Shutdown detection circuit

Abstract

The invention relates to the technical field of motor control, and discloses a shutdown detection circuit comprising a control module which outputs a switching signal which switches a short circuit detection mode and an open circuit detection mode; the function switching module is respectively connected with the first power supply end, the thyristor and the control module, and is used for receiving the switching signal and switching; the short circuit detection module is respectively connected with the first power supply end, the thyristor and the control module, and the short circuit detection module regulates the input power supply voltage and then outputs the voltage; the open circuit detection module is respectively connected with the control end of the thyristor, the detection resistor and the control module, and is used for driving the thyristor to be conducted after receiving the starting signal, and collecting and outputting a detection current; and the switch module is respectively connected with the control module and the motor control circuit and is closed after receiving the turn-off signal. The problem that potential safety hazards exist due to the fact that the quality of the thyristors cannot be ensured is solved.

Description

Technical Field

[0001] The invention relates to the technical field of motor control, and in particular to a shutdown detection circuit. Background Art

[0002] With the development of science and technology, motors have been widely used, and the shutdown function of motors is related to safety issues.

[0003] The thyristor in the shutdown circuit is a key component of the shutdown function. The quality of the thyristor determines whether the shutdown function is normal. In order to ensure the quality of the thyristor, it is necessary to test the thyristor. Summary of the invention

[0004] In view of this, the present invention provides a shutdown detection circuit to solve the problem in the prior art that the quality of the thyristor cannot be ensured, resulting in potential safety hazards.

[0005] In a first aspect, the present invention provides a shutdown detection circuit, wherein the shutdown detection circuit is connected to a shutdown control circuit, wherein the shutdown control circuit comprises: a thyristor and a motor control circuit, and wherein the shutdown detection circuit comprises:

[0006] A control module, the control module is used to output a switching signal, the switching signal is used to switch between a short circuit detection mode and an open circuit detection mode;

[0007] A function switching module, the function switching module is respectively connected to the first power supply end, the first end of the thyristor and the control module, and is used to receive the switching signal and perform switching;

[0008] A short-circuit detection module, the short-circuit detection module is respectively connected to the first power supply terminal, the first end of the thyristor and the control module, and the short-circuit detection module is used for adjusting the input power supply voltage and then outputting it;

[0009] The control module is also used to receive the regulated input power supply voltage, and in the short-circuit detection mode, when it is detected that the regulated input power supply voltage is less than a first preset voltage value, confirm that the thyristor is short-circuited;

[0010] The control module is also used to output a start signal;

[0011] A circuit breaker detection module, which is connected to the control end of the thyristor, the detection resistor and the control module respectively, and is used to drive the thyristor to conduct after receiving the start signal, and collect the detection current flowing through the detection resistor and then output it;

[0012] The control module receives the detection current, and in the circuit breaking detection mode, when it is detected that the regulated input power supply voltage is greater than a second preset voltage value and the detection current is a preset current value, confirms that the thyristor is circuit broken;

[0013] The control module is also used to output a shutdown signal when a thyristor short circuit or open circuit is detected, so as to control the motor control circuit to stop running;

[0014] A switch module is connected to the control module and the motor control circuit respectively, and is used to close after receiving the shutdown signal.

[0015] In an optional implementation, the function switching module includes:

[0016] A first switch tube, wherein a control end of the first switch tube is connected to the control module, a first end of the first switch tube is connected to the first power supply end, and a second end of the first switch tube is connected to the first end of the first diode, wherein the first switch tube is used to supply power to the short circuit detection module in a short circuit detection mode;

[0017] A second switch tube, wherein the first end of the second switch tube is connected to the shutdown control end, and the second end of the second switch tube is connected to the first end of the thyristor, wherein the second switch tube is used to prevent voltage from being transmitted to the motor in the short circuit detection mode.

[0018] In an optional implementation, the short circuit detection module includes:

[0019] A first resistor, wherein a first end of the first resistor is connected to a first power supply end, and a second end of the first resistor is connected to a first end of the thyristor;

[0020] a second resistor, wherein a first end of the second resistor is connected to a first end of the thyristor, and a second end of the second resistor is connected to the control module;

[0021] A third resistor, a first end of the third resistor is connected to the second end of the second resistor, and a second end of the third resistor is grounded.

[0022] In an optional implementation manner, the short circuit detection module further includes:

[0023] a fourth resistor, wherein a first end of the fourth resistor is connected to a second end of the second resistor, and a second end of the fourth resistor is connected to the control module;

[0024] A clamping diode, wherein a first end of the clamping diode is connected to a preset reference voltage, a second end of the clamping diode is grounded, and a third end of the clamping diode is connected to the second end of the second resistor.

[0025] In an optional implementation, the circuit breaker detection module includes:

[0026] A driving unit, the driving unit is connected to the control module and the thyristor respectively, and the driving unit is used to receive the start signal and drive the thyristor;

[0027] A current detection unit is connected to the control module and the detection resistor respectively, and is used to collect the current of the detection resistor and transmit the detection current to the control module.

[0028] In an optional implementation, the driving unit includes:

[0029] A first triode, wherein a control end of the first triode is connected to the control module, and a first end of the first triode is grounded;

[0030] A second triode, wherein the control end of the second triode is connected to the second end of the first triode, the first end of the second triode is connected to a preset reference voltage, and the second end of the second triode is connected to the control end of the thyristor.

[0031] In an optional implementation, the driving unit includes:

[0032] a fifth resistor, wherein a first end of the fifth resistor is connected to the control end of the first transistor, and a second end of the fifth resistor is connected to the control module;

[0033] a sixth resistor, a first end of the sixth resistor being connected to the control end of the first transistor, and a second end of the sixth resistor being grounded;

[0034] a seventh resistor, wherein a first end of the seventh resistor is connected to the second end of the first transistor, and a second end of the seventh resistor is connected to the control end of the second transistor;

[0035] an eighth resistor, a first end of the eighth resistor being connected to the control end of the second transistor, and a second end of the eighth resistor being connected to a preset reference voltage;

[0036] a ninth resistor, wherein a first end of the ninth resistor is connected to the second end of the second triode, and a second end of the ninth resistor is connected to the control end of the thyristor;

[0037] A tenth resistor, wherein a first end of the tenth resistor is connected to the second end of the thyristor, and a second end of the tenth resistor is connected to the second end of the ninth resistor.

[0038] In an optional implementation, the current detection unit includes:

[0039] an eleventh resistor, a first end of the eleventh resistor being connected to the first end of the detection resistor;

[0040] a twelfth resistor, a first end of the twelfth resistor being connected to a second end of the detection resistor;

[0041] an operational amplifier, wherein a first end of the operational amplifier is connected to the second end of the eleventh resistor, a second end of the operational amplifier is connected to the second end of the twelfth resistor, a positive power supply terminal of the operational amplifier is connected to the preset reference voltage, and a negative power supply terminal of the operational amplifier is grounded;

[0042] a thirteenth resistor, a first end of the thirteenth resistor being connected to the first end of the operational amplifier, and a second end of the thirteenth resistor being connected to a preset reference voltage;

[0043] a fourteenth resistor, a first end of the fourteenth resistor being connected to the second end of the operational amplifier, and a second end of the fourteenth resistor being connected to the output end of the operational amplifier;

[0044] A fifteenth resistor, wherein a first end of the fifteenth resistor is connected to the output end of the operational amplifier, and a second end of the fifteenth resistor is connected to the control module.

[0045] In an optional implementation manner, the shutdown control circuit includes: a start relay and a fuse, and the switch module includes:

[0046] A third switch tube, wherein a first end of the third switch tube is connected to the start relay, a second end of the third switch tube is connected to the fuse, and a control end of the third switch tube is connected to the control module.

[0047] In an optional implementation, the shutdown detection circuit further includes:

[0048] a first varistor, wherein a first end of the first varistor is connected to a first end of the first diode, and a second end of the first varistor is connected to a first end of the thyristor;

[0049] A second varistor, wherein a first end of the second varistor is connected to a first end of the thyristor, and a second end of the second varistor is connected to a second end of the thyristor. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 is a structural diagram of a shutdown detection circuit according to an embodiment of the present invention;

[0052] Figure 2 is a schematic diagram of a three-phase motor application of a shutdown detection circuit according to an embodiment of the present invention;

[0053] Figure 3 is a schematic diagram of a single-phase motor application of another shutdown detection circuit according to an embodiment of the present invention;

[0054] Figure 4 is a detailed structural diagram of a shutdown detection circuit according to an embodiment of the present invention;

[0055] Figure 5 is a structural diagram of another shutdown detection circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0058] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0060] In this embodiment, a shutdown detection circuit is provided. Figure 1 As shown, the shutdown detection circuit is connected to the shutdown control circuit, the shutdown control circuit includes: a thyristor T1 and a motor control circuit B1, and the shutdown detection circuit includes:

[0061] A control module 20, the control module 20 is used to output a switching signal, the switching signal is used to switch between a short circuit detection mode and an open circuit detection mode;

[0062] Specifically, the shutdown detection circuit can be applied to three-phase motors as well as single-phase motors. The shutdown detection circuit detects the thyristor T1 before the whole machine is powered on and the motor is running. It can also detect the thyristor T1 when the shutdown circuit is started for motor shutdown control. The control module 20 can be a control chip. The short-circuit detection mode is used to detect whether the thyristor T1 is short-circuited, and the open-circuit detection mode is used to detect whether the thyristor T1 is open-circuited. Among them, the control module 20 is also used to enter the motor operation mode by outputting a switching signal when the detection of the thyristor T1 is completed.

[0063] Specifically, after the whole machine is powered on, the control module 20 performs a self-check process of the program code. The control module 20 reads and writes registers, operates the program pointer PC (Personal Computer), calibrates the clock, and performs CRC (Cyclic Redundancy Check) checks on RAM (Random Access Memory) and ROM (Read-Only Memory) to determine whether the controller is normal. When the control module 20 self-checks normally, a short circuit detection is performed.

[0064] A function switching module 10, the function switching module 10 is respectively connected to the first power supply end, the first end of the thyristor T1 and the control module 20, and is used to receive the switching signal and perform switching;

[0065] Specifically, the function switching module 10 is used to switch between the short circuit detection mode and the open circuit detection mode. Optionally, the function switching module 10 can be a switch device. The first power supply terminal can be any one of the three input power supplies in the three-phase motor, or any one of the input power supplies in the unidirectional motor.

[0066] A short-circuit detection module 30, the short-circuit detection module 30 is respectively connected to the first power supply terminal, the first end of the thyristor T1 and the control module 20, and the short-circuit detection module 30 is used for adjusting the input power supply voltage and outputting it;

[0067] The control module 20 is also used to receive the regulated input power supply voltage, and in the short-circuit detection mode, when it is detected that the regulated input power supply voltage is less than the first preset voltage value, confirm that the thyristor T1 is short-circuited;

[0068] Specifically, when the function switching module 10 is switched to the short circuit detection mode, the short circuit detection module 30 detects whether the thyristor T1 is broken down. Specifically, when the thyristor T1 is closed, the voltage at the first end of the thyristor T1 is detected. If the voltage is less than the first preset voltage value, it means that the thyristor T1 is broken down and turned on.

[0069] The control module 20 is also used to output a start signal;

[0070] A circuit breaking detection module 40, which is respectively connected to the control end of the thyristor T1, the detection resistor Rs1 and the control module 20, and is used to drive the thyristor T1 to turn on after receiving the start signal, and collect the detection current flowing through the detection resistor and then output it;

[0071] The control module 20 receives the detection current, and in the circuit breaking detection mode, when it is detected that the regulated input power supply voltage is greater than the second preset voltage value and the detection current is the preset current value, confirms that the thyristor T1 is circuit broken;

[0072] It should be noted that the open circuit detection is performed after the short circuit detection. After confirming that the thyristor T1 is not short-circuited, the open circuit detection of the thyristor T1 is performed.

[0073] Specifically, when the function switching module 10 is switched to the circuit breaking detection mode, the circuit breaking detection module 40 detects whether the thyristor T1 is open or damaged. Specifically, when the thyristor T1 is turned on, the voltage at the first end of the thyristor T1 is detected to be greater than the second preset voltage value, and when the current flowing through the detection resistor is detected to be 0, it indicates that the thyristor T1 is open or damaged, and the preset current value can be 0, that is, no current flows through the detection resistor. Optionally, the circuit breaking detection module 40 includes a circuit for driving the thyristor T1 and a circuit for detecting the current.

[0074] The control module 20 is also used to output a shutdown signal when it is detected that the thyristor T1 is short-circuited or open-circuited, so as to control the motor control circuit B1 to stop running;

[0075] The switch module 50 is connected to the control module 20 and the motor control circuit B1 respectively, and is used to be turned off after receiving the shutdown signal.

[0076] Specifically, when the control module 20 detects that the thyristor T1 is short-circuited or open-circuited, it outputs a shutdown signal to the switch module 50. At this time, the switch module 50 is turned off to disconnect the motor control circuit B1, thereby preventing the motor control circuit B1 from being turned on in a fault state.

[0077] The shutdown detection circuit provided by the present invention outputs a switching signal to the function switching module through the control module, so that when the function switching module is switched to the short-circuit detection mode, the input power supply voltage after voltage adjustment sent by the short-circuit detection module is received, and when it is detected that the input power supply voltage after voltage adjustment is less than the first preset voltage value, the thyristor is confirmed to be short-circuited, and the switching signal is output to the function switching module through the control module, so that when the function switching module is switched to the open circuit detection mode, the open circuit detection module is controlled to drive the thyristor to conduct, and at the same time, the detection current flowing on the detection current is collected, and the detection current is transmitted to the control module. When the control module detects that the regulated input power supply voltage is greater than the second preset voltage value and the detection current is the preset current value, the thyristor is confirmed to be open-circuited. When the control module detects that the thyristor is short-circuited or open-circuited, the control module controls the switch module to disconnect the motor control circuit to prevent the motor control circuit from being turned on in a fault state, that is, before the motor runs, whether the thyristor is damaged is detected, thereby greatly reducing safety hazards.

[0078] In some optional embodiments, Figure 2 and Figure 3 As shown, the function switching module includes:

[0079] A first switch tube K1, wherein a control end of the first switch tube K1 is connected to the control module 20, a first end of the first switch tube K1 is connected to the first power end, and a second end of the first switch tube K1 is connected to a first end of a first diode D1, wherein the first switch tube K1 is used to supply power to the short circuit detection module 30 in a short circuit detection mode;

[0080] A second switch tube K2, wherein a first end of the second switch tube K2 is connected to the shutdown control end, and a second end of the second switch tube K2 is connected to a first end of the thyristor T1, wherein the second switch tube K2 is used to prevent voltage from being transmitted to the motor in a short circuit detection mode.

[0081] refer to Figure 2 and Figure 3 RL1a, RL1b, and RL1c are the linkage switches of the start relay RL1, that is, when the start button SB1 is pressed, the start relay RL1 is electrically connected, and at this time RL1a, RL1b, and RL1c also act together, the normally open switch RL1a is closed, the normally closed switch RL1b is disconnected, and the normally open switch RL1c is closed. Among them, RL1c is the shutdown switch, that is, when the shutdown switch SB2 or SB3 is pressed, RL1 is disconnected, so that RL1c is restored to a closed state. At this time, the current flows through RL1c, the thyristor T1, and the detection resistor RS1 and then passes into the ground terminal, so that the motor stops running. The first end of the second switch tube K2 is connected to the shutdown switch RL1c, and the second end of the second switch tube K2 is connected to the first end of the thyristor T1. The first diode D1 is a freewheeling diode, that is, when the motor is controlled to stop running, the current can quickly flow into the ground terminal through the first diode D1.

[0082] In the short circuit detection mode, the first switch tube K1 and the second switch tube K2 are closed, and short circuit detection is performed by the short circuit detection module 30. In the open circuit detection mode, the first switch tube K1 and the second switch tube K2 are opened, and open circuit detection is performed by the open circuit detection module 40.

[0083] In some optional embodiments, Figure 2 , Figure 3 and Figure 4 As shown, the short circuit detection module 30 includes:

[0084] A first resistor R1, wherein a first end of the first resistor R1 is connected to a first power supply end, and a second end of the first resistor R1 is connected to a first end of the thyristor T1;

[0085] A second resistor R2, wherein a first end of the second resistor R2 is connected to a first end of the thyristor T1, and a second end of the second resistor R2 is connected to the control module 20;

[0086] A third resistor R3, a first end of the third resistor R3 is connected to the second end of the second resistor R2, and a second end of the third resistor R3 is grounded.

[0087] Specifically, the current at the first power supply end is transmitted to the first end of the thyristor T1 through the first resistor R1. At this time, if the thyristor T1 is short-circuited, the current passing through the first resistor R1 flows into the ground end through the thyristor T1 and the detection resistor RS1. If the thyristor T1 is short-circuited, the current is transmitted to the control module 20 after voltage division through the second resistor R2 and the third resistor R3. The voltage of the PWR CN2 signal can be detected by the control module 20. If the voltage of the PWR CN2 signal is detected to be less than the first preset voltage value, it is confirmed that the thyristor T1 is short-circuited.

[0088] Optionally, the control module 20 can detect the level signal of PWR CN2. If the PWR CN2 signal is a high level signal, it means that the PWR CN1 signal is also a high level signal, and it is confirmed that the thyristor T1 is not short-circuited. If the control module 20 detects that the PWRCN2 signal is a low level signal, it means that the PWR CN1 signal is also a low level signal, and it is confirmed that the thyristor T1 is short-circuited.

[0089] It should be noted that the first resistor R1 is a high-value resistor. A weak signal is provided through the first resistor R1. At this time, if the thyristor T1 is really short-circuited, the current is less than 1 mA, which will not cause the motor to run suddenly.

[0090] In some optional embodiments, Figure 4 As shown, the short circuit detection module 30 also includes:

[0091] a fourth resistor R4, wherein a first end of the fourth resistor R4 is connected to a second end of the second resistor R2, and a second end of the fourth resistor R4 is connected to the control module 20;

[0092] A clamping diode D2, wherein a first end of the clamping diode D2 is connected to a preset reference voltage VCC, a second end of the clamping diode D2 is grounded, and a third end of the clamping diode D2 is connected to the second end of the second resistor R2.

[0093] Specifically, the fourth resistor R4 is a coupling resistor used for matching the control module 20, and the clamping diode D2 is used for clamping the value of PWR CN2. It should be noted that the first capacitor C1 is a filter capacitor for the PWR CN2 signal.

[0094] In some optional embodiments, Figure 5 As shown, the circuit breaker detection module 40 includes:

[0095] A driving unit 41, wherein the driving unit 41 is connected to the control module 20 and the thyristor T1 respectively, and the driving unit 41 is used to receive the start signal and drive the thyristor T1;

[0096] Specifically, when performing the open circuit detection, the first switch tube K1 and the second switch tube K2 are closed, and the driving unit 41 is used to drive the thyristor T1 so that the thyristor T1 is turned on. After driving the thyristor T1, the open circuit detection is further performed.

[0097] The current detection unit 42 is connected to the control module 20 and the detection resistor RS1 respectively, and is used for collecting the current of the detection resistor RS1 and transmitting the detection current to the control module 20 .

[0098] Specifically, the control module 20 collects the current of the detection resistor RS1 after driving the thyristor T1. If the PWR CN1 signal is detected to be high through the PWR CN2 signal, it means that electricity is sent to the first end of the thyristor T1. At this time, if the current of the detection resistor RS1 is detected to be 0, it means that the thyristor T1 has a short circuit fault.

[0099] In some optional embodiments, Figure 4 As shown, the driving unit 41 includes:

[0100] A first transistor Q1, wherein a control end of the first transistor Q1 is connected to the control module 20, and a first end of the first transistor Q1 is grounded;

[0101] A second transistor Q2, wherein the control end of the second transistor Q2 is connected to the second end of the first transistor Q1, the first end of the second transistor Q2 is connected to a preset reference voltage VCC, and the second end of the second transistor Q2 is connected to the control end of the thyristor T1.

[0102] Specifically, the control module 20 outputs a BRK DRV signal to the first transistor Q1. If the BRK DRV signal is a high level signal, the first transistor Q1 is turned on and the voltage of the control terminal of the second transistor Q2 is pulled down, so that after the second transistor Q2 is turned on, the thyristor T1 is driven based on the preset reference voltage VCC.

[0103] In some optional embodiments, Figure 4 As shown, the driving unit 41 includes:

[0104] a fifth resistor R5, wherein a first end of the fifth resistor R5 is connected to the control end of the first transistor Q1, and a second end of the fifth resistor R5 is connected to the control module 20;

[0105] a sixth resistor R6, wherein a first end of the sixth resistor R6 is connected to the control end of the first transistor Q1, and a second end of the sixth resistor R6 is grounded;

[0106] a seventh resistor R7, wherein a first end of the seventh resistor R7 is connected to the second end of the first transistor Q1, and a second end of the seventh resistor R7 is connected to the control end of the second transistor Q2;

[0107] an eighth resistor R8, a first end of the eighth resistor R8 is connected to the control end of the second transistor Q2, and a second end of the eighth resistor R8 is connected to a preset reference voltage VCC;

[0108] a ninth resistor R9, wherein a first end of the ninth resistor R9 is connected to the second end of the second transistor Q2, and a second end of the ninth resistor R9 is connected to the control end of the thyristor T1;

[0109] A tenth resistor R10, wherein a first end of the tenth resistor R10 is connected to a second end of the thyristor T1, and a second end of the tenth resistor R10 is connected to a second end of the ninth resistor R9.

[0110] Specifically, the fifth resistor R5 and the sixth resistor R6 are driving resistors of the first transistor Q1, the seventh resistor R7 and the eighth resistor R8 are driving resistors of the second transistor Q2, and the ninth resistor R9 and the tenth resistor R10 are driving resistors of the thyristor T1. It should be noted that the second capacitor C2 is a filter capacitor for driving the thyristor T1 signal.

[0111] In some optional embodiments, Figure 4 As shown, the current detection unit 42 includes:

[0112] an eleventh resistor R11, a first end of the eleventh resistor R11 being connected to a first end of the detection resistor RS1;

[0113] A twelfth resistor R12, a first end of the twelfth resistor R12 is connected to the second end of the detection resistor RS1;

[0114] an operational amplifier A1, wherein a first end of the operational amplifier A1 is connected to a second end of the eleventh resistor R11, a second end of the operational amplifier A1 is connected to a second end of the twelfth resistor R12, a positive power supply end of the operational amplifier A1 is connected to the preset reference voltage VCC, and a negative power supply end of the operational amplifier A1 is grounded;

[0115] A thirteenth resistor R13, a first end of the thirteenth resistor R13 is connected to the first end of the operational amplifier A1, and a second end of the thirteenth resistor R13 is connected to a preset reference voltage VCC;

[0116] a fourteenth resistor R14, wherein a first end of the fourteenth resistor R14 is connected to the second end of the operational amplifier A1, and a second end of the fourteenth resistor R14 is connected to the output end of the operational amplifier A1;

[0117] A fifteenth resistor R15 , wherein a first end of the fifteenth resistor R15 is connected to the output end of the operational amplifier A1 , and a second end of the fifteenth resistor R15 is connected to the control module 20 .

[0118] Specifically, the eleventh resistor R11 , the twelfth resistor R12 , the thirteenth resistor R13 , the fourteenth resistor R14 , the fifteenth resistor R15 and the operational amplifier A1 collect the current of the detection resistor RS1 , amplify it and transmit it to the control module 20 , that is, transmit the BRK CUR signal to the control module 20 .

[0119] It should be noted that when the shutdown circuit is started, the control module 20 continuously collects the BRK CUR signal and determines the state of the thyristor T1 by detecting the magnitude of the BRK CUR signal.

[0120] In some optional embodiments, Figure 2 and Figure 3 As shown, the shutdown control circuit includes: a start relay RL1 and a fuse F1, and the switch module 50 includes:

[0121] A third switch tube K3 , wherein a first end of the third switch tube K3 is connected to the start relay RL1 , a second end of the third switch tube K3 is connected to the fuse F1 , and a control end of the third switch tube K3 is connected to the control module 20 .

[0122] Specifically, when the control module 20 detects that the thyristor T1 is short-circuited or open-circuited, it outputs a shutdown signal to the third switch tube K3. After receiving the shutdown signal, the third switch tube K3 is disconnected to prevent the start relay RL1 from closing, so as to prevent the motor from running in the event of a fault. In addition, the fuse F1 is used as a general protection device for the control and shutdown circuits. If it is opened when there is an overcurrent, any operation such as starting or stopping the motor cannot be performed.

[0123] In some optional implementations, the shutdown detection circuit further includes:

[0124] A first varistor VR1, wherein a first end of the first varistor VR1 is connected to a first end of the first diode D1, and a second end of the first varistor VR1 is connected to a first end of the thyristor T1;

[0125] A second varistor VR2 , wherein a first end of the second varistor VR2 is connected to a first end of the thyristor T1 , and a second end of the second varistor VR2 is connected to a second end of the thyristor T1 .

[0126] Specifically, the first varistor VR1 and the second varistor VR2 are used to limit the voltage of the thyristor T1 when it is working, so as to protect the thyristor T1.

[0127] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A shutdown detection circuit, characterized in that: The shutdown detection circuit is connected to the shutdown control circuit, the shutdown control circuit includes: a thyristor and a motor control circuit, and the shutdown detection circuit includes: A control module, the control module is used to output a switching signal, the switching signal is used to switch between a short circuit detection mode and an open circuit detection mode; A function switching module, the function switching module is respectively connected to the first power supply end, the first end of the thyristor and the control module, and is used to receive the switching signal and perform switching; A short-circuit detection module, the short-circuit detection module is respectively connected to the first power supply terminal, the first end of the thyristor and the control module, and the short-circuit detection module is used for adjusting the input power supply voltage and then outputting it; The control module is also used to receive the regulated input power supply voltage, and in the short-circuit detection mode, when it is detected that the regulated input power supply voltage is less than a first preset voltage value, confirm that the thyristor is short-circuited; The control module is also used to output a start signal; A circuit breaker detection module, which is connected to the control end of the thyristor, the detection resistor and the control module respectively, and is used to drive the thyristor to conduct after receiving the start signal, and collect the detection current flowing through the detection resistor and then output it; The control module receives the detection current, and in the circuit breaking detection mode, when it is detected that the regulated input power supply voltage is greater than a second preset voltage value and the detection current is a preset current value, confirms that the thyristor is circuit broken; The control module is also used to output a shutdown signal when a thyristor short circuit or open circuit is detected, so as to control the motor control circuit to stop running; A switch module is connected to the control module and the motor control circuit respectively, and is used to close after receiving the shutdown signal.

2. The shutdown detection circuit according to claim 1, characterized in that: The function switching module includes: A first switch tube, wherein a control end of the first switch tube is connected to the control module, a first end of the first switch tube is connected to the first power supply end, and a second end of the first switch tube is connected to the first end of the first diode, wherein the first switch tube is used to supply power to the short circuit detection module in a short circuit detection mode; A second switch tube, wherein the first end of the second switch tube is connected to the shutdown control end, and the second end of the second switch tube is connected to the first end of the thyristor, wherein the second switch tube is used to prevent voltage from being transmitted to the motor in the short circuit detection mode.

3. The shutdown detection circuit according to claim 2, characterized in that: The short circuit detection module comprises: A first resistor, wherein a first end of the first resistor is connected to a first power supply end, and a second end of the first resistor is connected to a first end of the thyristor; a second resistor, wherein a first end of the second resistor is connected to a first end of the thyristor, and a second end of the second resistor is connected to the control module; A third resistor, a first end of the third resistor is connected to the second end of the second resistor, and a second end of the third resistor is grounded.

4. The shutdown detection circuit according to claim 3, characterized in that: The short circuit detection module also includes: a fourth resistor, wherein a first end of the fourth resistor is connected to a second end of the second resistor, and a second end of the fourth resistor is connected to the control module; A clamping diode, wherein a first end of the clamping diode is connected to a preset reference voltage, a second end of the clamping diode is grounded, and a third end of the clamping diode is connected to the second end of the second resistor.

5. The shutdown detection circuit according to claim 1, characterized in that: The circuit breaker detection module comprises: A driving unit, the driving unit is connected to the control module and the thyristor respectively, and the driving unit is used to receive the start signal and drive the thyristor; A current detection unit is connected to the control module and the detection resistor respectively, and is used to collect the current of the detection resistor and transmit the detection current to the control module.

6. The shutdown detection circuit according to claim 5, characterized in that: The driving unit comprises: A first triode, wherein a control end of the first triode is connected to the control module, and a first end of the first triode is grounded; A second triode, wherein the control end of the second triode is connected to the second end of the first triode, the first end of the second triode is connected to a preset reference voltage, and the second end of the second triode is connected to the control end of the thyristor.

7. The shutdown detection circuit according to claim 6, characterized in that: The driving unit comprises: a fifth resistor, wherein a first end of the fifth resistor is connected to the control end of the first transistor, The second end of the fifth resistor is connected to the control module; a sixth resistor, a first end of the sixth resistor being connected to the control end of the first transistor, and a second end of the sixth resistor being grounded; a seventh resistor, wherein a first end of the seventh resistor is connected to the second end of the first transistor, and a second end of the seventh resistor is connected to the control end of the second transistor; an eighth resistor, a first end of the eighth resistor being connected to the control end of the second transistor, and a second end of the eighth resistor being connected to a preset reference voltage; a ninth resistor, wherein a first end of the ninth resistor is connected to the second end of the second triode, and a second end of the ninth resistor is connected to the control end of the thyristor; A tenth resistor, wherein a first end of the tenth resistor is connected to the second end of the thyristor, and a second end of the tenth resistor is connected to the second end of the ninth resistor.

8. The shutdown detection circuit according to claim 7, characterized in that: The current detection unit comprises: an eleventh resistor, a first end of the eleventh resistor being connected to the first end of the detection resistor; a twelfth resistor, a first end of the twelfth resistor being connected to a second end of the detection resistor; an operational amplifier, wherein a first end of the operational amplifier is connected to the second end of the eleventh resistor, a second end of the operational amplifier is connected to the second end of the twelfth resistor, a positive power supply terminal of the operational amplifier is connected to a preset reference voltage, and a negative power supply terminal of the operational amplifier is grounded; a thirteenth resistor, a first end of the thirteenth resistor being connected to the first end of the operational amplifier, and a second end of the thirteenth resistor being connected to a preset reference voltage; a fourteenth resistor, a first end of the fourteenth resistor being connected to the second end of the operational amplifier, and a second end of the fourteenth resistor being connected to the output end of the operational amplifier; A fifteenth resistor, wherein a first end of the fifteenth resistor is connected to the output end of the operational amplifier, and a second end of the fifteenth resistor is connected to the control module.

9. The shutdown detection circuit according to claim 1, characterized in that: The shutdown control circuit includes: a start relay and a fuse, and the switch module includes: A third switch tube, wherein a first end of the third switch tube is connected to the start relay, a second end of the third switch tube is connected to the fuse, and a control end of the third switch tube is connected to the control module.

10. The shutdown detection circuit according to claim 2, characterized in that: The shutdown detection circuit also includes: a first varistor, wherein a first end of the first varistor is connected to a first end of the first diode, and a second end of the first varistor is connected to a first end of the thyristor; A second varistor, wherein a first end of the second varistor is connected to a first end of the thyristor, and a second end of the second varistor is connected to a second end of the thyristor.

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