiver, and the other side of the thirty-fifth resistor is connected to a power supply;

[0082] One side of the thirty-sixth resistor is connected to the TX pin of the first RS485 transceiver, and the other side of the thirty-sixth resistor is connected to the base of the second transistor;

[0083] One side of the thirty-seventh resistor is connected to the base of the second transistor, and the other side of the thirty-seventh resistor is connected to the emitter of the second transistor and to a ground;

[0084] One side of the thirty-eighth resistor is connected to the collector of the second transistor, the RE pin of the first RS485 transceiver and the TE pin of the first RS485 transceiver respectively, and the other side of the thirty-eighth resistor is connected to the VCC pin of the first RS485 transceiver and to a power supply;

[0085] One side of the thirty-third capacitor is connected to a power supply, and the other side of the thirty-third capacitor is connected to a ground;

[0086] One side of the thirty-ninth resistor is connected to the A pin of the RS485 transceiver, and the other side of the thirty-ninth resistor is connected to one side of the forty-first resistor and one side of the forty-second resistor respectively;

[0087] One side of the fortieth resistor is connected to the B pin of the RS485 transceiver, and the other side of the fortieth resistor is connected to the other side of the forty-second resistor and one side of the forty-third resistor respectively;

[0088] Another side of the forty-first resistor is connected with the power supply, and another side of the forty-second resistor is connected with the ground.

[0089] One side of the first TVS transient voltage suppressor is connected with one side of the forty-second resistor, and another side of the first TVS transient voltage suppressor is connected with another side of the forty-second resistor.

[0090] Further, the second 485 circuit comprises a forty-third resistor, a forty-fourth resistor, a forty-fifth resistor, a forty-sixth resistor, a forty-seventh resistor, a forty-eighth resistor, a forty-ninth resistor, a fiftieth resistor, a fifty-first resistor, a fifty-second resistor, a fifty-third resistor, a second RS485 transceiver, a third transistor, a second TVS transient voltage suppressor and a thirty-fourth capacitor.

[0091] One side of the forty-third resistor is connected with an RX pin of the second RS485 transceiver, and another side of the forty-third resistor is connected with another side of the seventh resistor.

[0092] One side of the forty-fourth resistor is connected with a TX pin of the second RS485 transceiver, and another side of the forty-fourth resistor is connected with another side of the eighth resistor.

[0093] One side of the forty-fifth resistor is connected with the RX pin of the second RS485 transceiver, and another side of the forty-fifth resistor is connected with the power supply.

[0094] One side of the forty-sixth resistor is connected with the TX pin of the second RS485 transceiver, and another side of the forty-sixth resistor is connected with the power supply.

[0095] One side of the forty-seventh resistor is connected with the TX pin of the second RS485 transceiver, and another side of the forty-seventh resistor is connected with a base of the third transistor.

[0096] One side of the forty-eighth resistor is connected with a base of the second transistor, another side of the forty-eighth resistor is connected with an emitter of the third transistor, and is connected with the ground.

[0097] One side of the forty-ninth resistor is connected with a collector of the third transistor, a RE pin of the second RS485 transceiver and a TE pin of the second RS485 transceiver respectively, and another side of the forty-ninth resistor is connected with a VCC pin of the second RS485 transceiver, and is connected with the power supply.

[0098] One side of the thirty-fourth capacitor is connected with the power supply, and another side of the thirty-fourth capacitor is connected with the ground.

[0099] One side of the fiftieth resistor is connected to the A pin of the RS485 transceiver, and the other side of the fiftieth resistor is connected to one side of the fifty-second resistor and one side of the fifty-third resistor, respectively;

[0100] One side of the fifty-first resistor is connected to the B pin of the RS485 transceiver, and the other side of the fifty-first resistor is connected to the other side of the fifty-third resistor and one side of the fifty-fourth resistor, respectively;

[0101] The other side of the fifty-first resistor is connected to a power supply, and the other side of the fifty-second resistor is grounded;

[0102] One side of the second TVS transient suppression diode is connected to one side of the fifty-third resistor, and the other side of the second TVS transient suppression diode is connected to the other side of the fifty-third resistor.

[0103] Further, the USB to TTL circuit includes a fifty-fifth resistor, a fifty-sixth resistor, a fifty-seventh resistor, a fifty-eighth resistor, a fifty-ninth resistor, a sixtieth resistor, a sixty-first resistor, a sixty-second resistor, a sixty-third resistor, a sixty-fourth resistor, a sixty-fifth resistor, a sixty-sixth resistor, a sixty-seventh resistor, a sixty-eighth resistor, a sixty-ninth resistor, a seventieth resistor, a seventy-first resistor, a seventy-second resistor, a seventy-third resistor, a seventy-fourth resistor, a seventy-fifth resistor, a seventy-sixth resistor, a seventy-seventh resistor, a seventy-eighth resistor, a thirty-fifth capacitor, a thirty-sixth capacitor, a thirty-seventh capacitor, a thirty-eighth capacitor, a thirty-ninth capacitor, a fortieth capacitor, a forty-first capacitor, a forty-second capacitor, a forty-third capacitor, a forty-fourth capacitor, a forty-fifth capacitor, a forty-sixth capacitor, a forty-seventh capacitor, a forty-eighth capacitor, a forty-ninth capacitor, a first USB to serial chip, a second USB to serial chip, a third USB to serial chip, a first passive crystal oscillator, a second passive crystal oscillator, a third passive crystal oscillator, a USB interface, a first copper core inductor, and a second copper core inductor;

[0104] One side of the fifty-fifth resistor is connected to the UD+ pin of the first USB to serial chip, and one side of the fifty-sixth resistor is connected to the UD- pin of the first USB to serial chip;

[0105] One side of the fifty-seventh resistor is connected to a power supply, and the other side of the fifty-seventh resistor is connected to the other side of the fifty-sixth resistor;

[0106] One side of the thirty-fifth capacitor is connected to ground, and the other side of the thirty-fifth capacitor is connected to the V3 pin of the first USB to serial chip and a power supply;

[0107] One side of the fifty-eighth resistor is connected with the XI pin of the first USB-to-serial chip, and the other side of the fifty-eighth resistor is connected with the XO pin of the first USB-to-serial chip;

[0108] One side of the thirty-sixth capacitor is connected with the XI pin of the first USB-to-serial chip, and the other side of the thirty-sixth capacitor is connected with the second pin of the first passive crystal oscillator and the ground;

[0109] One side of the thirty-seventh capacitor is connected with the XO pin of the first USB-to-serial chip, and the other side of the thirty-seventh capacitor is connected with the fourth pin of the first passive crystal oscillator and the ground;

[0110] The third pin of the first passive crystal oscillator is connected with the XI pin of the first USB-to-serial chip, and the first pin of the first passive crystal oscillator is connected with the XO pin of the first USB-to-serial chip;

[0111] One side of the thirty-eighth capacitor is connected with the VCC pin of the first USB-to-serial chip, and the other side of the thirty-eighth capacitor is connected with the ground;

[0112] One side of the fifty-ninth resistor is connected with the VCC pin of the first USB-to-serial chip, and the other side of the fifty-ninth resistor is connected with the power supply;

[0113] The TXD pin of the first USB-to-serial chip is connected with the RXD pin of the first USB-to-serial chip through the sixtieth resistor, and the GND pin of the first USB-to-serial chip is connected with the ground;

[0114] One side of the sixty-first resistor is connected with the UD+ pin of the second USB-to-serial chip, and one side of the sixty-second resistor is connected with the UD- pin of the second USB-to-serial chip;

[0115] One side of the sixty-third resistor is connected with the power supply, and the other side of the sixty-third resistor is connected with the other side of the sixty-second resistor;

[0116] One side of the thirty-ninth capacitor is connected with the ground, and the other side of the thirty-ninth capacitor is connected with the V3 pin of the second USB-to-serial chip and the power supply;

[0117] One side of the sixty-fourth resistor is connected with the XI pin of the second USB-to-serial chip, and the other side of the sixty-fourth resistor is connected with the XO pin of the second USB-to-serial chip;

[0118] One side of the fortieth capacitor is connected with the XI pin of the second USB-to-serial chip, and the other side of the fortieth capacitor is connected with the second pin of the second passive crystal oscillator and the ground;

[0119] One side of the forty-first capacitor is connected with the XO pin of the second USB-to-serial chip, and the other side of the forty-first capacitor is connected with the fourth pin of the second passive crystal oscillator and the ground;

[0120] The third pin of the second passive crystal oscillator is connected with the XI pin of the second USB-to-serial chip, and the first pin of the second passive crystal oscillator is connected with the XO pin of the second USB-to-serial chip;

[0121] One side of the forty-second capacitor is connected with the VCC pin of the second USB-to-serial chip, and the other side of the forty-second capacitor is connected with the ground;

[0122] One side of the sixty-fifth resistor is connected with the VCC pin of the second USB-to-serial chip, and the other side of the sixty-fifth resistor is connected with the power supply;

[0123] The TXD pin of the second USB-to-serial chip is connected with the RXD pin of the second USB-to-serial chip through the sixty-sixth resistor, and the GND pin of the second USB-to-serial chip is connected with the ground;

[0124] One side of the sixty-first resistor is connected with one side of the sixty-sixth resistor through the sixty-seventh resistor;

[0125] The other side of the sixty-first resistor is connected with the other side of the sixty-sixth resistor through the sixty-eighth resistor;

[0126] One side of the sixty-ninth resistor is connected with the UD+ pin of the third USB-to-serial chip, and one side of the seventy-first resistor is connected with the UD- pin of the third USB-to-serial chip;

[0127] One side of the seventy-first resistor is connected with the power supply, and the other side of the seventy-first resistor is connected with the other side of the seventy-first resistor;

[0128] One side of the forty-third capacitor is connected with the ground, and the other side of the forty-third capacitor is connected with the V3 pin of the third USB-to-serial chip and the power supply;

[0129] One side of the seventy-second resistor is connected with the XI pin of the third USB-to-serial chip, and the other side of the seventy-second resistor is connected with the XO pin of the third USB-to-serial chip;

[0130] One side of the forty-fourth capacitor is connected with the XI pin of the third USB-to-serial chip, and the other side of the forty-fourth capacitor is connected with the second pin of the third passive crystal oscillator and the ground;

[0131] One side of the forty-fifth capacitor is connected with the XO pin of the third USB-to-serial chip, and the other side of the forty-fifth capacitor is connected with the fourth pin of the third passive crystal oscillator and the ground;

[0132] The third pin of the third passive crystal oscillator is connected with the XI pin of the third USB-to-serial chip, and the first pin of the third passive crystal oscillator is connected with the XO pin of the third USB-to-serial chip;

[0133] One side of the forty-sixth capacitor is connected with the VCC pin of the third USB-to-serial chip, and the other side of the forty-sixth capacitor is connected with the ground;

[0134] One side of the seventy-third resistor is connected with the VCC pin of the third USB-to-serial chip, and the other side of the seventy-third resistor is connected with the power supply;

[0135] The TXD pin of the third USB-to-serial chip is connected with the RXD pin of the third USB-to-serial chip through the seventy-fourth resistor;

[0136] One side of the first copper core inductor is connected with the power supply, and the other side of the first copper core inductor is connected with the USB_OTG_VBUS1 pin;

[0137] One side of the second copper core inductor is connected with the first pin of the USB interface, and the other side of the second copper core inductor is connected with the power supply;

[0138] One side of the seventy-fifth resistor is connected with the second pin of the USB interface, and the other side of the seventy-fifth resistor is connected with the USB3_HOST_DN pin;

[0139] One side of the seventy-sixth resistor is connected with the third pin of the USB interface, and the other side of the seventy-sixth resistor is connected with the USB3_HOST_DP pin;

[0140] One side of the seventy-seventh resistor is connected with the fifth pin of the USB interface, and the other side of the seventy-seventh resistor is connected with the USB3_SSRXN pin;

[0141] One side of the seventy-eighth resistor is connected with the sixth pin of the USB interface, and the other side of the seventy-eighth resistor is connected with the USB3_SSRXP pin;

[0142] One side of the forty-seventh capacitor is connected with the eighth pin of the USB interface, and the other side of the forty-seventh capacitor is connected with the USB3_SSTXN pin;

[0143] One side of the forty-eighth capacitor is connected with the ninth pin of the USB adapter, and the other side of the forty-eighth capacitor is connected with the USB3_SSTXP pin;

[0144] One side of the forty-ninth capacitor is connected with the tenth pin of the USB adapter and the eleventh pin of the USB adapter respectively, the other side of the forty-ninth capacitor is connected with the fourth pin of the USB adapter and the seventh pin of the USB adapter respectively, and is connected with the ground.

[0145] Compared with the prior art, the utility model has the beneficial effects that:

[0146] The utility model provides a detection circuit for PCBA board, including control module, control module is used for controlling the output voltage of power module, power module, power module includes first conversion circuit, second conversion circuit and power measurement circuit, first conversion circuit is connected with control module, first conversion circuit exports power supply and is given with control module power supply, second conversion circuit is connected with power measurement circuit, second conversion circuit exports power supply and is given with power measurement circuit power supply, power measurement circuit is connected with control module and PCBA board to be measured respectively, and power measurement circuit is used for whether the power of PCBA board to be measured is normal.

[0147] The patent can be used to detect whether the power of the PCBA board to be measured is normal by the circuit composed of the control module, the first conversion circuit, the second conversion circuit and the power measurement circuit, so as to judge the performance and safety of the PCBA board to be measured, and to ensure that the design of the PCBA board meets the specifications. BRIEF DESCRIPTION OF DRAWINGS

[0148] The specific implementation of the utility model will be further explained in detail in combination with the drawings, wherein:

[0149] Fig. 1 It is the power module circuit diagram of the utility model,

[0150] Fig. 2 It is the 485 module circuit diagram of the utility model,

[0151] Fig. 3 It is the USB conversion TTL circuit diagram of the utility model,

[0152] In the drawing: 1-power module, 2-485 module, 3-USB conversion TTL circuit, 101-first conversion circuit, 102-second conversion circuit, 103-power measurement circuit. DETAILED DESCRIPTION

[0153] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0154] like Figs. 1-3 As shown, the preferred structure of a detection circuit for a PCBA board described in the present invention.

[0155] The utility model discloses a detection circuit for a PCBA board, comprising a control module, the control module being used to control the output voltage of a power module; a power module, the power module comprising a first conversion circuit, a second conversion circuit, and a power measurement circuit; the first conversion circuit being connected to the control module, the first conversion circuit outputting power to supply power to the control module; the second conversion circuit being connected to the power measurement circuit, the second conversion circuit outputting power to supply power to the power measurement circuit; the power measurement circuit being respectively connected to the control module and the PCBA board to be tested, the power measurement circuit being used to determine whether the power of the PCBA board to be tested is normal.

[0156] The control module includes a single chip microcomputer, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an active crystal oscillator, a button, a first electrostatic protection diode, a second electrostatic protection diode, a three-hole terminal and a four-hole terminal;

[0157] The VDD_1 pin of the single-chip microcomputer, the VDDA pin of the single-chip microcomputer, the VDD_2 pin of the single-chip microcomputer, and the VDD_3 pin of the single-chip microcomputer are all connected to a power supply;

[0158] The VSSA pin of the single chip microcomputer, the VSS_1 pin of the single chip microcomputer and the VSS_2 pin of the single chip microcomputer are all grounded;

[0159] One side of the first resistor is connected to the PF7 pin of the single chip microcomputer, and the other side of the first resistor is connected to the power supply;

[0160] One side of the second resistor is connected to the PF6 pin of the single chip microcomputer, and the other side of the second resistor is grounded;

[0161] One side of the third resistor is connected to the BOOT0 pin of the single chip microcomputer, and the other side of the third resistor is connected to the ground;

[0162] One side of the fourth resistor is connected to the X2 pin of the active crystal oscillator and the PF0 pin of the single-chip microcomputer, and the other side of the fourth resistor is connected to the X1 pin of the active crystal oscillator and the PF1 pin of the single-chip microcomputer;

[0163] One side of the first capacitor is connected to the X1 pin of the active crystal oscillator, the other side of the first capacitor is connected to the GND2 pin of the active crystal oscillator, and is connected to the ground;

[0164] One side of the second capacitor is connected to the X2 pin of the active crystal oscillator, the other side of the second capacitor is connected to the GND1 pin of the active crystal oscillator, and is connected to the ground;

[0165] The third pin of the key is connected to the NRST pin of the single-chip microcomputer, and the fourth pin of the key is connected to the ground;

[0166] One side of the third capacitor is connected to the NRST pin of the single-chip microcomputer, and the other side of the third capacitor is connected to the ground;

[0167] One side of the fifth resistor is connected to the NRST pin of the single-chip microcomputer, and the other side of the fifth resistor is connected to the power supply;

[0168] One side of the sixth resistor is connected to the PB10 pin of the single-chip microcomputer, and the other side of the sixth resistor is connected to the third pin of the three-hole terminal;

[0169] One side of the seventh resistor is connected to the PB11 pin of the single-chip microcomputer, and the other side of the seventh resistor is connected to the second pin of the three-hole terminal;

[0170] One side of the first electrostatic protection diode is connected to the second port of the three-hole terminal, and the other side of the first electrostatic protection diode is connected to the first pin of the three-hole terminal and the ground;

[0171] One side of the second electrostatic protection diode is connected to the third port of the three-hole terminal, and the other side of the second electrostatic protection diode is connected to the ground;

[0172] One side of the eighth resistor is connected to the PB10 pin of the single-chip microcomputer, and one side of the ninth resistor is connected to the PB11 pin of the single-chip microcomputer, and the first port of the three-hole terminal is connected to the ground;

[0173] The second port of the four-hole terminal is connected to the SWCLK pin of the single-chip microcomputer, the fourth pin of the four-hole terminal is connected to the SWDIO pin of the single-chip microcomputer, and the third port of the four-hole terminal is connected to the ground;

[0174] One side of the fourth capacitor is connected to the ground, and the other side of the fourth capacitor is connected to the first port of the four-hole terminal and the power supply;

[0175] The fifth capacitor, the sixth capacitor, the seventh capacitor, the eighth capacitor, the ninth capacitor and the tenth capacitor are connected in parallel, one side of the fifth capacitor is connected to a power supply, and one side of the tenth capacitor is connected to a ground.

[0176] As shown in Fig. 1 The first conversion circuit outputs voltage in a step-down manner;

[0177] The second conversion circuit outputs voltage in a step-down manner.

[0178] Specifically, the first conversion circuit comprises a tenth resistor, an eleventh resistor, a twelfth resistor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a first core inductor and a first DC-DC converter.

[0179] One side of the tenth resistor is connected to a VIN pin of the first DC-DC converter, and the other side of the tenth resistor is connected to an EN pin of the first DC-DC converter.

[0180] One side of the eleventh resistor is connected to an FB / OUT pin of the first DC-DC converter, the other side of the eleventh resistor is connected to one side of the first core inductor, and the other side of the first core inductor is connected to an LX pin of the first DC-DC converter.

[0181] One side of the twelfth resistor is connected to the FB / OUT pin of the first DC-DC converter, and the other side of the twelfth resistor is connected to a ground.

[0182] One side of the eleventh capacitor is connected to the VIN pin of the first DC-DC converter, and the other side of the eleventh capacitor is connected to the ground.

[0183] One side of the twelfth capacitor is connected to the VIN pin of the first DC-DC converter, and the other side of the twelfth capacitor is connected to the ground.

[0184] One side of the thirteenth capacitor is connected to a BS pin of the first DC-DC converter, and the other side of the thirteenth capacitor is connected to an LX pin of the first DC-DC converter.

[0185] One side of the fourteenth capacitor is connected to one side of the first core inductor, the fourteenth capacitor is connected to the FB / OUT pin of the first DC-DC converter, and a GND pin of the first DC-DC converter is connected to the ground.

[0186] The first electrolytic capacitor, the fifteenth capacitor, the sixteenth capacitor, the seventeenth capacitor and the eighteenth capacitor are connected in parallel, one side of the fourteenth capacitor is connected to the positive electrode of the first electrolytic capacitor, one side of the eighteenth capacitor is connected to the positive electrode of the second electrolytic capacitor, and the other side of the eighteenth capacitor is connected to the ground.

[0187] Specifically, the second conversion circuit includes a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a nineteenth capacitor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a twenty-sixth capacitor, a second core inductor, a second electrolytic capacitor and a second DC-DC converter.

[0188] One side of the thirteenth resistor is connected to the VIN pin of the second DC-DC converter, and the other side of the thirteenth resistor is connected to the EN pin of the second DC-DC converter.

[0189] One side of the fourteenth resistor is connected to the FB / OUT pin of the second DC-DC converter, the other side of the fourteenth resistor is connected to one side of the second core inductor, and the other side of the second core inductor is connected to the LX pin of the second DC-DC converter.

[0190] One side of the fifteenth resistor is connected to the FB / OUT pin of the second DC-DC converter, and the other side of the fifteenth resistor is connected to the ground.

[0191] One side of the nineteenth capacitor is connected to the VIN pin of the second DC-DC converter, and the other side of the nineteenth capacitor is connected to the ground.

[0192] One side of the twentieth capacitor is connected to the VIN pin of the second DC-DC converter, and the other side of the twentieth capacitor is connected to the ground.

[0193] One side of the twenty-first capacitor is connected to the BS pin of the second DC-DC converter, and the other side of the twenty-first capacitor is connected to the LX pin of the second DC-DC converter.

[0194] One side of the twenty-second capacitor is connected to one side of the first core inductor, the twenty-second capacitor is connected to the FB / OUT pin of the second DC-DC converter, and the GND pin of the second DC-DC converter is connected to the ground.

[0195] The second electrolytic capacitor, the twenty-third capacitor, the twenty-fourth capacitor, the twenty-fifth capacitor and the twenty-sixth capacitor are connected in parallel, one side of the twenty-second capacitor is connected to the positive electrode of the second electrolytic capacitor, one side of the twenty-sixth capacitor is connected to the positive electrode of the second electrolytic capacitor, and the other side of the twenty-sixth capacitor is connected to the ground.

[0196] Specifically, the power measurement circuit comprises the twenty-seventh capacitor, the twenty-eighth capacitor, the twenty-ninth capacitor, the thirtieth capacitor, the thirty-first capacitor, the thirty-second capacitor, a P-channel field effect transistor, a first transistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a thirtieth resistor, a thirty-first resistor, and a shunt / power monitor;

[0197] One side of the twenty-seventh capacitor is connected to one side of the twenty-eighth capacitor and one side of the twenty-sixth capacitor respectively, and the other side of the twenty-seventh capacitor is connected to the other side of the twenty-eighth capacitor and to ground;

[0198] One side of the sixteenth resistor is connected to the fourth pin of the P-channel field effect transistor, and the other side of the sixteenth resistor is connected to one side of the twenty-eighth capacitor and the first pin of the P-channel field effect transistor respectively;

[0199] One side of the seventeenth resistor is connected to the first pin of the P-channel field effect transistor, and the other side of the seventeenth resistor is connected to the eighth pin of the P-channel field effect transistor;

[0200] One side of the eighteenth resistor is connected to the fourth pin of the P-channel field effect transistor, and the other side of the eighteenth resistor is connected to the collector of the first transistor;

[0201] One side of the nineteenth resistor is connected to the PB6 pin of the single-chip microcomputer, and the other side of the nineteenth resistor is connected to the base of the first transistor;

[0202] One side of the twentieth resistor is connected to the base of the first transistor, and the other side of the twentieth resistor is connected to the emitter of the first transistor and to ground;

[0203] The first pin of the P-channel field effect transistor is connected to the second pin of the P-channel field effect transistor and the third pin of the P-channel field effect transistor respectively, and the eighth pin of the P-channel field effect transistor is connected to the seventh pin of the P-channel field effect transistor, the sixth pin of the P-channel field effect transistor, and the fifth pin of the P-channel field effect transistor respectively;

[0204] One side of the twenty-ninth capacitor is connected to the eighth pin of the P-channel field effect transistor, and the other side of the twenty-ninth capacitor is connected to ground;

[0205] One side of the thirtieth capacitor is connected to one side of the twenty-ninth capacitor, and the other side of the thirtieth capacitor is connected to ground;

[0206] one side of the twenty-first resistor is connected with the eighth pin of the P-channel field effect transistor and the IN+ pin of the shunt / power monitor, and the other side of the twenty-first resistor is connected with the VBUS pin of the shunt / power monitor;

[0207] one side of the twenty-second resistor is connected with the IN+ pin of the shunt / power monitor, and the other side of the twenty-second resistor is connected with the INA226_IN- pin;

[0208] one side of the thirty-first capacitor is connected with the IN+ pin of the shunt / power monitor, and the other side of the thirty-first capacitor is connected with the INA226_IN- pin;

[0209] the GND pin of the shunt / power monitor is connected with the VS pin of the shunt / power monitor through the thirty-second capacitor, and the GND pin of the shunt / power monitor is connected with the ground, and the VS pin of the shunt / power monitor is connected with the power supply;

[0210] one side of the twenty-third resistor is connected with the power supply, and the other side of the twenty-third resistor is connected with the A1 pin of the shunt / power monitor;

[0211] one side of the twenty-fourth resistor is connected with the power supply, and the other side of the twenty-fourth resistor is connected with the A1 pin of the shunt / power monitor;

[0212] one side of the twenty-fifth resistor is connected with the power supply, and the other side of the twenty-fifth resistor is connected with the A0 pin of the shunt / power monitor;

[0213] one side of the twenty-sixth resistor is connected with the power supply, and the other side of the twenty-sixth resistor is connected with the A0 pin of the shunt / power monitor;

[0214] one side of the twenty-seventh resistor is connected with the power supply, and the other side of the twenty-seventh resistor is connected with the Alert pin of the shunt / power monitor;

[0215] one side of the twenty-eighth resistor is connected with the power supply, and the other side of the twenty-eighth resistor is connected with the SDA pin of the shunt / power monitor;

[0216] one side of the twenty-ninth resistor is connected with the power supply, and the other side of the twenty-ninth resistor is connected with the SCL pin of the shunt / power monitor;

[0217] one side of the thirtieth resistor is connected with the PA12 pin of the single-chip microcomputer, and the other side of the thirtieth resistor is connected with the SDA pin of the shunt / power monitor;

[0218] One side of the thirty-first resistor is connected with the PA11 pin of the single-chip microcomputer, and the other side of the thirty-first resistor is connected with the SCL pin of the shunt / power monitor.

[0219] As shown in Figs. 2-3 the detection circuit for the PCBA board further comprises a 485 module and a USB-to-TTL circuit;

[0220] The 485 module comprises a first 485 circuit and a second 485 circuit.

[0221] The first 485 circuit is connected with the control module, and is used for realizing communication between the detection circuit and a display device.

[0222] The second 485 circuit is connected with the PCBA board, and is used for realizing communication between the PCBA board and the display device, and simultaneously detecting whether the PCBA circuit communication is abnormal.

[0223] The first 485 circuit and the second 485 circuit are respectively connected with the display device through electricity.

[0224] The USB-to-TTL circuit is respectively connected with the first conversion circuit and the PCBA board to be detected, and is used for detecting whether the USB interface of the PCBA board to be detected is normal.

[0225] Specifically, the first 485 circuit comprises a thirty-second resistor, a thirty-third resistor, a thirty-fourth resistor, a thirty-fifth resistor, a thirty-sixth resistor, a thirty-seventh resistor, a thirty-eighth resistor, a thirty-ninth resistor, a fortieth resistor, a forty-first resistor, a forty-second resistor, a first RS485 transceiver, a second transistor, a first TVS transient suppression diode and a thirty-third capacitor.

[0226] One side of the thirty-second resistor is connected with the RX pin of the first RS485 transceiver, and the other side of the thirty-second resistor is connected with the PA3 pin of the single-chip microcomputer.

[0227] One side of the thirty-third resistor is connected with the TX pin of the first RS485 transceiver, and the other side of the thirty-third resistor is connected with the PA2 pin of the single-chip microcomputer.

[0228] One side of the thirty-fourth resistor is connected with the RX pin of the first RS485 transceiver, and the other side of the thirty-fourth resistor is connected with a power supply.

[0229] One side of the thirty-fifth resistor is connected with the TX pin of the first RS485 transceiver, and the other side of the thirty-fifth resistor is connected with the power supply.

[0230] One side of the thirty-sixth resistor is connected to the TX pin of the first RS485 transceiver, and the other side of the thirty-sixth resistor is connected to the base of the second transistor;

[0231] One side of the thirty-seventh resistor is connected to the base of the second transistor, and the other side of the thirty-seventh resistor is connected to the emitter of the second transistor and to the ground;

[0232] One side of the thirty-eighth resistor is connected to the collector of the second transistor, the RE pin of the first RS485 transceiver, and the TE pin of the first RS485 transceiver, respectively, and the other side of the thirty-eighth resistor is connected to the VCC pin of the first RS485 transceiver and to the power supply;

[0233] One side of the thirty-third capacitor is connected to the power supply, and the other side of the thirty-third capacitor is connected to the ground;

[0234] One side of the thirty-ninth resistor is connected to the A pin of the RS485 transceiver, and the other side of the thirty-ninth resistor is connected to one side of the forty-first resistor and one side of the forty-second resistor, respectively;

[0235] One side of the fortieth resistor is connected to the B pin of the RS485 transceiver, and the other side of the fortieth resistor is connected to the other side of the forty-second resistor and one side of the forty-third resistor, respectively;

[0236] The other side of the fortieth resistor is connected to the power supply, and the other side of the forty-third resistor is connected to the ground;

[0237] One side of the first TVS transient voltage suppression diode is connected to one side of the forty-second resistor, and the other side of the first TVS transient voltage suppression diode is connected to the other side of the forty-second resistor.

[0238] Specifically, the second 485 circuit includes a forty-third resistor, a forty-fourth resistor, a forty-fifth resistor, a forty-sixth resistor, a forty-seventh resistor, a forty-eighth resistor, a forty-ninth resistor, a fiftieth resistor, a fifty-first resistor, a fifty-second resistor, a fifty-third resistor, a second RS485 transceiver, a third transistor, a second TVS transient voltage suppression diode, and a thirty-fourth capacitor;

[0239] One side of the forty-third resistor is connected to the RX pin of the second RS485 transceiver, and the other side of the forty-third resistor is connected to the other side of the seventh resistor;

[0240] One side of the forty-fourth resistor is connected to the TX pin of the second RS485 transceiver, and the other side of the forty-fourth resistor is connected to the other side of the eighth resistor;

[0241] One side of the forty-fifth resistor is connected to the RX pin of the second RS485 transceiver, and the other side of the forty-fifth resistor is connected to a power supply;

[0242] One side of the forty-sixth resistor is connected to the TX pin of the second RS485 transceiver, and the other side of the forty-sixth resistor is connected to a power supply;

[0243] One side of the forty-seventh resistor is connected to the TX pin of the second RS485 transceiver, and the other side of the forty-seventh resistor is connected to the base of the third transistor;

[0244] One side of the forty-eighth resistor is connected to the base of the second transistor, and the other side of the forty-eighth resistor is connected to the emitter of the third transistor and to a ground;

[0245] One side of the forty-ninth resistor is connected to the collector of the third transistor, the RE pin of the second RS485 transceiver, and the TE pin of the second RS485 transceiver, respectively, and the other side of the forty-ninth resistor is connected to the VCC pin of the second RS485 transceiver and to a power supply;

[0246] One side of the thirty-fourth capacitor is connected to a power supply, and the other side of the thirty-fourth capacitor is connected to a ground;

[0247] One side of the fiftieth resistor is connected to the A pin of the RS485 transceiver, and the other side of the fiftieth resistor is connected to one side of the fifty-second resistor and one side of the fifty-third resistor, respectively;

[0248] One side of the fifty-first resistor is connected to the B pin of the RS485 transceiver, and the other side of the fifty-first resistor is connected to the other side of the fifty-third resistor and one side of the fifty-fourth resistor, respectively;

[0249] The other side of the fifty-first resistor is connected to a power supply, and the other side of the fifty-second resistor is connected to a ground;

[0250] One side of the second TVS transient voltage suppressor diode is connected to one side of the fifty-third resistor, and the other side of the second TVS transient voltage suppressor diode is connected to the other side of the fifty-third resistor.

[0251] Specifically, the USB-to-TTL circuit includes a 55th resistor, a 56th resistor, a 57th resistor, a 58th resistor, a 59th resistor, a 60th resistor, a 61st resistor, a 62nd resistor, a 63rd resistor, a 64th resistor, a 65th resistor, a 66th resistor, a 67th resistor, a 68th resistor, a 69th resistor, a 70th resistor, a 71st resistor, a 72nd resistor, a 73rd resistor, a 74th resistor, a 75th resistor, a 76th resistor, a 77th resistor, a 78th resistor, a 35th capacitor, a 36th capacitor, a 37th capacitor, a 38th capacitor, a 39th capacitor, a 40th capacitor, a 41st capacitor, a 42nd capacitor, a 43rd capacitor, a 44th capacitor, a 45th capacitor, a 46th capacitor, a 47th capacitor, a 48th capacitor, a 49th capacitor, a first USB-to-serial chip, a second USB-to-serial chip, a third USB-to-serial chip, a first passive crystal oscillator, a second passive crystal oscillator, a third passive crystal oscillator, a USB interface, a first copper core inductor, and a second copper core inductor;

[0252] One side of the 55th resistor is connected to a UD+ pin of the first USB-to-serial chip, and one side of the 56th resistor is connected to a UD- pin of the first USB-to-serial chip.

[0253] One side of the 57th resistor is connected to a power supply, and the other side of the 57th resistor is connected to the other side of the 56th resistor.

[0254] One side of the 35th capacitor is connected to a ground, and the other side of the 35th capacitor is connected to a V3 pin of the first USB-to-serial chip and a power supply.

[0255] One side of the 58th resistor is connected to a XI pin of the first USB-to-serial chip, and the other side of the 58th resistor is connected to a XO pin of the first USB-to-serial chip.

[0256] One side of the 36th capacitor is connected to the XI pin of the first USB-to-serial chip, and the other side of the 36th capacitor is connected to a second pin of the first passive crystal oscillator and the ground.

[0257] One side of the 37th capacitor is connected to the XO pin of the first USB-to-serial chip, and the other side of the 37th capacitor is connected to a fourth pin of the first passive crystal oscillator and the ground.

[0258] A third pin of the first passive crystal oscillator is connected to the XI pin of the first USB-to-serial chip, and a first pin of the first passive crystal oscillator is connected to the XO pin of the first USB-to-serial chip.

[0259] One side of the thirty-eighth capacitor is connected to the VCC pin of the first USB-to-serial chip, and the other side of the thirty-eighth capacitor is connected to the ground;

[0260] One side of the fifty-ninth resistor is connected to the VCC pin of the first USB-to-serial chip, and the other side of the fifty-ninth resistor is connected to the power supply;

[0261] The TXD pin of the first USB-to-serial chip is connected to the RXD pin of the first USB-to-serial chip through the sixtieth resistor, and the GND pin of the first USB-to-serial chip is connected to the ground;

[0262] One side of the sixty-first resistor is connected to the UD+ pin of the second USB-to-serial chip, and one side of the sixty-second resistor is connected to the UD- pin of the second USB-to-serial chip;

[0263] One side of the sixty-third resistor is connected to the power supply, and the other side of the sixty-third resistor is connected to the other side of the sixty-second resistor;

[0264] One side of the thirty-ninth capacitor is connected to the ground, and the other side of the thirty-ninth capacitor is connected to the V3 pin of the second USB-to-serial chip and the power supply;

[0265] One side of the sixty-fourth resistor is connected to the XI pin of the second USB-to-serial chip, and the other side of the sixty-fourth resistor is connected to the XO pin of the second USB-to-serial chip;

[0266] One side of the fortieth capacitor is connected to the XI pin of the second USB-to-serial chip, and the other side of the fortieth capacitor is connected to the second pin of the second passive crystal oscillator and the ground;

[0267] One side of the forty-first capacitor is connected to the XO pin of the second USB-to-serial chip, and the other side of the forty-first capacitor is connected to the fourth pin of the second passive crystal oscillator and the ground;

[0268] The third pin of the second passive crystal oscillator is connected to the XI pin of the second USB-to-serial chip, and the first pin of the second passive crystal oscillator is connected to the XO pin of the second USB-to-serial chip;

[0269] One side of the forty-second capacitor is connected to the VCC pin of the second USB-to-serial chip, and the other side of the forty-second capacitor is connected to the ground;

[0270] One side of the sixty-fifth resistor is connected to the VCC pin of the second USB-to-serial chip, and the other side of the sixty-fifth resistor is connected to the power supply;

[0271] The TXD pin of the second USB-to-serial chip is connected to the RXD pin of the second USB-to-serial chip through the sixty-sixth resistor, and the GND pin of the second USB-to-serial chip is connected to ground;

[0272] One side of the sixty-first resistor is connected to one side of the sixty-sixth resistor through the sixty-seventh resistor;

[0273] The other side of the sixty-first resistor is connected to the other side of the sixty-sixth resistor through the sixty-eighth resistor;

[0274] One side of the sixty-ninth resistor is connected to the UD+ pin of the third USB-to-serial chip, and one side of the seventy-first resistor is connected to the UD- pin of the third USB-to-serial chip;

[0275] One side of the seventy-first resistor is connected to a power supply, and the other side of the seventy-first resistor is connected to the other side of the seventy-first resistor;

[0276] One side of the forty-third capacitor is connected to ground, and the other side of the forty-third capacitor is connected to the V3 pin of the third USB-to-serial chip and to a power supply;

[0277] One side of the seventy-second resistor is connected to the XI pin of the third USB-to-serial chip, and the other side of the seventy-second resistor is connected to the XO pin of the third USB-to-serial chip;

[0278] One side of the forty-fourth capacitor is connected to the XI pin of the third USB-to-serial chip, and the other side of the forty-fourth capacitor is connected to the second pin of the third passive crystal oscillator and to ground;

[0279] One side of the forty-fifth capacitor is connected to the XO pin of the third USB-to-serial chip, and the other side of the forty-fifth capacitor is connected to the fourth pin of the third passive crystal oscillator and to ground;

[0280] The third pin of the third passive crystal oscillator is connected to the XI pin of the third USB-to-serial chip, and the first pin of the third passive crystal oscillator is connected to the XO pin of the third USB-to-serial chip;

[0281] One side of the forty-sixth capacitor is connected to the VCC pin of the third USB-to-serial chip, and the other side of the forty-sixth capacitor is connected to ground;

[0282] One side of the seventy-third resistor is connected to the VCC pin of the third USB-to-serial chip, and the other side of the seventy-third resistor is connected to a power supply;

[0283] The TXD pin of the third USB-to-serial chip is connected to the RXD pin of the third USB-to-serial chip through the seventy-fourth resistor.

[0284] One side of the first copper core inductor is connected to a power supply, and the other side of the first copper core inductor is connected to a USB_OTG_VBUS1 pin.

[0285] One side of the second copper core inductor is connected to a first pin of the USB interface, and the other side of the second copper core inductor is connected to a power supply.

[0286] One side of the seventy-fifth resistor is connected to a second pin of the USB interface, and the other side of the seventy-fifth resistor is connected to a USB3_HOST_DN pin.

[0287] One side of the seventy-sixth resistor is connected to a third pin of the USB interface, and the other side of the seventy-sixth resistor is connected to a USB3_HOST_DP pin.

[0288] One side of the seventy-seventh resistor is connected to a fifth pin of the USB interface, and the other side of the seventy-seventh resistor is connected to a USB3_SSRXN pin.

[0289] One side of the seventy-eighth resistor is connected to a sixth pin of the USB interface, and the other side of the seventy-eighth resistor is connected to a USB3_SSRXP pin.

[0290] One side of the forty-seventh capacitor is connected to an eighth pin of the USB interface, and the other side of the forty-seventh capacitor is connected to a USB3_SSTXN pin.

[0291] One side of the forty-eighth capacitor is connected to a ninth pin of the USB interface, and the other side of the forty-eighth capacitor is connected to a USB3_SSTXP pin.

[0292] One side of the forty-ninth capacitor is respectively connected to a tenth pin of the USB interface and an eleventh pin of the USB interface, and the other side of the forty-ninth capacitor is respectively connected to a fourth pin of the USB interface and a seventh pin of the USB interface, and is connected to ground.

[0293] In a specific implementation, the patent converts a 12V power supply into a 3.3V power supply through the first DC-DC converter to supply power to the control module, feeds corresponding data of a to-be-tested PCBA board detected by a power measurement circuit to a display device, and if a corresponding warning appears on the display device, it indicates that the power of the to-be-tested PCBA board is abnormal. According to the corresponding abnormal data, it is judged whether the to-be-tested PCBA board meets the design specifications, thereby avoiding potential electrical problems and production losses.

[0294] In the patent, the power measurement circuit is powered by a 12V power supply converted to 5V, and the IN+ pin and IN- pin of the shunt / power monitor in the power measurement circuit are connected to the PCBA board to be tested to monitor the power of the PCBA board to be tested.

[0295] In the patent, the PCBA board detection circuit comprises a 485 module; the 485 module is composed of the first 485 circuit and the second 485 circuit, the first 485 circuit is connected with the control module and communicates with the host computer to feed back the corresponding conditions detected by the PCBA board to be tested; and the second 485 circuit is respectively connected with the PCBA board to be tested and the host computer, so as to detect whether the PCBA board to be tested is abnormal in communication or whether an abnormality occurs in the line.

[0296] In the patent, the PCBA board detection circuit further comprises a USB to TTL circuit, the USB to TTL circuit is connected with the PCBA board to be tested, whether the serial port of the circuit is detected by the host computer is used to judge whether the USB interface of the PCBA board to be tested is normal, and the USB to TTL circuit detection is more convenient than the U disk plug-in detection mode.

[0297] Further, the working principle of the power measurement circuit is the working principle of the current transformer in the shunt / power monitor, the current transformer can detect the current of the circuit and convert it into a voltage signal, which is detected through a secondary circuit. In the shunt power monitor, the voltage signal is appropriately amplified and converted, and the power information of the PCBA board can be obtained.

[0298] The PCBA board detection circuit has the advantages that the detection circuit is divided into three parts, the power supply circuit comprises a power measurement circuit, which is used to detect whether the power of the PCBA board circuit is normal, the 485 module is used to detect whether the communication function of the PCBA board circuit is normal, and the USB to TTL circuit is used to detect whether the USB interface of the PCBA board circuit is normal; the power measurement circuit in the power supply circuit adopts a shunt / power monitor to monitor the power of the PCBA board, and displays the corresponding information through a display device; the 485 module is connected with the PCBA board to be tested through the second 485 circuit, and whether the function is normal is judged by whether the PCBA board to be tested can be connected to the display device; and the USB to TTL circuit can be directly inserted into the USB interface of the PCBA board to judge whether the USB function is normal.

[0299] The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form, so any modification, equivalent change and modification made according to the technical essence of the utility model within the technical solution content of the utility model still belong to the scope of the technical solution of the utility model.

Claims

1. A detection circuit for a PCBA board, characterized in that: include: A control module, configured to control the output voltage of the power module; A power supply module, the power supply module comprising a first conversion circuit, a second conversion circuit and a power measurement circuit; The first conversion circuit is connected to the control module, and the first conversion circuit outputs power to supply power to the control module; The second conversion circuit is connected to the power measurement circuit, and the second conversion circuit outputs power to supply power to the power measurement circuit; The power measurement circuit is connected to the control module and the PCBA board to be tested respectively, and the power measurement circuit is used to determine whether the power of the PCBA board to be tested is normal.

2. The detection circuit for a PCBA board according to claim 1, characterized in that: The control module includes a single chip microcomputer, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an active crystal oscillator, a button, a first electrostatic protection diode, a second electrostatic protection diode, a three-hole terminal and a four-hole terminal; The VDD_1 pin of the single-chip microcomputer, the VDDA pin of the single-chip microcomputer, the VDD_2 pin of the single-chip microcomputer, and the VDD_3 pin of the single-chip microcomputer are all connected to a power supply; The VSSA pin of the single chip microcomputer, the VSS_1 pin of the single chip microcomputer and the VSS_2 pin of the single chip microcomputer are all grounded; One side of the first resistor is connected to the PF7 pin of the single chip microcomputer, and the other side of the first resistor is connected to the power supply; One side of the second resistor is connected to the PF6 pin of the single chip microcomputer, and the other side of the second resistor is grounded; One side of the third resistor is connected to the BOOT0 pin of the single chip microcomputer, and the other side of the third resistor is connected to the ground; One side of the fourth resistor is connected to the X2 pin of the active crystal oscillator and the PF0 pin of the single-chip microcomputer, and the other side of the fourth resistor is connected to the X1 pin of the active crystal oscillator and the PF1 pin of the single-chip microcomputer; One side of the first capacitor is connected to the X1 pin of the active crystal oscillator, and the other side of the first capacitor is connected to the GND2 pin of the active crystal oscillator and is also connected to the ground; One side of the second capacitor is connected to the X2 pin of the active crystal oscillator, and the other side of the second capacitor is connected to the GND1 pin of the active crystal oscillator and is also connected to the ground; The third pin of the button is connected to the NRST pin of the microcontroller, and the fourth pin of the button is connected to the ground; One side of the third capacitor is connected to the NRST pin of the single chip microcomputer, and the other side of the third capacitor is connected to the ground; One side of the fifth resistor is connected to the NRST pin of the single chip microcomputer, and the other side of the fifth resistor is connected to the power supply; One side of the sixth resistor is connected to the PB10 pin of the single chip microcomputer, and the other side of the sixth resistor is connected to the third pin of the three-hole terminal; One side of the seventh resistor is connected to the PB11 pin of the single chip microcomputer, and the other side of the seventh resistor is connected to the second pin of the three-hole terminal; One side of the first electrostatic protection diode is connected to the second port of the three-hole terminal, and the other side of the first electrostatic protection diode is connected to the first pin of the three-hole terminal and is grounded; One side of the second electrostatic protection diode is connected to the third port of the three-hole terminal, and the other side of the second electrostatic protection diode is grounded; One side of the eighth resistor is connected to the PB10 pin of the single chip microcomputer, one side of the ninth resistor is connected to the PB11 pin of the single chip microcomputer, and the first port of the three-hole terminal is connected to the ground; The second port of the four-hole terminal is connected to the SWCLK pin of the single-chip microcomputer, the fourth pin of the four-hole terminal is connected to the SWDIO pin of the single-chip microcomputer, and the third port of the four-hole terminal is connected to the ground; One side of the fourth capacitor is connected to the ground, and the other side of the fourth capacitor is connected to the first port of the four-hole terminal and is also connected to a power supply; The fifth capacitor, the sixth capacitor, the seventh capacitor, the eighth capacitor, the ninth capacitor and the tenth capacitor are connected in parallel, one side of the fifth capacitor is connected to a power supply, and one side of the tenth capacitor is connected to the ground.

3. The detection circuit for a PCBA board according to claim 1, characterized in that: The first conversion circuit outputs voltage in a step-down manner; The second conversion circuit outputs voltage in a step-down manner.

4. The detection circuit for a PCBA board according to claim 3, wherein: The first conversion circuit includes a tenth resistor, an eleventh resistor, a twelfth resistor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a first iron core inductor and a first DC-DC converter; One side of the tenth resistor is connected to the VIN pin of the first DC-DC converter, and the other side of the tenth resistor is connected to the EN pin of the first DC-DC converter; One side of the eleventh resistor is connected to the FB / OUT pin of the first DC-DC converter, the other side of the eleventh resistor is connected to one side of the first iron-core inductor, and the other side of the first iron-core inductor is connected to the LX pin of the first DC-DC converter; One side of the twelfth resistor is connected to the FB / OUT pin of the first DC-DC converter, and the other side of the twelfth resistor is connected to the ground; One side of the eleventh capacitor is connected to the VIN pin of the first DC-DC converter, and the other side of the eleventh capacitor is connected to the ground; One side of the twelfth capacitor is connected to the VIN pin of the first DC-DC converter, and the other side of the twelfth capacitor is connected to the ground; One side of the thirteenth capacitor is connected to the BS pin of the first DC-DC converter, and the other side of the thirteenth capacitor is connected to the LX pin of the first DC-DC converter; One side of the fourteenth capacitor is connected to one side of the first iron core inductor, the fourteenth capacitor is connected to the FB / OUT pin of the first DC-DC converter, and the GND pin of the first DC-DC converter is connected to the ground; The first electrolytic capacitor, the fifteenth capacitor, the sixteenth capacitor, the seventeenth capacitor and the eighteenth capacitor are connected in parallel, the positive electrode of the first electrolytic capacitor is connected to one side of the fourteenth capacitor, one side of the eighteenth capacitor is connected to the positive electrode of the first electrolytic capacitor, and the other side of the eighteenth capacitor is connected to the ground.

5. The detection circuit for a PCBA board according to claim 3, characterized in that: The second conversion circuit includes a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a nineteenth capacitor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a twenty-sixth capacitor, a second iron core inductor, a second electrolytic capacitor, and a second DC-DC converter; One side of the thirteenth resistor is connected to the VIN pin of the second DC-DC converter, and the other side of the thirteenth resistor is connected to the EN pin of the second DC-DC converter; One side of the fourteenth resistor is connected to the FB / OUT pin of the second DC-DC converter, the other side of the fourteenth resistor is connected to one side of the second iron-core inductor, and the other side of the second iron-core inductor is connected to the LX pin of the second DC-DC converter; One side of the fifteenth resistor is connected to the FB / OUT pin of the second DC-DC converter, and the other side of the fifteenth resistor is connected to the ground; One side of the nineteenth capacitor is connected to the VIN pin of the second DC-DC converter, and the other side of the nineteenth capacitor is connected to the ground; One side of the 20th capacitor is connected to the VIN pin of the second DC-DC converter, and the other side of the 20th capacitor is connected to the ground; One side of the twenty-first capacitor is connected to the BS pin of the second DC-DC converter, and the other side of the twenty-first capacitor is connected to the LX pin of the second DC-DC converter; One side of the 22nd capacitor is connected to one side of the first iron core inductor, the 22nd capacitor is connected to the FB / OUT pin of the second DC-DC converter, and the GND pin of the second DC-DC converter is connected to the ground; The second electrolytic capacitor, the twenty-third capacitor, the twenty-fourth capacitor, the twenty-fifth capacitor and the twenty-sixth capacitor are connected in parallel, the positive electrode of the second electrolytic capacitor is connected to one side of the twenty-second capacitor, one side of the twenty-sixth capacitor is connected to the positive electrode of the second electrolytic capacitor, and the other side of the twenty-sixth capacitor is connected to the ground.

6. The detection circuit for a PCBA board according to claim 1, characterized in that: The power measurement circuit includes a twenty-seventh capacitor, a twenty-eighth capacitor, a twenty-ninth capacitor, a thirtieth capacitor, a thirty-first capacitor, a thirty-second capacitor, a P-channel field effect transistor, a first transistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a thirtieth resistor, a thirty-first resistor, and a current shunt / power monitor; One side of the 27th capacitor is connected to one side of the 28th capacitor and one side of the 26th capacitor respectively, and the other side of the 27th capacitor is connected to the other side of the 28th capacitor and is also connected to ground; One side of the sixteenth resistor is connected to the fourth pin of the P-channel field effect transistor, and the other side of the sixteenth resistor is respectively connected to one side of the twenty-eighth capacitor and the first pin of the P-channel field effect transistor; One side of the seventeenth resistor is connected to the first pin of the P-channel field effect transistor, and the other side of the seventeenth resistor is connected to the eighth pin of the P-channel field effect transistor; One side of the eighteenth resistor is connected to the fourth pin of the P-channel field effect transistor, and the other side of the eighteenth resistor is connected to the collector of the first transistor; One side of the nineteenth resistor is connected to the PB6 pin of the single chip microcomputer, and the other side of the nineteenth resistor is connected to the base of the first transistor; One side of the 20th resistor is connected to the base of the first transistor, and the other side of the 20th resistor is connected to the emitter of the first transistor and is grounded; The first pin of the P-channel field effect transistor is respectively connected to the second pin of the P-channel field effect transistor and the third pin of the P-channel field effect transistor, and the eighth pin of the P-channel field effect transistor is respectively connected to the seventh pin of the P-channel field effect transistor, the sixth pin of the P-channel field effect transistor and the fifth pin of the P-channel field effect transistor; One side of the twenty-ninth capacitor is connected to the eighth pin of the P-channel field effect transistor, and the other side of the twenty-ninth capacitor is connected to the ground; One side of the 30th capacitor is connected to one side of the 29th capacitor, and the other side of the 30th capacitor is connected to the ground; One side of the 21st resistor is connected to the eighth pin of the P-channel field effect transistor and the IN+ pin of the shunt / power monitor, and the other side of the 20th resistor is connected to the VBUS pin of the shunt / power monitor; One side of the 22nd resistor is connected to the IN+ pin of the shunt / power monitor, and the other side of the 22nd resistor is connected to the INA226_IN- pin; One side of the thirty-first capacitor is connected to the IN+ pin of the shunt / power monitor, and the other side of the thirty-first capacitor is connected to the INA226_IN- pin; The GND pin of the shunt / power monitor is connected to the VS pin of the shunt / power monitor via a thirty-second capacitor, and the GND pin of the shunt / power monitor is connected to the ground, and the VS pin of the shunt / power monitor is connected to the power supply; One side of the twenty-third resistor is connected to a power supply, and the other side of the twenty-third resistor is connected to the A1 pin of the current shunt / power monitor; One side of the twenty-fourth resistor is connected to a power supply, and the other side of the twenty-fourth resistor is connected to the A1 pin of the current shunt / power monitor; One side of the twenty-fifth resistor is connected to a power supply, and the other side of the twenty-fifth resistor is connected to the A0 pin of the current shunt / power monitor; One side of the twenty-sixth resistor is connected to a power supply, and the other side of the twenty-sixth resistor is connected to the A0 pin of the current shunt / power monitor; One side of the twenty-seventh resistor is connected to a power supply, and the other side of the twenty-seventh resistor is connected to an Alert pin of the current shunt / power monitor; One side of the twenty-eighth resistor is connected to a power supply, and the other side of the twenty-eighth resistor is connected to an SDA pin of the current shunt / power monitor; One side of the twenty-ninth resistor is connected to a power supply, and the other side of the twenty-ninth resistor is connected to the SCL pin of the shunt / power monitor; One side of the 30th resistor is connected to the PA12 pin of the single chip microcomputer, and the other side of the 30th resistor is connected to the SDA pin of the shunt / power monitor; One side of the thirty-first resistor is connected to the PA11 pin of the single chip microcomputer, and the other side of the thirty-first resistor is connected to the SCL pin of the shunt / power monitor.

7. A detection circuit for a PCBA board according to claim 1, characterized in that : The detection circuit for the PCBA board also includes a 485 module and a USB to TTL circuit; The 485 module includes a first 485 circuit and a second 485 circuit; The first 485 circuit is connected to the control module, and the first 485 circuit is used to realize communication between the detection circuit and the display device; The second 485 circuit is connected to the PCBA board, and the second 485 circuit is used to realize the communication between the PCBA board and the display device, and can also detect whether the PCBA circuit communication is abnormal; The first 485 circuit and the second 485 circuit are respectively electrically connected to the display device; The USB to TTL circuit is connected to the first conversion circuit and the PCBA board to be tested, respectively, and is used to detect whether the USB interface of the PCBA board to be tested is normal.

8. The detection circuit for a PCBA board according to claim 7, characterized in that: The first RS485 circuit includes a thirty-second resistor, a thirty-third resistor, a thirty-fourth resistor, a thirty-fifth resistor, a thirty-sixth resistor, a thirty-seventh resistor, a thirty-eighth resistor, a thirty-ninth resistor, a fortieth resistor, a forty-first resistor, a forty-second resistor, a first RS485 transceiver, a second transistor, a first TVS transient suppression diode, and a thirty-third capacitor; One side of the thirty-second resistor is connected to the RX pin of the first RS485 transceiver, and the other side of the thirty-second resistor is connected to the PA3 pin of the single-chip microcomputer; One side of the thirty-third resistor is connected to the TX pin of the first RS485 transceiver, and the other side of the thirty-third resistor is connected to the PA2 pin of the single-chip microcomputer; One side of the thirty-fourth resistor is connected to the RX pin of the first RS485 transceiver, and the other side of the thirty-fourth resistor is connected to a power supply; One side of the thirty-fifth resistor is connected to the TX pin of the first RS485 transceiver, and the other side of the thirty-fifth resistor is connected to a power supply; One side of the thirty-sixth resistor is connected to the TX pin of the first RS485 transceiver, and the other side of the thirty-sixth resistor is connected to the base of the second transistor; One side of the thirty-seventh resistor is connected to the base of the second transistor, and the other side of the thirty-seventh resistor is connected to the emitter of the second transistor and to the ground; One side of the thirty-eighth resistor is connected to the collector of the second transistor, the RE pin of the first RS485 transceiver, and the TE pin of the first RS485 transceiver, respectively, and the other side of the thirty-eighth resistor is connected to the VCC pin of the first RS485 transceiver and to a power supply; One side of the thirty-third capacitor is connected to a power supply, and the other side of the thirty-third capacitor is connected to a ground; One side of the thirty-ninth resistor is connected to the A pin of the RS485 transceiver, and the other side of the thirty-ninth resistor is connected to one side of the forty-first resistor and one side of the forty-second resistor respectively; One side of the 40th resistor is connected to the B pin of the RS485 transceiver, and the other side of the 40th resistor is respectively connected to the other side of the 42nd resistor and one side of the 43rd resistor; The other side of the 40th resistor is connected to the power supply, and the other side of the 43rd resistor is grounded; One side of the first TVS transient suppression diode is connected to one side of the forty-second resistor, and the other side of the first TVS transient suppression diode is connected to the other side of the forty-second resistor.

9. The detection circuit for a PCBA board according to claim 7, characterized in that: The second RS485 circuit includes a forty-third resistor, a forty-fourth resistor, a forty-fifth resistor, a forty-sixth resistor, a forty-seventh resistor, a forty-eighth resistor, a forty-ninth resistor, a fiftieth resistor, a fifty-first resistor, a fifty-second resistor, a fifty-third resistor, a second RS485 transceiver, a third transistor, a second TVS transient suppression diode, and a thirty-fourth capacitor; One side of the forty-third resistor is connected to the RX pin of the second RS485 transceiver, and the other side of the forty-third resistor is connected to the other side of the seventh resistor; One side of the forty-fourth resistor is connected to the TX pin of the second RS485 transceiver, and the other side of the forty-fourth resistor is connected to the other side of the eighth resistor; One side of the forty-fifth resistor is connected to the RX pin of the second RS485 transceiver, and the other side of the forty-fifth resistor is connected to a power supply; One side of the forty-sixth resistor is connected to the TX pin of the second RS485 transceiver, and the other side of the forty-sixth resistor is connected to a power supply; One side of the forty-seventh resistor is connected to the TX pin of the second RS485 transceiver, and the other side of the forty-seventh resistor is connected to the base of the third transistor; One side of the forty-eighth resistor is connected to the base of the second transistor, and the other side of the forty-eighth resistor is connected to the emitter of the third transistor and is also connected to the ground; One side of the 49th resistor is respectively connected to the collector of the third transistor, the RE pin of the second RS485 transceiver, and the TE pin of the second RS485 transceiver, and the other side of the 49th resistor is connected to the VCC pin of the second RS485 transceiver and to a power supply; One side of the thirty-fourth capacitor is connected to a power supply, and the other side of the thirty-fourth capacitor is connected to a ground; One side of the 50th resistor is connected to the A pin of the RS485 transceiver, and the other side of the 50th resistor is respectively connected to one side of the 52nd resistor and one side of the 53rd resistor; One side of the fifty-first resistor is connected to the B pin of the RS485 transceiver, and the other side of the fifty-first resistor is respectively connected to the other side of the fifty-third resistor and one side of the fifty-fourth resistor; The other side of the fifty-first resistor is connected to a power supply, and the other side of the fifty-second resistor is grounded; One side of the second TVS transient suppression diode is connected to one side of the fifty-third resistor, and the other side of the second TVS transient suppression diode is connected to the other side of the fifty-third resistor.

10. The detection circuit for a PCBA board according to claim 7, characterized in that: The USB to TTL circuit includes a fifty-fifth resistor, a fifty-sixth resistor, a fifty-seventh resistor, a fifty-eighth resistor, a fifty-ninth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a sixtieth resistor, a seven ... capacitor, a thirty-fifth capacitor, a thirty-sixth capacitor, a thirty-seventh capacitor, a thirty-eighth capacitor, a thirty-ninth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a fortieth capacitor, a first USB to serial port chip, a second USB to serial port chip, a third USB to serial port chip, a first passive crystal oscillator, a second passive crystal oscillator, a third passive crystal oscillator, a USB transfer interface, a first copper core inductor, and a second copper core inductor; One side of the fifty-fifth resistor is connected to the UD+ pin of the first USB-to-serial port chip, and one side of the fifty-sixth resistor is connected to the UD- pin of the first USB-to-serial port chip; One side of the fifty-seventh resistor is connected to a power supply, and the other side of the fifty-seventh resistor is connected to the other side of the fifty-sixth resistor; One side of the thirty-fifth capacitor is connected to the ground, and the other side of the thirty-fifth capacitor is connected to the V3 pin of the first USB-to-serial port chip and is also connected to a power supply; One side of the fifty-eighth resistor is connected to the XI pin of the first USB-to-serial port chip, and the other side of the fifty-eighth resistor is connected to the XO pin of the first USB-to-serial port chip; One side of the thirty-sixth capacitor is connected to the XI pin of the first USB-to-serial port chip, and the other side of the thirty-sixth capacitor is connected to the second pin of the first passive crystal oscillator and is also connected to ground; One side of the thirty-seventh capacitor is connected to the XO pin of the first USB-to-serial port chip, and the other side of the thirty-seventh capacitor is connected to the fourth pin of the first passive crystal oscillator and is also connected to ground; The third pin of the first passive crystal oscillator is connected to the XI pin of the first USB-to-serial port chip, and the first pin of the first passive crystal oscillator is connected to the XO pin of the first USB-to-serial port chip; One side of the thirty-eighth capacitor is connected to the VCC pin of the first USB-to-serial port chip, and the other side of the thirty-eighth capacitor is connected to the ground; One side of the fifty-ninth resistor is connected to the VCC pin of the first USB-to-serial port chip, and the other side of the fifty-ninth resistor is connected to a power supply; The TXD pin of the first USB-to-serial port chip is connected to the RXD pin of the first USB-to-serial port chip through the sixtieth resistor, and the GND pin of the first USB-to-serial port chip is connected to the ground; One side of the sixty-first resistor is connected to the UD+ pin of the second USB-to-serial port chip, and one side of the sixty-second resistor is connected to the UD- pin of the second USB-to-serial port chip; One side of the sixty-third resistor is connected to a power supply, and the other side of the sixty-third resistor is connected to the other side of the sixty-second resistor; One side of the thirty-ninth capacitor is connected to the ground, and the other side of the thirty-ninth capacitor is connected to the V3 pin of the second USB-to-serial port chip and is also connected to a power supply; One side of the sixty-fourth resistor is connected to the XI pin of the second USB-to-serial port chip, and the other side of the sixty-fourth resistor is connected to the XO pin of the second USB-to-serial port chip; One side of the 40th capacitor is connected to the XI pin of the second USB-to-serial port chip, and the other side of the 40th capacitor is connected to the second pin of the second passive crystal oscillator and is also connected to ground; One side of the forty-first capacitor is connected to the XO pin of the second USB-to-serial port chip, and the other side of the forty-first capacitor is connected to the fourth pin of the second passive crystal oscillator and is also connected to ground; The third pin of the second passive crystal oscillator is connected to the XI pin of the second USB-to-serial port chip, and the first pin of the second passive crystal oscillator is connected to the XO pin of the second USB-to-serial port chip; One side of the forty-second capacitor is connected to the VCC pin of the second USB-to-serial port chip, and the other side of the forty-second capacitor is connected to the ground; One side of the sixty-fifth resistor is connected to the VCC pin of the second USB-to-serial port chip, and the other side of the sixty-fifth resistor is connected to the power supply; The TXD pin of the second USB-to-serial port chip is connected to the RXD pin of the second USB-to-serial port chip through the sixty-sixth resistor, and the GND pin of the second USB-to-serial port chip is connected to the ground; One side of the sixty-first resistor is connected to one side of the sixty-sixth resistor through the sixty-seventh resistor; The other side of the sixty-first resistor is connected to the other side of the sixty-sixth resistor through the sixty-eighth resistor; One side of the sixty-ninth resistor is connected to the UD+ pin of the third USB-to-serial port chip, and one side of the seventieth resistor is connected to the UD- pin of the third USB-to-serial port chip; One side of the seventy-first resistor is connected to a power supply, and the other side of the seventy-first resistor is connected to the other side of the seventieth resistor; One side of the forty-third capacitor is connected to the ground, and the other side of the forty-third capacitor is connected to the V3 pin of the third USB-to-serial port chip and is also connected to a power supply; One side of the seventy-second resistor is connected to the XI pin of the third USB-to-serial port chip, and the other side of the seventy-second resistor is connected to the XO pin of the third USB-to-serial port chip; One side of the forty-fourth capacitor is connected to the XI pin of the third USB-to-serial port chip, and the other side of the forty-fourth capacitor is connected to the second pin of the third passive crystal oscillator and is also connected to ground; One side of the forty-fifth capacitor is connected to the XO pin of the third USB-to-serial port chip, and the other side of the forty-fifth capacitor is connected to the fourth pin of the third passive crystal oscillator and is also connected to ground; The third pin of the third passive crystal oscillator is connected to the XI pin of the third USB-to-serial port chip, and the first pin of the third passive crystal oscillator is connected to the XO pin of the third USB-to-serial port chip; One side of the forty-sixth capacitor is connected to the VCC pin of the third USB-to-serial port chip, and the other side of the forty-sixth capacitor is connected to the ground; One side of the seventy-third resistor is connected to the VCC pin of the third USB-to-serial port chip, and the other side of the seventy-third resistor is connected to a power supply; The TXD pin of the third USB-to-serial port chip is connected to the RXD pin of the third USB-to-serial port chip via a seventy-fourth resistor; One side of the first copper core inductor is connected to a power supply, and the other side of the first copper core inductor is connected to a USB_OTG_VBUS1 pin; One side of the second copper core inductor is connected to the first pin of the USB adapter, and the other side of the second copper core inductor is connected to the power supply; One side of the seventy-fifth resistor is connected to the second pin of the USB adapter, and the other side of the seventy-fifth resistor is connected to the USB3_HOST_DN pin; One side of the seventy-sixth resistor is connected to the third pin of the USB adapter, and the other side of the seventy-sixth resistor is connected to the USB3_HOST_DP pin; One side of the seventy-seventh resistor is connected to the fifth pin of the USB adapter, and the other side of the seventy-seventh resistor is connected to the USB3_SSRXN pin; One side of the seventy-eighth resistor is connected to the sixth pin of the USB adapter, and the other side of the seventy-eighth resistor is connected to the USB3_SSRXP pin; One side of the forty-seventh capacitor is connected to the eighth pin of the USB adapter, and the other side of the forty-seventh capacitor is connected to the USB3_SSTXN pin; One side of the forty-eighth capacitor is connected to the ninth pin of the USB adapter, and the other side of the forty-eighth capacitor is connected to the USB3_SSTXP pin; One side of the forty-ninth capacitor is respectively connected to the tenth pin of the USB adapter and the eleventh pin of the USB adapter, and the other side of the forty-ninth capacitor is respectively connected to the fourth pin of the USB adapter and the seventh pin of the USB adapter, and is connected to the ground.

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