Alternating current and direct current transmitter device

Abstract

The utility model relates to an AC / DC current transmitter device, which comprises an outer shell formed by buckling an upper shell and a lower shell up and down, a circuit board is arranged in the upper shell, and an analog quantity signal output terminal, a power supply input terminal, a first current signal input terminal and a second current signal input terminal are arranged on the circuit board. The analog quantity signal output terminal and the power supply input terminal are arranged at the left part of the circuit board; the first current signal input terminal and the second current signal input terminal are arranged at the right part of the circuit board; a dial switch is arranged at the top of the circuit board; the circuit board is also provided with a current acquisition module, and a current signal is converted into a voltage signal through the current acquisition module and is transmitted to the current signal conditioning circuit. The device supports measurement of direct current or alternating current at the same time, an input signal acquisition mode can be changed through the dial switch, and the measuring range can be changed according to different current magnitudes.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical measurement and monitoring, in particular to an AC and DC current transmitter device. Background Art

[0002] A current transmitter is a measuring instrument that converts the measured current into a linearly proportional DC current or voltage output. It is widely used in electrical measurement, automatic control, and dispatching systems in sectors such as electricity, petroleum, coal, metallurgy, railways, and municipal administration. Currently, most current transmitters have the following defects:

[0003] (1) Most current transmitters can only measure DC or AC current and are not compatible with both DC and AC scenarios;

[0004] (2) Most current transmitters have fixed ranges, and users cannot adjust the range for different current sizes;

[0005] (3) Most current transmitters have a fixed output signal mode, and users cannot adjust the output signal mode of the transmitter according to the subsequent receiving device. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide an AC / DC current transmitter device to solve the above-mentioned problems.

[0007] The purpose of this utility model is achieved in this way:

[0008] An AC / DC current transmitter device includes an outer shell composed of an upper shell and a lower shell with upper and lower buckles. The upper shell is provided with a circuit board, and the circuit board is provided with an analog signal output terminal, a power input terminal, a first current signal input terminal, and a second current signal input terminal. The analog signal output terminal and the power input terminal are arranged on the left side of the circuit board, and the first current signal input terminal and the second current signal input terminal are arranged on the right side of the circuit board. A dip switch is provided on the top of the circuit board.

[0009] The circuit board is further provided with a current acquisition module, which is arranged on the left side of the first current signal input terminal and the second current signal input terminal; the current signal is converted into a voltage signal by the current acquisition module and transmitted to the current signal conditioning circuit;

[0010] The circuit board is also provided with a DC / DC conversion circuit, a single-chip power supply circuit, an analog output circuit, a current acquisition and signal conditioning circuit, a single-chip circuit and a dip switch circuit. The power supply circuit is connected to the current signal conditioning circuit, the current acquisition circuit is connected to the current signal conditioning circuit, the current acquisition circuit collects the current signal through the current acquisition module, the current signal conditioning circuit is connected to the single-chip circuit, the dip switch circuit is connected to the single-chip circuit, and the single-chip circuit is connected to the analog output circuit. The analog output circuit includes a voltage analog output circuit and a current analog output circuit.

[0011] The voltage analog output circuit includes an optical coupler U6, a chip U8, and a chip U4. The optical coupler U6 isolates and transmits the PWM wave signal, the chip U8 performs waveform shaping on the PWM wave signal, and the chip U4 outputs a voltage signal of corresponding magnitude according to the duty cycle of the PWM wave. One side of the optical coupler U6 is connected to the chip U8 through a resistor R28. The resistor R28 is respectively connected to the voltage regulator D3 and the resistor R26. The resistors R26, R28, and the voltage regulator D3 perform amplitude stabilization on the isolated PWM wave signal. The chip U8 is connected to the chip U4.

[0012] The current analog output circuit includes an optocoupler U9, a chip U10, and a chip U7. The optocoupler U9 isolates and transmits the PWM wave signal. One side of the optocoupler U6 is connected to the chip U10 through a resistor R33. The resistor R33 is respectively connected to the voltage regulator D11 and the resistor R30. The resistors R30, R33, and the voltage regulator D11 stabilize the amplitude of the isolated PWM wave signal. The chip U10 performs a waveform trimming function on the PWM wave signal. The chip U10 is connected to the chip U7. The chip U7 is connected to the source S of the MOS tube Q1. The gate G of the MOS tube Q1 is respectively connected to the voltage regulator D14, the resistor R35, and the capacitor C53. The chip U7, the MOS tube Q1, the voltage regulator D14, the resistor R35, and the capacitor C53 constitute a current output circuit, which outputs a current signal of corresponding magnitude according to the duty cycle of the PWM wave.

[0013] Furthermore, a pin of the chip U4 in the voltage analog output circuit is connected to the capacitor C41 and the inductor L6 respectively, and the inductor L6 is connected to the capacitor C45, the diode D13 and the TVS tube D12 in parallel. The capacitors C41, C45 and the inductor L6 play the role of filtering out high-frequency interference signals, and the diode D13 and the TVS tube D12 play the role of clamping.

[0014] Furthermore, the drain D of the MOS tube Q1 in the current analog output circuit is respectively connected to the capacitor C54 and the diode D16, the diode D16 is respectively connected to the capacitor C55 and the inductor L5, and the inductor L5 is respectively connected to the capacitor C57, the diode D17 and the TVS tube D18. The capacitors C54, C55, C57 and the inductor L5 play a role in filtering out high-frequency interference signals, the diode D16 has an anti-reverse connection function, and the diode D17 and the TVS tube D18 play a clamping role.

[0015] Furthermore, the power supply circuit is a DC / DC conversion circuit: a power supply circuit with a DC 9~36V input, including a power supply chip IC2, a varistor RV1, a TVS tube D7, an inductor L1, an inductor L3 and a capacitor C8 to constitute power input EMC protection, the power supply chip IC2 is connected to capacitors C33, C34 and C35 in parallel, capacitors C33, C34 and C35 act as filters, capacitor C34 is connected to the varistor RV1, capacitor C8 and TVS tube D7 in parallel, a fuse PT2 is provided between the varistor RV1 and the capacitor C8 for current limiting protection, one end of the capacitor C8 is connected to one end of the TVS tube D7 through the inductor L1 and the diode D4, the diode D4 acts as an anti-reverse connection, and the other end of the capacitor C8 is connected to the other end of the TVS tube D7 through the inductor L3; the power supply chip IC2 realizes the conversion of the output DC5V.

[0016] Furthermore, the single-chip microcomputer power supply circuit includes a chip IC3, a transformer T1, and a chip U11. Chip IC3 is connected to transformer T1. IC3 converts 5V power into AC power, which is isolated and converted by transformer T1. Pin 4 of transformer T1 is connected to diode D8, and pin 6 of transformer T1 is connected to diode D5. Diode D8 and diode D5 are connected to a TVS diode D2, capacitor C29, resistor R20, and capacitor C1 in parallel. Capacitor C1 is connected to the input of chip U11, and the output of chip U11 is connected to a TVS diode D23, capacitors C30, and C32 in parallel. Diodes D5 and D8 act as a rectifier, TVS diode D2 acts as a clamp, and capacitors C29 and C1 act as a filter. Chip U11 acts as a voltage converter, converting 6V to 5V. TVS diode D23 acts as a clamp, and capacitors C30 and C32 act as a filter.

[0017] Furthermore, the analog output circuit power supply includes a chip IC4, which is connected to a transformer T2. IC4 inverts the 5V power supply into an AC power supply and performs isolation conversion through the transformer T2; the transformer T2 is connected to diodes D9, D10, D19, and D20 connected in series, and the diodes D9, D10, D19, and D20 are connected in series and then connected to a TVS tube D22 and a capacitor C37 in parallel; the diodes D9, D10, D19, and D20 act as a rectifier, rectifying the AC voltage to DC24V, the TVS tube D22 acts as a clamp, and the capacitor C37 acts as a filter.

[0018] Furthermore, the current acquisition and signal conditioning circuit includes a chip U3, a chip U1B and a differential sampling circuit. The chip U3 performs isolated sampling on the input current and outputs a voltage signal waveform corresponding to the current waveform. The chip U1B is connected to the resistor R4 and the resistor R8 to form a sampling reference signal. The differential sampling circuit includes resistors R10, R11, R12, R13, R15, R17, a diode D1, resistors R7, R34, a capacitor C7 and a capacitor C13. The resistor R13 is connected to the resistors R 17, R11, diode D1 and resistor R7, resistor R17 is connected to resistor R12, resistor R11 is connected to resistor R15, resistors R12 and R15 are respectively connected to resistor R10, one end of diode D1 is connected to resistor R7, resistor R7 is connected to capacitor C7 and capacitor C13, capacitor C13 is connected to resistor R34, and resistor R34 is connected to the other end of diode D1; diode D1 clamps the sampling signal, and resistors R7, R34, capacitors C7 and C13 filter the sampling signal.

[0019] Furthermore, the single-chip microcomputer circuit includes a chip IC1, an indicator light circuit, a temperature measurement circuit, an interface J5 and an interface J6. The indicator light circuit includes an indicator light LED1, resistors R6 and R9. The temperature measurement circuit includes a resistor R14, PT1, a capacitor C16 and a chip U1A. The chip IC1 calculates the current sampling signal and can calculate the DC current and AC current respectively. The interface J5 is the program burning port of the chip IC1, and the interface J6 is the communication interface of the chip IC1.

[0020] Furthermore, the dip switch circuit includes a dip switch SW1, a chip U5 and a chip U6. One side pin of the dip switch SW1 is grounded, and the other side pin is respectively connected to the pull-up resistors R16, R1, R40, R41, R42, R43 and R44. The chip U5 and the chip U6 play an anti-static role for the dip switch.

[0021] Furthermore, an openable sliding cover is provided on the top surface of the upper shell, and the position of the sliding cover corresponds to the position of the dip switch below. The dip switch on the circuit board can be exposed by opening the sliding cover on the upper shell.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] The utility model provides an AC / DC current transmitter device, which supports measuring DC or AC at the same time. The user can change the input signal acquisition mode through the dip switch; the user can change the range according to different current sizes through the dip switch; the user can adjust the output signal mode of the transmitter according to the subsequent acquisition equipment through the dip switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of the present utility model.

[0025] Figure 2 This is a principle block diagram of the utility model.

[0026] Figure 3 This is a circuit schematic diagram of the DC / DC conversion circuit of the present utility model.

[0027] Figure 4 This is a circuit schematic diagram of the single-chip microcomputer power supply circuit of the utility model.

[0028] Figure 5 This is a circuit schematic diagram of the analog output circuit power supply of the utility model.

[0029] Figure 6 This is a circuit schematic diagram of the current acquisition and signal conditioning circuit of the utility model.

[0030] Figure 7 This is a circuit principle diagram of the single chip microcomputer circuit of the present utility model.

[0031] Figure 8 This is a circuit principle diagram of the DIP switch circuit of the present utility model.

[0032] Figure 9 This is a circuit schematic diagram of the voltage analog output circuit of the present utility model.

[0033] Figure 10 This is a circuit schematic diagram of the current analog output circuit of the present utility model.

[0034] in:

[0035] Upper housing 1, analog signal output terminal 2, power input terminal 3, circuit board 4, lower housing 5, slide cover 6, DIP switch 7, first current signal input terminal 8, second current signal input terminal 9, current acquisition module 10, locking piece 11. DETAILED DESCRIPTION

[0036] To better understand the technical solution of the present invention, the following detailed description is provided with reference to the relevant illustrations. It should be understood that the following specific embodiments are not intended to limit the specific implementation of the technical solution of the present invention; they are merely examples of possible implementations of the technical solution of the present invention. It should be noted that the description herein of the positional relationships of the various components, such as component A being located above component B, is based on the relative positions of the components in the illustrations and is not intended to limit the actual positional relationships of the components. Example 1

[0037] See also Figures 1-10 , Figure 1 A schematic structural diagram of the present invention is provided. As shown in the figure, the present invention relates to an AC / DC current transmitter device comprising an outer shell consisting of an upper shell 1 and a lower shell 5, with upper and lower snaps. A circuit board 4 is disposed within the upper shell 1. The circuit board 4 is provided with analog signal output terminals 2, power input terminals 3, first current signal input terminals 8, and second current signal input terminals 9. The analog signal output terminals 2 and power input terminals 3 are located on the left side of the circuit board 4, while the first current signal input terminals 8 and second current signal input terminals 9 are located on the right side of the circuit board 4. A dip switch 7 is disposed on the top of the circuit board 4.

[0038] The top surface of the upper housing 1 is provided with an openable slide cover 6, the position of the slide cover 6 corresponds to the position of the dip switch 7 below. By opening the slide cover 6 on the upper housing 1, the dip switch 7 on the circuit board 4 can be exposed;

[0039] The circuit board 4 is also provided with a current acquisition module 10, which is arranged on the left side of the first current signal input terminal 8 and the second current signal input terminal 9; the current signal is converted into a voltage signal by the current acquisition module 10 and transmitted to the current signal conditioning circuit. The chip on the circuit board 4 can set different ranges and analog signal output modes of the current transmitter by detecting the state of the dip switch 7.

[0040] A locking member 11 is provided at the bottom of the lower housing 5 .

[0041] join Figure 2 , Figure 2This is a block diagram of the principle of the present invention. As shown in the figure, the circuit board 4 is also equipped with a DC / DC conversion circuit, a single-chip microcomputer power supply circuit, an analog output circuit, a current acquisition and signal conditioning circuit, a single-chip microcomputer circuit, and a DIP switch circuit. The power supply circuit is connected to the current signal conditioning circuit, the current acquisition circuit is connected to the current signal conditioning circuit, the current acquisition circuit collects current signals through a current acquisition module, the current signal conditioning circuit is connected to the single-chip microcomputer circuit, the DIP switch circuit is connected to the single-chip microcomputer circuit, and the single-chip microcomputer circuit is connected to the analog output circuit. The analog output circuit includes a voltage analog output circuit and a current analog output circuit.

[0042] The power supply circuit on circuit board 4 steps down the input power and stabilizes it to the voltage required by the current transmitter. The analog output circuit on circuit board 4 converts the current signal into a corresponding analog output signal, which is ultimately transmitted through analog signal output terminal 2. The current signal is converted into a voltage signal by current acquisition module 10 and transmitted to the current signal conditioning circuit. The chip on circuit board 4 detects the state of DIP switch 7 to set the current transmitter's different ranges and analog signal output modes.

[0043] join Figure 3 , Figure 3 This is a schematic diagram of the DC / DC converter circuit of the present invention. As shown, the power supply circuit, i.e., the DC / DC converter circuit, comprises a power supply circuit with a DC 9-36V input, including a power supply chip IC2, a varistor RV1, a TVS diode D7, an inductor L1, an inductor L3, and a capacitor C8 to provide EMC protection for the power supply input. The power supply chip IC2 is connected to capacitors C33, C34, and C35 in parallel, which act as filters. Capacitor C34 is connected to the varistor RV1, capacitor C8, and TVS diode D7 in parallel. A fuse PT2 is provided between the varistor RV1 and capacitor C8 for current limiting protection. One end of capacitor C8 is connected to one end of TVS diode D7 via inductor L1 and diode D4, which acts as a reverse polarity protection device. The other end of capacitor C8 is connected to the other end of TVS diode D7 via inductor L3. The power supply chip IC2 achieves DC 5V output conversion.

[0044] join Figure 4 , Figure 4This is the schematic diagram of the microcontroller power supply circuit of the present utility model. As shown in the figure, the microcontroller power supply circuit includes chip IC3, transformer T1, and chip U11. Chip IC3 is connected to transformer T1. IC3 converts 5V power into AC power, which is isolated and converted by transformer T1. Pin 4 of transformer T1 is connected to diode D8, and pin 6 of transformer T1 is connected to diode D5. Diode D8 and diode D5 are connected to a parallel TVS diode D2, capacitor C29, resistor R20, and capacitor C1. Capacitor C1 is connected to the input of chip U11. The output of chip U11 is connected to a parallel TVS diode D23, capacitors C30, and C32. Diodes D5 and D8 perform rectification, TVS diode D2 acts as a clamp, and capacitors C29 and C1 act as filters. Chip U11 performs voltage conversion, converting 6V to 5V. TVS diode D23 acts as a clamp, and capacitors C30 and C32 act as filters.

[0045] join Figure 5 , Figure 5 This is the schematic diagram of the analog output circuit power supply of the present invention. As shown, the analog output circuit power supply includes chip IC4, which is connected to transformer T2. IC4 converts 5V power into AC power, which is then isolated and converted by transformer T2. Transformer T2 is connected to diodes D9, D10, D19, and D20, which are connected in series. Diodes D9, D10, D19, and D20 are then connected in parallel to a TVS diode D22 and capacitor C37. Diodes D9, D10, D19, and D20 act as a rectifier, converting the AC voltage to 24V DC. TVS diode D22 acts as a clamp, and capacitor C37 provides filtering.

[0046] join Figure 6 , Figure 6This is a schematic diagram of the current acquisition and signal conditioning circuit of the present invention. As shown in the figure, the current acquisition and signal conditioning circuit includes chip U3, chip U1B, and a differential sampling circuit. Chip U3 isolates and samples the input current and outputs a voltage signal waveform corresponding to the current waveform. Chip U1B is connected to resistors R4 and R8 to form a sampling reference signal. The differential sampling circuit includes resistors R10, R11, R12, R13, R15, R17, diode D1, resistors R7, R34, capacitor C7, and capacitor C13. Resistor R13 is respectively connected to resistors R17, R11, diode D1, and resistor R7. Resistor R17 is connected to resistor R12. Resistor R11 is connected to resistor R15. Resistor R12 and resistor R15 are respectively connected to resistor R10. One end of diode D1 is connected to resistor R7. Resistor R7 is connected to capacitor C7 and capacitor C13. Capacitor C13 is connected to resistor R34. Resistor R34 is connected to the other end of diode D1. The diode D1 clamps the sampling signal, and the resistors R7, R34, and the capacitors C7 and C13 filter the sampling signal.

[0047] join Figure 7 , Figure 7 This is the schematic diagram of the microcontroller circuit of the present invention. As shown, the microcontroller circuit includes chip IC1, an indicator light circuit, a temperature measurement circuit, interfaces J5, and J6. The indicator light circuit includes LED1, resistors R6 and R9, and the temperature measurement circuit includes resistor R14, PT1, capacitor C16, and chip U1A. Chip IC1 calculates the DC and AC currents based on the current sampling signal. Interface J5 is the program burning port for chip IC1, and interface J6 is the communication interface for chip IC1.

[0048] join Figure 8 , Figure 8 This is a schematic diagram of the DIP switch circuit of the present invention. As shown, the DIP switch circuit includes a DIP switch SW1, chips U5, and U6. One pin of DIP switch SW1 is grounded, while the other pins are connected to pull-up resistors R16, R1, R40, R41, R42, R43, and R44, respectively. Chips U5 and U6 act as anti-static devices for the DIP switch.

[0049] join Figure 9 , Figure 9This is a schematic diagram of the voltage analog output circuit of the present invention. As shown in the figure, the voltage analog output circuit includes an optocoupler U6, a chip U8, and a chip U4. The optocoupler U6 isolates and transmits the PWM wave signal, the chip U8 performs waveform shaping on the PWM wave signal, and the chip U4 outputs a voltage signal of corresponding magnitude according to the duty cycle of the PWM wave. One side of the optocoupler U6 is connected to the chip U8 through a resistor R28. The resistor R28 is respectively connected to the voltage regulator D3 and the resistor R26. The resistors R26, R28, and the voltage regulator D3 perform amplitude stabilization on the isolated PWM wave signal. The chip U8 is connected to the chip U4. One pin of the chip U4 is respectively connected to the capacitor C41 and the inductor L6. The inductor L6 is connected to the parallel capacitor C45, the diode D13, and the TVS diode D12. The capacitors C41, C45, and the inductor L6 filter out high-frequency interference signals, and the diode D13 and the TVS diode D12 act as clamps.

[0050] join Figure 10 , Figure 10 This is the circuit principle diagram of the current analog output circuit of the present invention. As shown in the figure, the current analog output circuit includes an optocoupler U9, a chip U10, and a chip U7. The optocoupler U9 isolates and transmits the PWM wave signal. One side of the optocoupler U6 is connected to the chip U10 through a resistor R33. The resistor R33 is respectively connected to the voltage regulator D11 and the resistor R30. The resistors R30, R33, and the voltage regulator D11 perform amplitude stabilization on the isolated PWM wave signal. The chip U10 plays a waveform shaping role on the PWM wave signal. The chip U10 is connected to the chip U7. The chip U7 is connected to the source S of the MOS tube Q1. The gate G of the MOS tube Q1 is respectively connected to the voltage regulator D14, the resistor R35, and the resistor R36. Capacitor C53, chip U7, MOS transistor Q1, voltage regulator diode D14, resistor R35 and capacitor C53 form a current output circuit, which outputs a current signal of corresponding magnitude according to the duty cycle of the PWM wave; the drain D of MOS transistor Q1 is respectively connected to capacitor C54 and diode D16, diode D16 is respectively connected to capacitor C55 and inductor L5, inductor L5 is respectively connected to capacitor C57, diode D17 and TVS diode D18. Capacitors C54, C55, C57 and inductor L5 filter out high-frequency interference signals, diode D16 is used to prevent reverse connection, and diode D17 and TVS diode D18 act as clamps.

[0051] Working principle:

[0052] The utility model relates to an AC / DC current transmitter device, which comprises a current acquisition module, a current signal conditioning circuit, and an analog output circuit which are centrally installed in upper and lower shells. The device can measure DC or AC, and the input signal acquisition mode and the output signal mode can be changed by a dial switch.

[0053] The installation method is as follows:

[0054] Solder terminals 2, 3, 8, 9, and the current acquisition module 10 to the circuit board 4, install the circuit board 4 into the lower shell 5, then connect the upper shell 1 and the lower shell 5 through snaps, install the circuit board 4 in the upper shell 1 and the lower shell 5, and finally install the locking piece 11 into the bottom of the lower shell 5. By opening the sliding cover 6 on the upper shell 1, the dip switch 7 on the circuit board 4 can be exposed.

[0055] Terminal 3 is the power input terminal for the current transmitter. The power circuit on circuit board 4 steps down the input power and stabilizes it to the voltage required by the current transmitter. Terminal 2 is the analog signal output terminal. The analog output circuit on circuit board 4 converts the current signal into a corresponding analog output signal based on the current signal, which is ultimately transmitted externally through terminal 2. Terminals 8 and 9 are the current signal input terminals. The current signal is converted into a voltage signal by the current acquisition module 10 and transmitted to the current signal conditioning circuit. The chip on circuit board 4 can set the current transmitter's different ranges and analog signal output modes by detecting the state of the DIP switch 7.

[0056] The above are only specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. Any technical solution formed by equivalent transformation or equivalent replacement shall fall within the scope of protection of the present invention.

Claims

1. An AC / DC current transmitter device, characterized in that: The invention comprises an outer shell composed of an upper shell (1) and a lower shell (5) with upper and lower buckles, wherein a circuit board (4) is provided in the upper shell (1), and an analog signal output terminal (2), a power input terminal (3), a first current signal input terminal (8) and a second current signal input terminal (9) are provided on the circuit board (4); the analog signal output terminal (2) and the power input terminal (3) are arranged on the left side of the circuit board (4), and the first current signal input terminal (8) and the second current signal input terminal (9) are arranged on the right side of the circuit board (4); a dial switch (7) is provided on the top of the circuit board (4); The circuit board (4) is further provided with a current acquisition module (10), which is arranged on the left side of the first current signal input terminal (8) and the second current signal input terminal (9); the current signal is converted into a voltage signal by the current acquisition module (10) and transmitted to the current signal conditioning circuit; The circuit board (4) is also provided with a DC / DC conversion circuit, a single-chip power supply circuit, an analog output circuit, a current acquisition and signal conditioning circuit, a single-chip circuit and a dial switch circuit, the power supply circuit is connected to the current signal conditioning circuit, the current acquisition circuit is connected to the current signal conditioning circuit, the current acquisition circuit acquires the current signal through the current acquisition module, the current signal conditioning circuit is connected to the single-chip circuit, the dial switch circuit is connected to the single-chip circuit, the single-chip circuit is connected to the analog output circuit, and the analog output circuit includes a voltage analog output circuit and a current analog output circuit; The voltage analog output circuit includes an optical coupler U6, a chip U8, and a chip U4. The optical coupler U6 isolates and transmits the PWM wave signal, the chip U8 performs waveform shaping on the PWM wave signal, and the chip U4 outputs a voltage signal of corresponding magnitude according to the duty cycle of the PWM wave. One side of the optical coupler U6 is connected to the chip U8 through a resistor R28. The resistor R28 is respectively connected to the voltage regulator D3 and the resistor R26. The resistors R26, R28, and the voltage regulator D3 perform amplitude stabilization on the isolated PWM wave signal. The chip U8 is connected to the chip U4. The current analog output circuit includes an optocoupler U9, a chip U10, and a chip U7. The optocoupler U9 isolates and transmits the PWM wave signal. One side of the optocoupler U6 is connected to the chip U10 through a resistor R33. The resistor R33 is respectively connected to the voltage regulator D11 and the resistor R30. The resistors R30, R33, and the voltage regulator D11 stabilize the amplitude of the isolated PWM wave signal. The chip U10 performs a waveform trimming function on the PWM wave signal. The chip U10 is connected to the chip U7. The chip U7 is connected to the source S of the MOS tube Q1. The gate G of the MOS tube Q1 is respectively connected to the voltage regulator D14, the resistor R35, and the capacitor C53. The chip U7, the MOS tube Q1, the voltage regulator D14, the resistor R35, and the capacitor C53 constitute a current output circuit, which outputs a current signal of corresponding magnitude according to the duty cycle of the PWM wave.

2. The AC / DC current transmitter device according to claim 1, characterized in that: A pin of the chip U4 in the voltage analog output circuit is connected to the capacitor C41 and the inductor L6 respectively. The inductor L6 is connected to the capacitor C45, the diode D13 and the TVS tube D12 in parallel. The capacitors C41, C45 and the inductor L6 play the role of filtering out high-frequency interference signals, and the diode D13 and the TVS tube D12 play the role of clamping.

3. The AC / DC current transmitter device according to claim 1, characterized in that: The drain D of the MOS tube Q1 in the current analog output circuit is respectively connected to the capacitor C54 and the diode D16, the diode D16 is respectively connected to the capacitor C55 and the inductor L5, and the inductor L5 is respectively connected to the capacitor C57, the diode D17 and the TVS tube D18. The capacitors C54, C55, C57 and the inductor L5 play a role in filtering out high-frequency interference signals, the diode D16 has a reverse connection protection function, and the diode D17 and the TVS tube D18 play a clamping role.

4. The AC / DC current transmitter device according to claim 1, characterized in that: The power supply circuit is a DC / DC conversion circuit: a power supply circuit with a DC 9-36V input, including a power supply chip IC2, a varistor RV1, a TVS tube D7, an inductor L1, an inductor L3, and a capacitor C8 to form power input EMC protection. The power supply chip IC2 is connected to capacitors C33, C34, and C35 in parallel. Capacitors C33, C34, and C35 act as filters. Capacitor C34 is connected to the varistor RV1, capacitor C8, and TVS tube D7 in parallel. A fuse PT2 is provided between the varistor RV1 and capacitor C8 for current limiting protection. One end of the capacitor C8 is connected to one end of the TVS tube D7 via the inductor L1 and the diode D4. The diode D4 acts as a reverse connection protection. The other end of the capacitor C8 is connected to the other end of the TVS tube D7 via the inductor L3. The power supply chip IC2 realizes the conversion of the output DC5V.

5. The AC / DC current transmitter device according to claim 4, characterized in that: The single-chip microcomputer power supply circuit includes a chip IC3, a transformer T1 and a chip U11. The chip IC3 is connected to the transformer T1. IC3 inverts the 5V power supply into an AC power supply, and performs isolation conversion through the transformer T1. Pin 4 of the transformer T1 is connected to the diode D8, and pin 6 of the transformer T1 is connected to the diode D5. After the diode D8 and the diode D5 are connected, they are connected to the TVS tube D2, capacitor C29, resistor R20 and capacitor C1 in parallel. The capacitor C1 is connected to the input end of the chip U11. The output end of the chip U11 is connected to the TVS tube D23, capacitors C30 and C32 in parallel. The diodes D5 and D8 have a rectifying effect, the TVS tube D2 has a clamping effect, and the capacitors C29 and C1 have a filtering effect. The chip U11 has a voltage conversion effect, converting the 6V voltage into 5V. The TVS tube D23 has a clamping effect, and the capacitors C30 and C32 have a filtering effect.

6. The AC / DC current transmitter device according to claim 1, characterized in that: The analog output circuit power supply includes a chip IC4, which is connected to a transformer T2. IC4 inverts a 5V power supply into an AC power supply and performs isolation conversion through the transformer T2. The transformer T2 is connected to diodes D9, D10, D19, and D20 connected in series. The diodes D9, D10, D19, and D20 are connected in series and then connected to a TVS tube D22 and a capacitor C37 connected in parallel. The diodes D9, D10, D19, and D20 act as a rectifier, rectifying the AC voltage to DC24V. The TVS tube D22 acts as a clamp, and the capacitor C37 acts as a filter.

7. The AC / DC current transmitter device according to claim 1, characterized in that: The current acquisition and signal conditioning circuit includes a chip U3, a chip U1B and a differential sampling circuit. The chip U3 performs isolated sampling on the input current and outputs a voltage signal waveform corresponding to the current waveform. The chip U1B is connected to the resistor R4 and the resistor R8 to form a sampling reference signal. The differential sampling circuit includes resistors R10, R11, R12, R13, R15, R17, a diode D1, a resistor R7, R34, a capacitor C7 and a capacitor C13. The resistor R13 is respectively connected to the resistors R17, R11, the diode D1 and the resistor R7. The resistor R17 is connected to the resistor R12. The resistor R11 is connected to the resistor R15. The resistors R12 and R15 are respectively connected to the resistor R10. One end of the diode D1 is connected to the resistor R7. The resistor R7 is connected to the capacitor C7 and the capacitor C13. , capacitor C13 is connected to resistor R34, and resistor R34 is connected to the other end of diode D1; diode D1 clamps the sampling signal, and resistors R7, R34, capacitor C7 and C13 filter the sampling signal.

8. The AC / DC current transmitter device according to claim 1, characterized in that: The single-chip microcomputer circuit includes a chip IC1, an indicator light circuit, a temperature measurement circuit, an interface J5 and an interface J6. The indicator light circuit includes an indicator light LED1, resistors R6 and R9. The temperature measurement circuit includes a resistor R14, PT1, a capacitor C16 and a chip U1A. The chip IC1 calculates the current sampling signal and can calculate the DC current and AC current respectively. The interface J5 is the program burning port of the chip IC1, and the interface J6 is the communication interface of the chip IC1.

9. The AC / DC current transmitter device according to claim 1, characterized in that: The dip switch circuit includes a dip switch SW1, a chip U5 and a chip U6. One pin of the dip switch SW1 is grounded, and the other pin is connected to pull-up resistors R16, R1, R40, R41, R42, R43 and R44 respectively. Chip U5 and chip U6 play an anti-static role for the dip switch.

10. The AC / DC current transmitter device according to claim 1, characterized in that: The top surface of the upper housing (1) is provided with an openable sliding cover (6), the position of the sliding cover (6) corresponding to the position of the dial switch (7) below, and the dial switch (7) on the circuit board (4) can be exposed by opening the sliding cover (6) on the upper housing (1).

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