CN218352168U - Short-circuit protection circuit for power supply - Google Patents
Short-circuit protection circuit for power supply Download PDFInfo
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- CN218352168U CN218352168U CN202222409328.1U CN202222409328U CN218352168U CN 218352168 U CN218352168 U CN 218352168U CN 202222409328 U CN202222409328 U CN 202222409328U CN 218352168 U CN218352168 U CN 218352168U
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Abstract
The utility model discloses a power short circuit protection circuit, which comprises a power supply circuit, a voltage comparison circuit, a switch circuit and a power utilization circuit, wherein the power supply circuit is connected with a power supply end; the voltage comparison circuit comprises a first comparator, the positive input end of the first comparator is connected with the output end of the power supply circuit, the negative input end of the first comparator is connected with the power supply end, and the output end of the first comparator is connected with the input end of the switching circuit; the switch circuit comprises a PMOS (P-channel metal oxide semiconductor) tube, the source electrode of the PMOS tube is connected with the output end of the power supply circuit, the grid electrode of the PMOS tube is connected with the output end of the first comparator, and the drain electrode of the PMOS tube is connected with the input end of the power utilization circuit; the switching circuit comprises a voltage stabilizing diode, the anode of the voltage stabilizing diode is connected with the grid electrode of the PMOS tube, and the cathode of the voltage stabilizing diode is connected with the output end of the power supply circuit. The utility model discloses can avoid the power short circuit to make the working circuit take place excessive pressure or under-voltage, the electronic board that leads to the working circuit damages, and the condition that can burn out the circuit when serious takes place.
Description
Technical Field
The utility model belongs to the technical field of the power short circuit protection, concretely relates to power short circuit protection circuit.
Background
In the current elevator control system, the power supply circuit is an important component of the hardware circuit of the elevator control system, and the hardware on the hardware circuit can normally operate only when the power supply circuit is normal. In order to protect the power supply circuit, various protection circuits, such as an overvoltage protection circuit, an overcurrent protection circuit, and an anti-reverse protection circuit, are used for the power supply circuit.
At present, in the existing overvoltage protection circuit, overcurrent protection circuit and reverse connection prevention protection circuit, circuit structures such as self-recovery diodes, fuses, voltage and current detection chips and self-locking are mostly adopted, but the circuit structures mostly protect between the input end and the output end of a power supply, and in a subsequent working circuit of the output end, a circuit for protecting the normal operation of the working circuit is lacked. When voltage conversion chip damages, the condition of short circuit can exist with output voltage in input voltage, protection circuit can be walked around to input voltage this moment, directly reach the output, can lead to subsequent working circuit to take place the condition of excessive pressure or under-voltage, and then lead to the fact certain damage to subsequent working circuit's electronic plate, can burn out the circuit when serious, if in elevator control system, can cause serious potential safety hazard, and when maintaining the electronic plate that damages, because welding or other operations, the condition of power supply end and output short circuit also probably can take place, can cause the secondary damage to the electronic plate.
Disclosure of Invention
An object of the utility model is to provide a power short circuit protection circuit, this power short circuit protection circuit can detect the comparison to power supply circuit's input and output, and when the voltage of output and input is unusual, in time cut off power supply circuit to follow-up working circuit's power supply, avoid the power short circuit to make working circuit take place excessive pressure or under-voltage, lead to working circuit's electron board to damage, can burn out the condition of circuit when serious and take place.
The technical scheme for achieving the purpose comprises the following steps.
The utility model provides a power short circuit protection circuit, which comprises a power supply circuit, a voltage comparison circuit, a switch circuit and a power utilization circuit, wherein the power supply circuit is connected with a power supply end;
the voltage comparison circuit comprises a first comparator, wherein the positive electrode input end of the first comparator is connected with the output end of the power supply circuit, the negative electrode input end of the first comparator is connected with the power supply end, and the output end of the first comparator is connected with the input end of the switching circuit;
the switch circuit comprises a PMOS (P-channel metal oxide semiconductor) tube, the source electrode of the PMOS tube is connected with the output end of the power supply circuit, the grid electrode of the PMOS tube is connected with the output end of the first comparator, and the drain electrode of the PMOS tube is connected with the input end of the power utilization circuit;
the switching circuit further comprises a voltage stabilizing diode, the anode of the voltage stabilizing diode is connected with the grid electrode of the PMOS tube, and the cathode of the voltage stabilizing diode is connected with the output end of the power supply circuit.
In some embodiments, the voltage comparison circuit further includes a first resistor and a second resistor, the first resistor has one end connected to the output terminal of the power supply circuit and the other end connected to the positive input terminal of the first comparator, and the second resistor has one end connected to the first resistor and the other end connected to the ground terminal of the power line.
In some embodiments, the voltage comparison circuit further includes a third resistor and a fourth resistor, one end of the third resistor is connected to the power supply terminal, the other end of the third resistor is connected to the negative input terminal of the first comparator, one end of the third resistor is connected to the fourth resistor, and the other end of the third resistor is connected to the wire ground terminal.
In some embodiments, the positive electrode of the first comparator is connected to the power supply terminal, the negative electrode of the first comparator is connected to a ground terminal of an electric wire, and the voltage comparison circuit further includes a first capacitor having one end connected to the positive electrode of the first comparator and the other end connected to the ground terminal of the electric wire.
In some embodiments, the switch circuit further includes a fifth resistor, where the fifth resistor is disposed between the first comparator and the zener diode, and one end of the fifth resistor is connected to the output end of the first comparator, and the other end of the fifth resistor is connected to the gate of the PMOS transistor.
In some embodiments, the switch circuit further includes a sixth resistor, the sixth resistor is disposed between the PMOS transistor and the zener diode, one end of the sixth resistor is connected to the fifth resistor, and the other end of the sixth resistor is connected to the output terminal of the power supply circuit.
In some embodiments, the switch circuit further includes a second capacitor, the second capacitor is disposed between the sixth resistor and the POMS, one end of the second capacitor is connected to the fifth resistor, and the other end of the second capacitor is connected to the output end of the power supply circuit.
In some embodiments, the power supply circuit includes a chip, an input of the chip is connected to the power supply terminal, an output of the chip is connected to a positive input terminal of the first comparator, the chip is provided with a second comparator, a negative input terminal of the second comparator is connected to a timing capacitor, and the other end of the timing capacitor is connected to a ground terminal of an electrical wire.
In some embodiments, the power supply circuit further includes a first step-down resistor, a second step-down resistor, an inductor, a light emitting diode, and a first diode, wherein a first triode is formed inside the chip, one end of the inductor is connected to an emitter of the first triode, the other end of the inductor is connected to an anode of the light emitting diode, a cathode of the light emitting diode is connected to a ground terminal of an electric wire, a cathode of the first diode is connected to one end of the inductor close to the chip, an anode of the first diode is connected to the ground terminal of the electric wire, one end of the first step-down resistor is connected to a negative input terminal of the second comparator, the other end of the first step-down resistor is connected to the ground terminal of the electric wire, one end of the second step-down resistor is connected to the negative input terminal of the second comparator, and the other end of the second step-down resistor is connected to the anode of the light emitting diode.
In some embodiments, a first filter circuit is disposed between the power input and the input of the chip, a second filter circuit is disposed between the output of the chip and the first comparator, the first filter circuit includes a plurality of first filter capacitors disposed in parallel, one end of each first filter capacitor is connected to the input of the chip, and the other end of each first filter capacitor is connected to the ground of the wire, the second filter circuit includes a plurality of second filter capacitors disposed in parallel, one end of each second filter capacitor is connected to the output of the chip, and the other end of each second filter capacitor is connected to the ground of the wire.
The utility model provides a power short circuit protection circuit sets up the PMOS pipe at switch circuit through setting up first comparator at voltage comparison circuit, the positive input end of first comparator with the output of power supply circuit is connected, the negative pole input end of first comparator with the power supply end is connected, the output of first comparator with the switch circuit the grid of PMOS pipe is connected, the source electrode of PMOS pipe with the output of power supply circuit is connected, the drain electrode of PMOS pipe with the input of power consumption circuit is connected;
presetting that the input voltage of a power supply end is greater than the output voltage of the output end of a power supply circuit, comparing the input voltage of the power supply end with the output voltage of the output end of the power supply circuit through a first comparator when the power supply circuit is used, judging that the voltage is normal when the input voltage of the power supply end is greater than the output voltage of the output end of the power supply circuit, outputting a low level through the first comparator, conducting a PMOS (P-channel metal oxide semiconductor) tube, and conducting the input end of an electricity utilization circuit through the PMOS tube by the output end of the power supply circuit to supply electricity for the electricity utilization circuit; when the input voltage of the power supply end is smaller than the output voltage of the output end of the power supply circuit, the voltage is judged to be abnormal, the first comparator outputs high level, the PMOS tube is cut off, the output end of the power supply circuit is disconnected with the input end of the power utilization circuit, and the power utilization circuit is protected from being damaged;
when the switching circuit and the voltage comparison circuit work abnormally and cannot protect the power utilization circuit, the voltage stabilizing diode plays a role in protecting the power utilization circuit and avoids the condition that the power utilization circuit is damaged or burnt;
this power short circuit protection circuit detects the comparison through input and the output to power supply circuit, and when the voltage of output and input was unusual, in time cut off power supply circuit and to follow-up work circuit's power supply, avoid the power short circuit to make work circuit take place excessive pressure or under-voltage, lead to work circuit's electronic plate to damage, can burn out the condition emergence of circuit when serious.
Drawings
Fig. 1 is a schematic circuit diagram of the present invention.
Description of reference numerals:
10. a power supply circuit; 20. a voltage comparison circuit; 30. a switching circuit; 40. an electricity utilization circuit; 41. a relay circuit; 42. an optocoupler circuit; 43. an MCU circuit; 50. a first filter circuit; 60. a second filter circuit; u1, a chip; u2, a first comparator; d1, a voltage stabilizing diode; d2, a light emitting diode;
d3, a first diode; r1, a first resistor; r2 and a second resistor; r3 and a third resistor; r4 and a fourth resistor; r5 and a fifth resistor; r6 and a sixth resistor; r7, a first step-down resistor; r8 and a second voltage reduction resistor; r9 and a seventh resistor; l1, an inductor; GND, wire ground; q1 and a PMOS tube; c1, a first filter capacitor; c2, a second filter capacitor; c3, a timing capacitor; c4, a first capacitor; c5, a second capacitor; vout, output voltage; v24, power supply end.
Detailed Description
To facilitate understanding of the present invention, specific embodiments thereof will be described in more detail below with reference to the accompanying drawings.
As used herein, unless otherwise specified or defined, "first, \ 8230," is used merely to distinguish between names, and does not denote a particular quantity or order.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items, unless specified or otherwise defined.
It should be noted that "fixed to" or "connected to" in this document may be directly fixed to or connected to one element or may be indirectly fixed to or connected to one element.
As shown in fig. 1, the power short-circuit protection circuit provided in this embodiment includes a power supply circuit 10, a voltage comparison circuit 20, a switch circuit 30, and a power utilization circuit 40, where the power supply circuit 10 is connected to a power supply terminal V24, an output terminal of the power supply circuit 10 is connected to an input terminal of the voltage comparison circuit 20 and an input terminal of the switch circuit 30, respectively, the input terminal of the voltage comparison circuit 20 is further connected to the power supply terminal V24, and is used to compare an input voltage of the power supply terminal V24 with an output voltage Vout of the power supply circuit 10, so as to control on and off of the switch circuit 30, and when the voltage comparison circuit controls the switch circuit 30 to be turned on, the output terminal of the power supply circuit 10 supplies power to the input terminal of the power utilization circuit 40 through the switch circuit 30.
The voltage comparison circuit 20 comprises a first comparator U2, a negative input end of the first comparator U2 is connected with a third resistor R3 and a fourth resistor R4, the other end of the third resistor R3 is connected with the power supply end V24, and the other end of the fourth resistor R4 is connected with a wire ground end GND, so that the input voltage of the power supply end V24 is subjected to voltage reduction processing by the third resistor R3 and the fourth resistor R4 and then is input to the negative input end of the first comparator U2; the positive input end of the first comparator U2 is connected with a first resistor R1 and a second resistor R2, the other end of the first resistor R1 is connected with the output end of the power supply circuit 10, and the other end of the second resistor R2 is connected with a wire ground GND, so that the output voltage Vout at the output end of the power supply circuit 10 is subjected to voltage reduction processing by the first resistor R1 and the second resistor R2 and then is input to the positive input end of the first comparator U2.
In the circuit design process, the resistance values of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are designed, so that the input voltage of the stepped-down power supply end V24 is greater than the output voltage Vout of the stepped-down power supply circuit 10; when the power supply circuit is used, the first comparator U2 compares the input voltage of the power supply end V24 with the output voltage Vout of the power supply circuit 10 after being stepped down, and when the stepped-down voltage of the input voltage of the power supply end V24 is greater than the stepped-down voltage of the output voltage Vout of the power supply circuit 10, the first comparator U2 outputs a low level to the switch circuit 30, the switch circuit 30 is turned on, and the power supply power supplies power to the power utilization circuit 40 through the switch circuit 30; when the input voltage of the power supply end V24 is lower than the output voltage Vout of the power supply circuit 10, it is determined that the power supply of the power supply circuit 10 is abnormal, the first comparator U2 outputs a high level to the switch circuit 30, and the switch circuit 30 is turned off, thereby preventing the electronic board of the power utilization circuit 40 from being damaged or even burning the circuit due to the power supply of the power supply circuit 10 to the power utilization circuit 40.
The positive pole of the first comparator U2 is connected to the power input end, the negative pole of the first comparator U2 is connected to the wire ground GND, the positive pole of the first comparator U2 is connected to the first capacitor C4, the other end of the first capacitor C4 is connected to the wire ground GND, and the first capacitor C4 is a filter capacitor for filtering an alternating current component of the voltage input to the first comparator U2 from the power supply end V24, so that the waveform of the voltage input to the first comparator U2 is smoother.
The switch circuit 30 includes a PMOS transistor Q1, a gate of the PMOS transistor Q1 is connected to a fifth resistor R5, and the other end of the fifth resistor R5 is connected to an output terminal of the first comparator U2. The fifth resistor R5 described in this embodiment is a current-limiting resistor, and is used to ensure that the output voltage Vout of the power supply circuit 10 is dropped by the fifth resistor and the sixth resistor and the first diode together play a role of protection when the circuit is abnormal in operation.
When the power supply circuit is used, when the first comparator U2 outputs a low level, the source electrode and the drain electrode of the PMOS tube Q1 are conducted, so that the output end of the power supply circuit is conducted with the input end of the power utilization circuit 40 to supply power to the power utilization circuit 40; when the first comparator U2 outputs a high level, the source and the drain of the PMOS transistor Q1 are disconnected, so that the output terminal of the power supply circuit and the input terminal of the power utilization circuit 40 are cut off, and the power utilization circuit 40 is protected from the occurrence of the situation that the electronic board is damaged or the circuit is burnt due to overvoltage or undervoltage of the power supply circuit 10.
The switching circuit 30 further includes a zener diode D1, an anode of the zener diode D1 is connected to the fifth resistor R5, and is connected to the output end of the first comparator U2 through the fifth resistor R5, and a cathode of the zener diode D1 is connected to the output end of the power supply circuit 10; when the voltage stabilizing diode is used, when the first comparator U2 detects that the voltages of the power supply end V24 and the output end of the power supply circuit 10 are abnormal, so that the voltages at the two ends of the voltage stabilizing diode D1 are greater than the voltage stabilizing value, the voltage stabilizing diode stabilizes the voltage within the voltage stabilizing value range, and the PMOS transistor Q1 and the power utilization circuit 40 are prevented from being damaged when the voltage of the output end of the power supply circuit is abnormally too high.
A sixth resistor R6 and a second capacitor C5 are arranged on the switch circuit 30, the sixth resistor R6 is arranged between the PMOS transistor Q1 and the zener diode D1, one end of the sixth resistor R6 is connected to the fifth resistor R5, and the other end is connected to the output end of the power supply circuit 10; the second capacitor C5 is arranged between the sixth resistor R6 and the POMS, one end of the second capacitor C5 is connected with the fifth resistor R5, and the other end is connected with the output end of the power supply circuit 10; the sixth resistor R6 and the second capacitor C5 described in this embodiment are used to perform a filtering function.
The power utilization circuit 40 described in this embodiment includes a relay circuit 41, an optical coupler circuit 42 and an MCU (micro control unit) circuit, one end of the relay circuit 41, the optical coupler circuit 42 and the MCU circuit 43 is connected to the drain of the PMOS transistor Q1, and the other end is connected to the ground GND of the electric wire.
The power supply circuit 10 comprises a chip U1, an input end of the chip U1 is connected to the power supply end V24, an output end of the chip U1 is respectively connected to an anode input end of the first comparator U2, a source electrode of the PMOS transistor Q1 and a cathode of the zener diode D1, and a ground end of the chip U1 is connected to a wire ground end GND; the power supply circuit 10 is provided with a first filter circuit 50, the first filter circuit 50 includes three first filter capacitors C1 connected in parallel, one end of the first filter capacitor C1 is connected to the power supply terminal V24, and the other end is connected to the wire ground terminal GND for filtering an ac component of the voltage input from the power supply terminal V24, so that the waveform of the voltage input to the chip U1 is smoother.
Of course, the first filter circuit 50 can also be used to filter the ac component of the input voltage of the power supply terminal V24, so that the waveform of the voltage input into the first comparator U2 is smoother.
A second comparator (not shown in the figure, the same applies below) is arranged on the chip U1, a cathode input end of the second comparator is a CI pin of the chip U1, the CI pin is connected with a first voltage-reducing resistor R7, the other end of the first voltage-reducing resistor R7 is connected with a seventh resistor R9, the other end of the seventh resistor R9 is connected with an anode of a light-emitting diode D2, and a cathode of the light-emitting diode D2 is connected with a ground terminal GND of an electric wire.
The led D2 described in this embodiment is used to indicate that there is a voltage output from the circuit.
And the CI pin is also connected with a second voltage reduction resistor R8, and the other end of the second voltage reduction resistor R8 is connected with a wire grounding end GND.
The TC pin of the chip U1 is connected with a timing capacitor C3, and the other end of the timing capacitor C3 is connected with a ground end GND of an electric wire.
A first triode (not shown, the same applies below) is arranged on the chip U1, an emitter of the first triode is an SE pin of the chip U1, an inductor L1 is connected to the SE pin of the chip U1, the other end of the inductor L1 is connected to an anode of the light emitting diode D2, a first diode D3 is further arranged on the power supply circuit 10, a cathode of the first diode D3 is connected to one end of the inductor L1 close to the chip U1, and an anode of the first diode D3 is connected to a ground end GND of an electric wire.
In this embodiment, the first voltage-reducing resistor R7, the second voltage-reducing resistor R8, the inductor L1, the light-emitting diode D2, and the first diode D3 are all connected to the output terminal of the power supply circuit 10.
A second filter circuit 60 is further arranged between the output end of the chip U1 and the first comparator U2, the second filter circuit 60 includes a plurality of second filter capacitors C2 arranged in parallel, one end of each second filter capacitor C2 is connected with the output end of the chip U1, the other end of each second filter capacitor C2 is connected with an electric wire grounding end GND, and the second filter capacitors C2 are used for passing through the output voltage Vout of the chip U1, so that the voltage waveform input to the first comparator U2 is smoother.
When the power supply circuit 10 provided in this embodiment is used, the purpose that the voltage input to the chip U1 at the power supply terminal V24 is subjected to voltage reduction processing by the first voltage reduction resistor R7 and the second voltage reduction resistor R8 and then different output voltages Vout are output through the output terminal of the power supply circuit 10 is achieved by changing the resistance values of the first voltage reduction resistor R7 and the second voltage reduction resistor R8;
when a second comparator in the chip U1 outputs a high level, the first triode is conducted, so that the chip U1 charges the timing capacitor C3 through the TC pin, the output voltage value is increased, and the purpose of stable voltage supply is achieved;
when the first triode is conducted, the chip U1 transmits voltage to the inductor L1 through the SE pin, the inductor L1 stores the voltage, when the second comparator in the chip U1 outputs a low level, the first triode is cut off, at the moment, the inductor L1 and the first diode D3 form a follow current loop due to the fact that the inductor L1 stores the voltage, and the follow current loop plays a role in stabilizing and providing a subsequent stable output voltage Vout.
In the power short-circuit protection circuit described in this embodiment, a first comparator U2 is disposed in a voltage comparison circuit 20, a PMOS transistor Q1 is disposed in a switch circuit 30, an anode input end of the first comparator U2 is connected to an output end of the power supply circuit 10, a cathode input end of the first comparator U2 is connected to the power supply end V24, an output end of the first comparator U2 is connected to a gate of the PMOS transistor Q1 of the switch circuit 30, a source of the PMOS transistor Q1 is connected to an output end of the power supply circuit 10, and a drain of the PMOS transistor Q1 is connected to an input end of the power utilization circuit 40;
presetting that the input voltage of a power supply end V24 is greater than the output voltage Vout of the output end of a power supply circuit 10, when the power supply circuit is used, comparing the voltage obtained by dividing the input voltage of the power supply end V24 by a third resistor R3 and a fourth resistor R4 with the voltage obtained by dividing the output voltage Vout of the output end of the power supply circuit 10 by a first resistor R1 and a second resistor R2 by a first comparator U2, when the voltage obtained by dividing the input voltage of the power supply end V24 by the third resistor R3 and the fourth resistor R4 is greater than the voltage obtained by dividing the output voltage Vout of the output end of the power supply circuit 10 by the first resistor R1 and the second resistor R2, judging that the voltage is normal, outputting a low level by the first comparator U2, conducting a PMOS tube Q1, conducting the output end of the power supply circuit 10 through the PMOS tube Q1 and conducting the input end of an electric circuit 40 to supply power for the electric circuit 40; when the voltage obtained by dividing the input voltage of the power supply end V24 by the third resistor R3 and the fourth resistor R4 is smaller than the voltage obtained by dividing the output voltage Vout of the output end of the power supply circuit 10 by the first resistor R1 and the second resistor R2, it is determined that the voltage is abnormal, the first comparator U2 outputs a high level, the PMOS transistor Q1 is turned off, the output end of the power supply circuit 10 is disconnected from the input end of the power utilization circuit 40, and the power utilization circuit 40 is protected from damaging the power utilization circuit 40;
by arranging the voltage stabilizing diode D1 in the switch circuit 30, the anode of the voltage stabilizing diode D1 is connected with the gate of the PMOS transistor Q1, and the cathode of the voltage stabilizing diode D1 is connected with the output end of the power supply circuit 10, the voltage stabilizing diode is in a cut-off state and does not work in normal use, and the voltage stabilizing diode can stabilize the voltage within a voltage stabilizing range thereof only when the voltage difference between two ends of the voltage stabilizing diode is greater than a voltage stabilizing value thereof under the abnormal condition of the circuit, so that the power utilization circuit 40 is protected, and the power utilization circuit 40 is prevented from being damaged or burnt;
this power short circuit protection circuit detects the comparison through the voltage that the input and the output to power supply circuit 10 gained behind the resistance partial pressure that corresponds, and when the voltage of output and input was unusual, in time cut off power supply circuit 10 and supply with to follow-up working circuit's power, avoid the power short circuit to make working circuit take place excessive pressure or under-voltage, lead to working circuit's electronic board to damage, can burn out the condition of circuit when serious and take place.
The above embodiments are not intended to be exhaustive list of the present invention, and there may be many other embodiments not listed. Any replacement and improvement made on the basis of not violating the conception of the utility model belong to the protection scope of the utility model.
Claims (10)
1. The power supply short circuit protection circuit is characterized by comprising a power supply circuit, a voltage comparison circuit, a switch circuit and a power utilization circuit, wherein the power supply circuit is connected with a power supply end;
the voltage comparison circuit comprises a first comparator, wherein the positive input end of the first comparator is connected with the output end of the power supply circuit, the negative input end of the first comparator is connected with the power supply end, and the output end of the first comparator is connected with the input end of the switch circuit;
the switch circuit comprises a PMOS (P-channel metal oxide semiconductor) tube, the source electrode of the PMOS tube is connected with the output end of the power supply circuit, the grid electrode of the PMOS tube is connected with the output end of the first comparator, and the drain electrode of the PMOS tube is connected with the input end of the power utilization circuit;
the switching circuit further comprises a voltage stabilizing diode, wherein the anode of the voltage stabilizing diode is connected with the grid electrode of the PMOS tube, and the cathode of the voltage stabilizing diode is connected with the output end of the power supply circuit.
2. The power supply short-circuit protection circuit according to claim 1, wherein the voltage comparison circuit further comprises a first resistor and a second resistor, one end of the first resistor is connected to the output terminal of the power supply circuit, the other end of the first resistor is connected to the positive input terminal of the first comparator, one end of the second resistor is connected to the first resistor, and the other end of the second resistor is connected to the ground terminal of the wire.
3. The power supply short-circuit protection circuit according to claim 1, wherein the voltage comparison circuit further comprises a third resistor and a fourth resistor, one end of the third resistor is connected to the power supply terminal, the other end of the third resistor is connected to the negative input terminal of the first comparator, one end of the third resistor is connected to the fourth resistor, and the other end of the third resistor is connected to a wire ground terminal.
4. The power supply short-circuit protection circuit according to claim 1, wherein a positive electrode of the first comparator is connected to the power supply terminal, a negative electrode of the first comparator is connected to a wire ground terminal, the voltage comparison circuit further comprises a first capacitor, one end of the first capacitor is connected to the positive electrode of the first comparator, and the other end of the first capacitor is connected to the wire ground terminal.
5. The short-circuit protection circuit of any one of claims 1 to 4, wherein the switch circuit further comprises a fifth resistor, the fifth resistor is disposed between the first comparator and the Zener diode, one end of the fifth resistor is connected to the output terminal of the first comparator, and the other end of the fifth resistor is connected to the gate of the PMOS transistor.
6. The short-circuit protection circuit of claim 5, wherein the switch circuit further comprises a sixth resistor, the sixth resistor is disposed between the PMOS transistor and the Zener diode, one end of the sixth resistor is connected to the fifth resistor, and the other end of the sixth resistor is connected to the output terminal of the power supply circuit.
7. The power supply short-circuit protection circuit as claimed in claim 6, wherein the switch circuit further comprises a second capacitor, the second capacitor is disposed between the sixth resistor and the POMS, one end of the second capacitor is connected to the fifth resistor, and the other end of the second capacitor is connected to the output terminal of the power supply circuit.
8. The power supply short circuit protection circuit according to any one of claims 1 to 4, wherein the power supply circuit comprises a chip, an input of the chip is connected with the power supply terminal, an output terminal of the chip is connected with a positive input terminal of the first comparator, a second comparator is arranged on the chip, a negative input terminal of the second comparator is connected with a timing capacitor, and the other end of the timing capacitor is connected with a wire grounding terminal.
9. The power supply short-circuit protection circuit according to claim 8, wherein the power supply circuit further includes a first step-down resistor, a second step-down resistor, an inductor, a light emitting diode, and a first diode, a first triode is formed inside the chip, one end of the inductor is connected to an emitter of the first triode, the other end of the inductor is connected to an anode of the light emitting diode, a cathode of the light emitting diode is connected to a wire ground terminal, a cathode of the first diode is connected to one end of the inductor close to the chip, an anode of the first diode is connected to the wire ground terminal, one end of the first step-down resistor is connected to a negative input terminal of the second comparator, the other end of the first step-down resistor is connected to the wire ground terminal, one end of the second step-down resistor is connected to a negative input terminal of the second comparator, and the other end of the second step-down resistor is connected to the anode of the light emitting diode.
10. The power short circuit protection circuit according to claim 8, wherein a first filter circuit is disposed between the power input terminal and the input terminal of the chip, a second filter circuit is disposed between the output terminal of the chip and the first comparator, the first filter circuit comprises a plurality of first filter capacitors connected in parallel, one end of each first filter capacitor is connected to the input terminal of the chip, and the other end of each first filter capacitor is connected to the ground terminal of the power line, the second filter circuit comprises a plurality of second filter capacitors connected in parallel, one end of each second filter capacitor is connected to the output terminal of the chip, and the other end of each second filter capacitor is connected to the ground terminal of the power line.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222409328.1U CN218352168U (en) | 2022-09-09 | 2022-09-09 | Short-circuit protection circuit for power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222409328.1U CN218352168U (en) | 2022-09-09 | 2022-09-09 | Short-circuit protection circuit for power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218352168U true CN218352168U (en) | 2023-01-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202222409328.1U Active CN218352168U (en) | 2022-09-09 | 2022-09-09 | Short-circuit protection circuit for power supply |
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| Country | Link |
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| CN (1) | CN218352168U (en) |
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2022
- 2022-09-09 CN CN202222409328.1U patent/CN218352168U/en active Active
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