Semiconductor control anti-backflow circuit
By introducing a semiconductor control mechanism into the anti-backflow circuit, detecting the current flow direction and controlling the switch, the problems of diode voltage drop and heating in the prior art are solved, and the stability of the circuit and the anti-backflow effect are improved.
Patent Information
- Application Number
- CN202421160116.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-24
- Publication Date
- 2025-02-28
- Estimated Expiration
- 2034-05-24
AI Technical Summary
In the existing anti-return circuit, the high voltage drop and heating problems of the diode lead to a reduced anti-return effect and insufficient stability.
A semiconductor control anti-return circuit is designed, and the current flow direction is identified through the detection device, the control device outputs a control signal, and the switching device controls the conduction state between the input and the output terminal according to the control signal to avoid the occurrence of the backflow phenomenon.
By detecting the current flow and controlling the switch, the backflow phenomenon is reduced, the circuit voltage drop is reduced, and the stability of the anti-backflow circuit is improved.
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of charging equipment, and in particular to a semiconductor control anti-backflow circuit. Background Art
[0002] The anti-backflow circuit refers to a circuit that disconnects the output and input when the charging device is not charging, thereby reducing the situation where the output voltage flows back to the input.
[0003] In the prior art, the anti-backflow circuit includes an input end and an output end. The input end is used to receive an input signal, and the output end is used to output a signal. Generally, a diode is connected in series between the input end and the output end. Through the excellent unidirectional conduction characteristics of the diode, the current in the circuit can only flow from the input end to the output end, thereby achieving the effect of anti-backflow.
[0004] When current flows between the two electrodes of a diode, a large voltage drop will be generated, causing the diode to heat up and thus reducing the circuit's backflow prevention effect. Utility Model Content
[0005] In order to improve the stability of the use of the anti-backflow circuit and reduce the voltage drop generated by the anti-backflow circuit, the utility model provides.
[0006] A semiconductor control anti-backflow circuit comprises an input end and an output end, and comprises a detection device, a control device and a switch device, wherein the detection device is used to identify the direction of an input signal of the input end and convert it into a direction signal, the control device is connected with the detection device and the input end to receive the direction signal and the input signal and output a control signal, and the switch device is connected with the control device to receive the control signal and respond to the control signal to control the conduction state between the input end and the output end;
[0007] When the current flows from the input end to the output end, the detection device outputs a high-level direction signal, the control device receives the high-level direction signal and the high-level input signal and outputs a high-level control signal, and the switch device receives the high-level control signal and controls the conduction between the input end and the output end; when the current flows from the output end to the input end, the detection device outputs a low-level direction signal, the control device receives the low-level direction signal and the high-level input signal and outputs a low-level control signal, and the switch device receives the low-level control signal and controls the disconnection between the input end and the output end.
[0008] By adopting the above technical solution, the detection device detects the direction of current flow in the circuit to determine whether backflow occurs. When backflow occurs, the control device controls the switch device to close the path between the input end and the output end to reduce the backflow phenomenon, thereby reducing the voltage drop generated by the circuit and improving the stability of the use of the anti-backflow circuit.
[0009] Preferably, a shunt device is further included, and the shunt device is used to adjust the size of the input signal flowing through the detection device.
[0010] By adopting the above technical solution, the magnitude of the input signal flowing through the detection device is limited by the shunt device, thereby ensuring the normal operation of the detection device and reducing the situation where the detection device is damaged due to excessive input signals.
[0011] Preferably, the detection device comprises a sampling module and a direction identification module, the sampling module is used to receive an input signal and convert it into a sampling signal, and the direction identification module is connected to the sampling module to receive the sampling signal and output a direction signal.
[0012] By adopting the above technical solution, the input signal is converted from current form to voltage form through the sampling module, and the direction identification module identifies the flow direction of the input signal by comparing the potentials at both ends of the sampling module.
[0013] Preferably, the detection device further comprises an isolation module, wherein the isolation module is connected to the sampling module to receive the sampling signal and output an isolation signal, and the direction identification module is connected to the isolation module to receive the isolation signal and output a direction signal.
[0014] By adopting the above technical solution, the sampling signal is transmitted from the sampling module to the direction identification module through the isolation device, thereby reducing the interference of the outside world on the sampling signal during transmission and improving the accuracy of the direction identification module in identifying the current flow direction.
[0015] Preferably, the control device comprises a reference module, a comparison module and a trigger module, wherein the reference module is used to provide a reference signal, the comparison module is connected with the reference module and the detection device to receive the reference signal and the direction signal and output a comparison signal, and the trigger module is connected with the comparison module to receive the comparison signal and output a control signal;
[0016] When the detection device outputs a high-level direction signal, the comparison module receives the high-level direction signal and the reference signal and outputs a high-level comparison signal, and the trigger module receives the high-level comparison signal and outputs a high-level control signal; when the detection device outputs a low-level direction signal, the comparison module receives the low-level direction signal and the reference signal and outputs a low-level comparison signal, and the trigger module receives the low-level comparison signal and outputs a low-level control signal.
[0017] By adopting the above technical solution, the trigger module is controlled according to the direction signal through the comparison module, so that when the current flows from the input end to the output end, the trigger module is controlled and then the switch device is controlled to open the path between the input end and the output end; when the current flows from the output end to the input end, the trigger module is controlled and then the switch device is controlled to close the path between the input end and the output end.
[0018] Preferably, the control device further comprises a logic module, the logic module is connected to the input terminal and the comparison module to receive the input signal and the comparison signal and output the logic signal, and the trigger module is connected to the logic module to receive the logic signal and output the control signal;
[0019] When the detection device outputs a high-level direction signal, the logic module receives the high-level comparison signal and the high-level input signal and outputs a high-level logic signal, and the trigger module receives the high-level logic signal and outputs a high-level control signal; when the detection device outputs a low-level direction signal, the logic module receives the low-level comparison signal and the high-level input signal and outputs a low-level logic signal, and the trigger module receives the low-level logic signal and outputs a low-level control signal.
[0020] By adopting the above technical solution, the input condition of the input end is detected by the logic module, so that when no signal is input to the input end, the trigger module is controlled and then the switch device is controlled to close the path between the input end and the output end.
[0021] Preferably, the reference module comprises a voltage stabilizing unit and a filtering unit, wherein the voltage stabilizing unit is connected to the input end to receive an input signal and output a reference signal, and the filtering unit is connected to the voltage stabilizing unit to filter out oscillations in the reference signal.
[0022] By adopting the above technical solution, a stable reference voltage signal is formed by the voltage stabilizing unit, and the oscillation in the reference signal is filtered out by the filtering unit, thereby improving the stability of the reference signal and reducing the situation where the circuit components are damaged due to the oscillation of the reference signal.
[0023] Preferably, a feedback device is further included, wherein the feedback device is connected to the switch device to receive an input signal and output a feedback signal to the detection device.
[0024] By adopting the above technical solution, feedback is formed in the circuit through the feedback device, so that the feedback signal output by the feedback device is more stable, and the situation where the damage of components caused by sudden changes in the feedback signal is reduced.
[0025] Preferably, the feedback device comprises a calibration module and a loop module, the calibration module is connected to the switch device to receive an input signal and output a feedback signal, and the loop module is connected to the calibration module to form a feedback loop.
[0026] By adopting the above technical solution, the signal output by the calibration module is input into the calibration module through the loop module, so that the signal output by the calibration module and the signal input into the calibration module are compared through the calibration module, thereby improving the feedback effect of the feedback device.
[0027] Preferably, the switching device includes an execution module and a protection module, the execution module is connected to the control device to receive a control signal and responds to the control signal to control the conduction state between the input end and the output end, and the protection module is connected to the execution module to reduce the situation where the execution module is broken down.
[0028] By adopting the above technical solution, the stability of the current passing through the execution module is improved through the protection module, thereby reducing the situation where the execution module is broken down and causing the switch device to fail, and improving the stability of the use of the switch device.
[0029] In summary, the present invention has at least one of the following beneficial technical effects:
[0030] 1. The detection device detects the direction of current flow in the circuit to determine whether backflow occurs. When backflow occurs, the control device controls the switch device to close the path between the input end and the output end to reduce the backflow phenomenon, thereby reducing the voltage drop generated by the circuit;
[0031] 2. The size of the input signal flowing through the detection device is limited by the shunt device, thereby ensuring the normal operation of the detection device and reducing the situation where the detection device is damaged due to excessive input signals;
[0032] 3. The input condition of the input terminal is detected by the logic module, so that when no signal is input to the input terminal, the trigger module is controlled and then the switch device is controlled to close the path between the input terminal and the output terminal. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 It is a circuit principle diagram of a semiconductor control anti-backflow circuit in this practical embodiment.
[0034] Figure 2 This is the circuit schematic of the reference module.
[0035] Explanation of the accompanying drawings: 1. Input end; 2. Output end; 3. Detection device; 31. Sampling module; 32. Direction identification module; 33. Isolation module; 4. Control device; 41. Reference module; 411. Voltage stabilization unit; 412. Filtering unit; 42. Comparison module; 43. Trigger module; 44. Logic module; 5. Switching device; 51. Execution module; 52. Protection module; 6. Shunt device; 7. Feedback device; 71. Calibration module; 72. Loop module. DETAILED DESCRIPTION
[0036] The following is combined with Figure 1-2 This utility is described in further detail.
[0037] Reference Figure 1The present practical embodiment discloses a semiconductor control anti-backflow circuit, including an input terminal 1, a detection device 3, a control device 4, a switch device 5 and an output terminal 2. The input terminal 1 is used to receive an input signal, the detection device 3 is used to detect the flow direction of the input signal in the circuit and convert it into a direction signal, the control device 4 is used to receive the direction signal and the input signal and output a control signal, and the switch device 5 is used to receive the control signal and control the opening and closing of the path between the input terminal 1 and the output terminal 2 according to the control signal.
[0038] The detection device 3 includes a sampling module 31, an isolation module 33 and a direction identification module 32. The sampling module 31 is used to convert the input signal into a sampling signal, the isolation module 33 is used to receive the sampling signal and output the isolation signal, and the direction identification module 32 is used to receive the isolation signal and output the direction signal.
[0039] The sampling module 31 includes a resistor R7 , and the sampling module 31 converts the input signal into the potentials of two points on the path from the input terminal 1 to the output terminal 2 .
[0040] The isolation module 33 includes an optical coupler U6, which is used to transmit the sampling signal to the direction identification module 32 and reduce interference in the transmission of the sampling signal.
[0041] The direction identification module 32 includes a chip U4 , which is an INA190-Q1 chip. The chip U4 is used to determine the direction of current flow according to the received signal.
[0042] One end of the resistor R7 is connected to an input terminal 1 of the optocoupler U6, the other end of the resistor R7 is connected to another input terminal 1 of the optocoupler U6 and then to the output terminal 2VOUT1, the positive output terminal 2 of the optocoupler U6 is connected to pin 4 of the chip U4, the negative output terminal 2 of the optocoupler U6 is connected to pin 5 of the chip U4, pin 3 of the chip U4 is connected to input terminal 1VIN1, and pin 2 of the chip U4 is connected to ground GND.
[0043] The control device 4 includes a reference module 41, a comparison module 42, a logic module 44 and a trigger module 43. The reference module 41 is used to provide a reference signal, the comparison module 42 is used to receive the direction signal and the reference signal and output a comparison signal, the logic signal is used to receive the comparison signal and the input signal and output a logic signal, and the trigger device is used to receive the logic signal and output a control signal.
[0044] The comparison module 42 includes a chip U3, a resistor R5 and a resistor R6. The chip U3 adopts a comparator chip of model TLV1701AIDCKR. The chip U3 is used to compare the reference signal and the direction signal. When the direction signal is greater than the reference signal, a high-level comparison signal is output. When the direction signal is less than the reference signal, a low-level comparison signal is output.
[0045] The logic module 44 includes a chip U2 and a resistor R2. The chip U2 is an integrated logic circuit chip of model TC7SET08FU. The chip U2 is used to control the output logic signal according to the size of the comparison signal and the input signal. The logic module 44 outputs a high-level logic signal when and only when the comparison signal and the input signal are both high-level.
[0046] The trigger module 43 includes a field effect transistor Q2, a diode D2 and a resistor R3. The field effect transistor Q2 is an N-channel field effect transistor of model 2N7002LT1.
[0047] The output terminal 2 of the reference module 41 is connected to one end of the resistor R6 and then to pin 1 of the chip U4, the other end of the resistor R6 is connected to pin 3 of the chip U3 and then to one end of the resistor R5, the other end of the resistor R5 is connected to the ground GND, the 6th pin of the chip U4 is connected to the 1st pin of the chip U3, the 2nd pin of the chip U3 is connected to the ground GND, the 5th pin of the chip U3 is connected to the input terminal 1VIN1, the 4th pin of the chip U3 is connected to the 2nd pin of the chip U2, the 3rd pin of the chip U2 is connected to the ground GND, the 5th pin of the chip U2 is connected to the input terminal 1VIN1, the 1st pin of the chip U2 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the input terminal 1VIN1, the 4th pin of the chip U2 is connected to one end of the resistor R3 and then to the gate of the field effect transistor Q2, the other end of the resistor R3 is connected to the input terminal 1VIN1, the drain of the field effect transistor Q2 is connected to the ground GND and then to the positive electrode of the diode D2.
[0048] The switch device 5 comprises an execution module 51 and a protection module 52 . The execution module 51 is used to control the conduction state of the path between the input terminal 1 and the output terminal 2 , and the protection module 52 is used to reduce the situation where the execution module 51 is broken down.
[0049] The execution module 51 includes a field effect transistor Q1 and a resistor R4. The field effect transistor Q1 is a P-channel field effect transistor. The protection module 52 includes a diode D1. The field effect transistor Q1 and the diode D1 are integrated into a chip for easy installation. In this embodiment, a chip U1 with a model number of CSD25402Q3A is used.
[0050] The cathode of the diode D2 is connected to the source of the field effect transistor Q2, and then to the 4th pin of the chip U1, and then to one end of the resistor R4. The other end of the resistor R4 is connected to the 5th, 6th, 7th and 8th pins of the chip U1, and then to the input terminal 1VIN1.
[0051] It also includes a shunt device 6 and a feedback device 7 . The shunt device 6 is used to adjust the current flowing through the detection device 3 , and the feedback device 7 is used to receive an input signal and output a feedback signal to the detection device 3 .
[0052] The shunt device 6 includes a resistor R1, a calibration module 71 and a loop module 72, the calibration module 71 is connected to the switch device 5 to receive an input signal, the loop module 72 is used to form a feedback loop, the calibration module 71 includes a comparator N1, and the loop module 72 includes a resistor R8 and a resistor R9.
[0053] One end of the resistor R1 is connected to the input terminal 1VIN1, the other end of the resistor R1 is connected to the ground GND, pins 1, 2 and 3 of the chip U1 are connected to the positive input terminal 1 of the comparator N1, the negative input terminal 1 of the comparator N1 is connected to one end of the resistor R8 and then to one end of the resistor R9, the other end of the resistor R9 is connected to the ground GND, the output terminal 2 of the comparator N1 is connected to the other end of the resistor R8 and then to the other end of the resistor R7 and then to the positive input terminal 1 of the optocoupler U6.
[0054] Reference Figure 1 and Figure 2 The reference module 41 includes a voltage stabilizing unit 411 and a filtering unit 412. The voltage stabilizing unit 411 is used to output a stable reference signal, and the filtering unit 412 is used to filter out the oscillation in the reference signal. The voltage stabilizing unit 411 includes a resistor R10 and a chip U5. The chip U5 uses a voltage stabilizing chip model ZXRE125. The filtering unit 412 includes a capacitor C1.
[0055] One end of the resistor R10 is connected to the input terminal 1VIN1, the other end of the resistor R10 is connected to the 3rd pin of the chip U5, and then to one end of the capacitor C1, and then to one end of the resistor R6, the 2nd pin of the chip U5 is connected to the ground GND, and the other end of the capacitor C1 is connected to the ground GND.
[0056] Working principle:
[0057] When the current flows from the input terminal 1 to the output terminal 2, the detection device 3 outputs a high-level direction signal, the control device 4 receives the high-level direction signal and the high-level input signal and outputs a high-level control signal, and the switch device 5 receives the high-level control signal and controls the conduction between the input terminal 1 and the output terminal 2;
[0058] When the current flows from the output terminal 2 to the input terminal 1, the detection device 3 outputs a low-level direction signal, the control device 4 receives the low-level direction signal and the high-level input signal and outputs a low-level control signal, and the switching device 5 receives the low-level control signal and controls the disconnection between the input terminal 1 and the output terminal 2.
[0059] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A semiconductor control anti-backflow circuit, comprising an input terminal (1) and an output terminal (2), characterized in that: The invention comprises a detection device (3), a control device (4) and a switch device (5), wherein the detection device (3) is used to identify the direction of an input signal of an input end (1) and convert it into a direction signal, the control device (4) is connected to the detection device (3) and the input end (1) to receive the direction signal and the input signal and output a control signal, and the switch device (5) is connected to the control device (4) to receive the control signal and respond to the control signal to control the conduction state between the input end (1) and the output end (2); When current flows from the input end (1) to the output end (2), the detection device (3) outputs a high-level direction signal, the control device (4) receives the high-level direction signal and the high-level input signal and outputs a high-level control signal, and the switch device (5) receives the high-level control signal and controls the input end (1) and the output end (2) to be connected; when current flows from the output end (2) to the input end (1), the detection device (3) outputs a low-level direction signal, the control device (4) receives the low-level direction signal and the high-level input signal and outputs a low-level control signal, and the switch device (5) receives the low-level control signal and controls the input end (1) and the output end (2) to be disconnected.
2. A semiconductor control anti-backflow circuit according to claim 1, characterized in that: It also comprises a shunt device (6), wherein the shunt device (6) is used to adjust the magnitude of the input signal flowing through the detection device (3).
3. The semiconductor control anti-backflow circuit according to claim 1, characterized in that: The detection device (3) comprises a sampling module (31) and a direction identification module (32), wherein the sampling module (31) is used to receive an input signal and convert it into a sampling signal, and the direction identification module (32) is connected to the sampling module (31) to receive the sampling signal and output a direction signal.
4. A semiconductor control anti-backflow circuit according to claim 3, characterized in that: The detection device (3) further comprises an isolation module (33), wherein the isolation module (33) is connected to the sampling module (31) to receive a sampling signal and output an isolation signal, and the direction identification module (32) is connected to the isolation module (33) to receive an isolation signal and output a direction signal.
5. The semiconductor control anti-backflow circuit according to claim 1, characterized in that: The control device (4) comprises a reference module (41), a comparison module (42) and a trigger module (43), wherein the reference module (41) is used to provide a reference signal, the comparison module (42) is connected to the reference module (41) and the detection device (3) to receive the reference signal and the direction signal and output a comparison signal, and the trigger module (43) is connected to the comparison module (42) to receive the comparison signal and output a control signal; When the detection device (3) outputs a high-level direction signal, the comparison module (42) receives the high-level direction signal and the reference signal and outputs a high-level comparison signal, and the trigger module (43) receives the high-level comparison signal and outputs a high-level control signal; when the detection device (3) outputs a low-level direction signal, the comparison module (42) receives the low-level direction signal and the reference signal and outputs a low-level comparison signal, and the trigger module (43) receives the low-level comparison signal and outputs a low-level control signal.
6. A semiconductor control anti-backflow circuit according to claim 5, characterized in that: The control device (4) further comprises a logic module (44), wherein the logic module (44) is connected to the input terminal (1) and the comparison module (42) to receive an input signal and a comparison signal and output a logic signal, and the trigger module (43) is connected to the logic module (44) to receive a logic signal and output a control signal; When the detection device (3) outputs a high-level direction signal, the logic module (44) receives the high-level comparison signal and the high-level input signal and outputs a high-level logic signal, and the trigger module (43) receives the high-level logic signal and outputs a high-level control signal; when the detection device (3) outputs a low-level direction signal, the logic module (44) receives the low-level comparison signal and the high-level input signal and outputs a low-level logic signal, and the trigger module (43) receives the low-level logic signal and outputs a low-level control signal.
7. The semiconductor control anti-backflow circuit according to claim 5, characterized in that: The reference module (41) comprises a voltage stabilizing unit (411) and a filtering unit (412); the voltage stabilizing unit (411) is connected to the input end (1) to receive an input signal and output a reference signal; and the filtering unit (412) is connected to the voltage stabilizing unit (411) to filter out oscillations in the reference signal.
8. The semiconductor control anti-backflow circuit according to claim 1, characterized in that: It also comprises a feedback device (7), wherein the feedback device (7) is connected to the switch device (5) to receive an input signal and output a feedback signal to the detection device (3).
9. The semiconductor control anti-backflow circuit according to claim 8, characterized in that: The feedback device (7) comprises a calibration module (71) and a loop module (72); the calibration module (71) is connected to the switch device (5) to receive an input signal and output a feedback signal; the loop module (72) is connected to the calibration module (71) to form a feedback loop.
10. The semiconductor control anti-backflow circuit according to claim 1, characterized in that: The switch device (5) comprises an execution module (51) and a protection module (52); the execution module (51) is connected to the control device (4) to receive a control signal and respond to the control signal to control the conduction state between the input terminal (1) and the output terminal (2); and the protection module (52) is connected to the execution module (51) to reduce the situation where the execution module (51) is broken down.