CN210350768U - Protective circuit - Google Patents
Protective circuit Download PDFInfo
- Publication number
- CN210350768U CN210350768U CN201921006919.6U CN201921006919U CN210350768U CN 210350768 U CN210350768 U CN 210350768U CN 201921006919 U CN201921006919 U CN 201921006919U CN 210350768 U CN210350768 U CN 210350768U
- Authority
- CN
- China
- Prior art keywords
- capacitor
- voltage
- power supply
- driving module
- resistor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model relates to a protection circuit. The power supply circuit comprises a power supply input end, switching tubes Q1, Q2, Q3 and Q4, a driving module U1, a diode D1, biasing resistors R1, R2 and R5, voltage dividing resistors R3 and R4, a sampling resistor R6, a capacitor C1 and a starting module P1. When the client side is in overcurrent or short circuit, the ISENSE end of the U1 reaches a set voltage, the COMP output end outputs high level, the power supply input end stops supplying power to the power supply end VCC of the U1, and the OUT output control end of the U1 does not output PWM pulses. At this time, the start module charges the power supply terminal VCC of U1, and the machine is turned on. When the client side returns to normal, the OUT output control end of the U1 normally outputs PWM pulses, so that the problem that the switching power supply can recover output only when the switching power supply is required to reset input alternating current after the client side returns to normal due to the fact that a switching power supply is locked when the client side outputs overcurrent or short circuit in a traditional protection circuit is avoided.
Description
Technical Field
The utility model relates to a power electronic technology field especially relates to a protection circuit.
Background
With the rapid development of the switching power supply technology, the output isolation anti-reverse-filling circuit is mature, and the traditional isolation anti-reverse-filling circuit is generally realized by using MOS (metal oxide semiconductor) tubes or diodes.
However, such protection circuit is not suitable for the device whose actual load of the client is motor, motor or inductive, because the device of the client will reverse and generate energy, and the generated energy needs to be released by a loop, if the reverse-irrigation-preventing circuit is used, the client device will be easily burned out, because of the isolation, the energy cannot flow into the power supply, the energy can only be borne by the client device, and the client device cannot bear the high voltage, which causes damage. Therefore, if the load is an inductive device, the final energy is reversely charged into the power supply, but the electromagnetic induction generates electricity, so that the reversely charged voltage is higher than the output voltage of the power supply, and the reversely charged time of some devices is longer, so that the power supply is protected from overvoltage. To prevent overvoltage protection of the power supply, the capacity of the output electrolytic capacitor can only be increased, but this is difficult to achieve due to space problems. The traditional protection circuit supplies power through an auxiliary source, but the auxiliary source supplies power all the time, when the client outputs overcurrent or short circuit, the switching power supply can be locked, namely, the input alternating current needs to be closed, and the input alternating current is turned on again, so that the switching power supply can recover the output.
SUMMERY OF THE UTILITY MODEL
In view of the above, it is necessary to provide a protection circuit in order to solve the above problems.
A protection circuit comprises a power supply input end, a switch tube Q1, a switch tube Q2, a driving module U1, a switch tube Q3, a switch tube Q4, a diode D1, a bias resistor R1, a bias resistor R2, a voltage dividing resistor R3, a voltage dividing resistor R4, a bias resistor R5, a sampling resistor R6, a capacitor C1 and a starting module P1.
The input end of the switching tube Q1 is connected to the power input end and the connection end of one end of the bias resistor R1, the output end of the switching tube Q1 is connected to the anode of the diode D1 and is connected to the power supply end VCC of the driving module U1 through the diode D1; the control end of the switch tube Q1 is connected to the connection end of the other end of the bias resistor R1 and the input end of the switch tube Q2. The output terminal of the switching tube Q2 is grounded.
The COMP output end of the driving module U1 is connected to the control end of the switching tube Q3 through a voltage-dividing resistor R4 and a voltage-dividing resistor R3, and the COMP output end is grounded through a voltage-dividing resistor R4. The ISENSE terminal of the driving module U1 is connected with the client load through a sampling resistor R6 and is grounded through a capacitor C1. The OUT end of the driving module U1 is an output control end; a power supply terminal VCC of the driving module U1 is connected to the cathode of the diode D1, and a power supply terminal VCC of the driving module U1 is connected to one end of the starting module P1; the VREF terminal of the driving module U1 is connected to the connection terminal of the input terminal of the switching tube Q3 and the input terminal of the switching tube Q4.
The output end of the switching tube Q3 is connected to the control end of the switching tube Q4, the output end of the switching tube Q3 is grounded through a bias resistor R5, and the control end of the switching tube Q3 is grounded through a voltage dividing resistor R3; the output end of the switching tube Q4 is connected to the input end of the switching tube Q2 through a bias resistor R2; the starting module P1 is used for providing a starting current for the power supply terminal VCC of the driving module U1.
In one embodiment, the power input terminal of the protection circuit inputs a dc power voltage.
In one embodiment, the protection circuit further comprises a voltage regulator tube Z1, a capacitor C2, a capacitor C3 and a diode D2. The cathode of the voltage regulator tube Z1 is connected to the cathode of the diode D1, one end of the capacitor C3 and the connecting end of the power supply terminal VCC of the driving module U1, and the anode of the voltage regulator tube Z1 is grounded. One end of the capacitor C2 is connected to the connection end between the output end of the switching tube Q1 and the anode of the diode D1, and the other end of the capacitor C2 is grounded. One end of the capacitor C3 is connected to the connection end of the negative electrode of the diode D1, the negative electrode of the voltage regulator tube Z1 and the power supply terminal VCC of the driving module U1, and the other end of the capacitor C3 is grounded. The diode D2 is connected in parallel with the voltage-dividing resistor R4, the anode of the diode D2 is connected to the connection end of the voltage-dividing resistor R4 and the voltage-dividing resistor R3, and the cathode of the diode D2 is connected to the COMP end of the driving module U1.
In one embodiment, the protection circuit further comprises a capacitor C4, a capacitor C5, a capacitor C6 and a capacitor C7. One end of the capacitor C4 is connected to the power input terminal, and the other end of the capacitor C4 is grounded. One end of the capacitor C5 is connected to the output end of the switch tube Q4 and the connection end of the bias resistor R2, and the other end of the capacitor C5 is grounded. One end of the capacitor C6 is connected to the cathode of the diode D1, and the other end of the capacitor C6 is grounded. One end of the capacitor C7 is connected to the connection end of the voltage dividing resistor R4 and the voltage dividing resistor R3, and the other end of the capacitor C7 is grounded.
In one embodiment, the protection circuit further comprises a resistor R7, a capacitor C8 and a capacitor C9. One end of the resistor R7 is connected to the VREF end of the driving module U1, and the other end of the resistor R7 is connected to one end of the capacitor C8, one end of the capacitor C9 and the connecting end of the RT/CT end of the driving module U1; the other terminal of the capacitor C8 is connected to ground. The other end of the capacitor C9 is connected to the connection end of the ISENSE terminal of the drive module U1 and one end of the sampling resistor R6.
In one embodiment, the switching tube Q1, the switching tube Q2, the switching tube Q3 and the switching tube Q4 are transistors or MOS transistors.
In one embodiment, the switching transistor Q1 and the switching transistor Q2 are NPN transistors, and the switching transistor Q3 and the switching transistor Q4 are PNP transistors.
In one embodiment, the driving module includes a driving chip, and the model of the driving chip is UC28XX series or UC38XX series.
In one embodiment, the model of the driving chip is UC2844, and the resistance of the sampling resistor R6 is 510 ohms, 680 ohms, 820 ohms or 1000 ohms.
In one embodiment, the driving module U1 includes a comparator, which compares the sampling voltage of the sampling resistor R6 with the set voltage, and when the sampling voltage is equal to the set voltage, outputs a high level through the COMP output terminal of the driving module U1; when the sampling voltage is less than the set voltage, outputting a low level through a COMP output end of the driving module U1.
In one embodiment, the set voltage is 1 volt or 0.8 volt.
The conventional protection circuit supplies power to a power supply terminal VCC of a drive module U1 through an auxiliary source (namely, a voltage input by a power supply input terminal of the protection circuit), when an overcurrent or a short circuit occurs at a client terminal and an ISENSE terminal of the drive module U1 reaches a set voltage, a COMP output terminal of the drive module U1 outputs a high level, an OUT output control terminal of the drive module U1 does not output PWM pulses, the auxiliary source continuously supplies power to the power supply terminal VCC of the drive module U1, the COMP output terminal of the drive module U1 continuously outputs a high level, an OUT output control terminal of the drive module U1 continuously does not output PWM pulses, an output voltage of a switching power supply is continuously turned off, and the switching power supply is locked, that is, an input alternating current needs to be turned off, the input alternating current needs to be turned on again. When the client side has output reverse flow, the auxiliary source also continuously supplies power to the power supply end VCC of the drive module U1, the ISENSE end of the drive module U1 does not reach the set voltage, the COMP output end of the drive module U1 outputs low level, the OUT output control end of the drive module U1 continuously outputs PWM pulse signals, the output end of the switch power supply maintains the reverse flow voltage, and the switch power supply does not have overvoltage protection. The utility model provides a novel protection circuit, the ISENSE end of drive module U1 samples the customer end through sampling resistor R6, appear overflowing or the short circuit when the customer end, when the ISENSE end of drive module U1 reaches the settlement voltage, the COMP output high level of drive module U1, switch tube Q3 cuts off, Q4 switches on, export the high level to switch tube Q2's control end, Q2 switches on, the control end of Q1 that will be connected with Q2 input becomes the low level, Q1 cuts off, the power input end stops to supply power for the power end VCC of drive module U1, the OUT output control end of drive module U1 does not have the PWM pulse output, switching power supply's output voltage cuts off. At this time, the start module P1 charges the power supply terminal VCC of the driving module U1, and when the start threshold of the power supply terminal VCC is reached, the OUT output control terminal of the driving module U1 outputs the PWM pulse waveform, and the output voltage is established, but the current supplied to the power supply terminal VCC by the start module P1 is not enough to maintain the OUT output control terminal of the driving module U1 to continuously output the PWM pulse, so that the OUT output control terminal repeatedly generates pulse output and no pulse output, and the oscillation condition occurs. When the output load of the client side is recovered to be normal, the OUT output control end of the driving module U1 normally outputs PWM pulses, the COMP output end of the driving module U1 outputs low level, the switching tube Q3 is conducted, the Q4 is turned off, the low level is output to the control end of the Q2, the Q2 is turned off, the control end of the Q1 connected with the Q2 input end is changed into high level, the Q1 is conducted, the power supply input end supplies power to the driving module U1, the PWM pulse output of the OUT output control end of the driving module U1 is maintained, the problem that when the client side outputs overcurrent or short circuit, a switching power supply is locked, and when the client side outputs are recovered to be normal, input alternating current needs to be reset, and the switching power supply can recover the output is solved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, drawings of other embodiments can be obtained according to the drawings without creative efforts.
Fig. 1 is a circuit diagram of a protection circuit according to an embodiment of the present invention.
Detailed Description
In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein the term "and/or" includes any and all combinations of one or more of the associated listed items.
An embodiment of the utility model provides a protection circuit, including power input end VCC', switch tube Q1, switch tube Q2, drive module U1, switch tube Q3, switch tube Q4, diode D1, biasing resistance R1, biasing resistance R2, divider resistance R3, divider resistance R4, biasing resistance R5, sampling resistance R6, electric capacity C1, start-up module P1.
The input end of the switching tube Q1 is connected to the power supply input end VCC' and the connection end of one end of the bias resistor R1, the output end of the switching tube Q1 is connected to the anode of the diode D1, and is connected to the power supply end VCC of the driving module U1 through the diode D1; the control end of the switch tube Q1 is connected to the connection end of the other end of the bias resistor R1 and the input end of the switch tube Q2. The output terminal of the switching tube Q2 is grounded.
The COMP output end of the driving module U1 is connected to the control end of the switching tube Q3 through a voltage-dividing resistor R4 and a voltage-dividing resistor R3, and the COMP output end is grounded through a voltage-dividing resistor R4. The ISENSE terminal of the driving module U1 is connected with the client load through a sampling resistor R6 and is grounded through a capacitor C1. The OUT end of the driving module U1 is an output control end; a power supply terminal VCC of the driving module U1 is connected with the cathode of the diode D1, and a power supply terminal VCC of the driving module U1 is connected with one end of the starting module P1; the VREF terminal of the driving module U1 is connected to the connection terminal of the input terminal of the switching tube Q3 and the input terminal of the switching tube Q4.
The output end of the switching tube Q3 is connected to the control end of the switching tube Q4, the output end of the switching tube Q3 is grounded through a bias resistor R5, and the control end of the switching tube Q3 is grounded through a voltage dividing resistor R3; the output end of the switching tube Q4 is connected to the input end of the switching tube Q2 through a bias resistor R2; the starting module P1 is used for providing a starting current for the power supply terminal VCC of the driving module U1.
When the power input terminal VCC 'is turned on in the Q1, the power voltage input from the power input terminal VCC' supplies current to the power terminal VCC of the driving module U1 to maintain the output of the PWM pulse from the OUT terminal of the started driving module U1. Meanwhile, under the condition that the power supply voltage input by the power supply input end VCC supplies power to the power supply end VCC of the driving module U1, the circuit can supply voltage to the power supply output end without overvoltage protection under the condition that an external client side reversely fills for a long time.
In one embodiment, the power input of the protection circuit is fed with a dc supply voltage.
As shown in fig. 1, in one embodiment, the protection circuit further includes a voltage regulator tube Z1, a capacitor C2, a capacitor C3, and a diode D2. The cathode of the voltage regulator tube Z1 is connected to the cathode of the diode D1, one end of the capacitor C3 and the connecting end of the power supply terminal VCC of the driving module U1, and the anode of the voltage regulator tube Z1 is grounded. One end of the capacitor C2 is connected to the connection end between the output end of the switching tube Q1 and the anode of the diode D1, and the other end of the capacitor C2 is grounded. One end of the capacitor C3 is connected to the connection end of the negative electrode of the diode D1, the negative electrode of the voltage regulator tube Z1 and the power supply terminal VCC of the driving module U1, and the other end of the capacitor C3 is grounded. The diode D2 is connected in parallel with the voltage-dividing resistor R4, the anode of the diode D2 is connected to the connection end of the voltage-dividing resistor R4 and the voltage-dividing resistor R3, and the cathode of the diode D2 is connected to the COMP end of the driving module U1.
In the process that the power voltage input by the power input end VCC' supplies power to the driving module U1, the voltage regulator tube Z1 plays a role in power supply and voltage regulation.
As shown in fig. 1, in one embodiment, the protection circuit further includes a capacitor C4, a capacitor C5, a capacitor C6, and a capacitor C7. One end of the capacitor C4 is connected to the power input terminal, and the other end of the capacitor C4 is grounded. One end of the capacitor C5 is connected to the output end of the switch tube Q4 and the connection end of the bias resistor R2, and the other end of the capacitor C5 is grounded. One end of the capacitor C6 is connected to the cathode of the diode D1, and the other end of the capacitor C6 is grounded. One end of the capacitor C7 is connected to the connection end of the voltage dividing resistor R4 and the voltage dividing resistor R3, and the other end of the capacitor C7 is grounded.
In one embodiment, the protection circuit further comprises a resistor R7, a capacitor C8 and a capacitor C9. One end of the resistor R7 is connected to the VREF end of the driving module U1, and the other end of the resistor R7 is connected to one end of the capacitor C8, one end of the capacitor C9 and the connecting end of the RT/CT end of the driving module U1; the other terminal of the capacitor C8 is connected to ground. The other end of the capacitor C9 is connected to the connection end of the ISENSE terminal of the drive module U1 and one end of the sampling resistor R6.
The RT/CT terminal is an oscillation frequency pin of the driving module U1, and different working frequencies of the driving module can be set by selecting the resistor R7, the capacitor C8 and the capacitor C9 with different value combinations.
As shown in fig. 1, in an embodiment, the protection circuit further includes a feedback loop optocoupler P8-B, a resistor R8, and a capacitor C11, one end of the resistor R8 is connected to a VREF end of the driver module U1, the other end of the resistor R8 is connected to the input end of the feedback loop optocoupler P8-B and the connection end of one end of the capacitor C11, and the other end of the capacitor C11 is grounded.
The resistor R8 is used for compensating the working frequency of the driving module U1, and the capacitor C11 is a decoupling capacitor.
In one embodiment, the switching tube Q1, the switching tube Q2, the switching tube Q3 and the switching tube Q4 are transistors or MOS transistors. In one embodiment, the switch Q1 is an NPN transistor, the Q2 is an NPN transistor, the Q3 is a PNP transistor, and the Q4 is a PNP transistor.
In one embodiment, the driving module includes a driving chip, and the model of the driving chip is UC28XX series or UC38XX series.
In one embodiment, the model of the driver chip is UC2844, and the resistance of the sampling resistor R6 is 510 ohms, 680 ohms, 820 ohms, or 1000 ohms, and in other embodiments, the resistance of the sampling resistor R6 may be set according to actual needs.
In one embodiment, the driving module U1 includes a comparator, the comparator compares the sampling voltage of the sampling resistor R6 with the set voltage, when the sampling voltage is equal to the set voltage, the level of the COMP terminal is high through the internal logic of the driving module U1, and the COMP output terminal outputs high level; when the sampling voltage is less than the set voltage, the level of the COMP end is low through the internal logic of the driving module U1, and the COMP output end outputs a low level.
In one embodiment, the set voltage is 1 volt or 0.8 volt, and in other embodiments, the voltage value of the set voltage can be set according to actual needs.
The conventional protection circuit supplies power to a power supply terminal VCC of a drive module U1 through an auxiliary source (namely, a voltage input by a power supply input terminal of the protection circuit), when an overcurrent or a short circuit occurs at a client terminal and an ISENSE terminal of the drive module U1 reaches a set voltage, a COMP output terminal of the drive module U1 outputs a high level, an OUT output control terminal of the drive module U1 does not output PWM pulses, the auxiliary source continuously supplies power to the power supply terminal VCC of the drive module U1, the COMP output terminal of the drive module U1 continuously outputs a high level, an OUT output control terminal of the drive module U1 continuously does not output PWM pulses, an output voltage of a switching power supply is continuously turned off, and the switching power supply is locked, that is, an input alternating current needs to be turned off, the input alternating current needs to be turned on again. When the client side has output reverse flow, the auxiliary source also continuously supplies power to the power supply end VCC of the drive module U1, the ISENSE end of the drive module U1 does not reach the set voltage, the COMP output end of the drive module U1 outputs low level, the OUT output control end of the drive module U1 continuously outputs PWM pulse signals, the output end of the switch power supply maintains the reverse flow voltage, and the switch power supply does not have overvoltage protection. The utility model provides a novel protection circuit, the ISENSE end of drive module U1 samples the customer end through sampling resistor R6, appear overflowing or the short circuit when the customer end, when the ISENSE end of drive module U1 reaches the settlement voltage, the COMP output high level of drive module U1, switch tube Q3 cuts off, Q4 switches on, export the high level to switch tube Q2's control end, Q2 switches on, the control end of Q1 that will be connected with Q2 input becomes the low level, Q1 cuts off, the power input end stops to supply power for the power end VCC of drive module U1, the OUT output control end of drive module U1 does not have the PWM pulse output, switching power supply's output voltage cuts off. At this time, the start module P1 charges the power supply terminal VCC of the driving module U1, and when the start threshold of the power supply terminal VCC is reached, the OUT output control terminal of the driving module U1 outputs the PWM pulse waveform, and the output voltage is established, but the current supplied to the power supply terminal VCC by the start module P1 is not enough to maintain the OUT output control terminal of the driving module U1 to continuously output the PWM pulse, so that the OUT output control terminal repeatedly generates pulse output and no pulse output, and the oscillation condition occurs. When the output load of the client side is recovered to be normal, the OUT output control end of the driving module U1 normally outputs PWM pulses, the COMP output end of the driving module U1 outputs low level, the switching tube Q3 is conducted, the Q4 is turned off, the low level is output to the control end of the Q2, the Q2 is turned off, the control end of the Q1 connected with the Q2 input end is changed into high level, the Q1 is conducted, the power supply input end supplies power to the driving module U1, the PWM pulse output of the OUT output control end of the driving module U1 is maintained, the problem that when the client side outputs overcurrent or short circuit, a switching power supply is locked, and when the client side outputs are recovered to be normal, input alternating current needs to be reset, and the switching power supply can recover the output is solved.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.
Claims (10)
1. A protection circuit comprises a power input end and is characterized by further comprising a switch tube Q1, a switch tube Q2, a driving module U1, a switch tube Q3, a switch tube Q4, a diode D1, a bias resistor R1, a bias resistor R2, a voltage dividing resistor R3, a voltage dividing resistor R4, a bias resistor R5, a sampling resistor R6, a capacitor C1 and a starting module P1;
the input end of the switching tube Q1 is connected to the connection end of the power input end and one end of a bias resistor R1, the output end of the switching tube Q1 is connected to the anode of the diode D1, and is connected to the power supply end VCC of the driving module U1 through the diode D1, and the control end of the switching tube Q1 is connected to the connection end of the other end of the bias resistor R1 and the input end of the switching tube Q2;
the output end of the switching tube Q2 is grounded;
a COMP output end of the driving module U1 is connected to a control end of a switching tube Q3 through the voltage-dividing resistor R4 and the voltage-dividing resistor R3, and the COMP output end is grounded through the voltage-dividing resistor R4; the ISENSE end of the driving module U1 is connected with a client load through the sampling resistor R6, and is grounded through a capacitor C1; the OUT end of the driving module U1 is an output control end; the power supply terminal VCC of the driving module U1 is connected to the cathode of the diode D1, and the power supply terminal VCC of the driving module U1 is connected to one end of the starting module P1; the VREF end of the driving module U1 is connected to the connection end of the input end of the switch tube Q3 and the input end of the switch tube Q4;
the output end of the switching tube Q3 is connected to the control end of the switching tube Q4, the output end of the switching tube Q3 is grounded through the bias resistor R5, and the control end of the switching tube Q3 is grounded through the voltage-dividing resistor R3;
the output end of the switching tube Q4 is connected to the input end of the switching tube Q2 through a bias resistor R2;
the starting module P1 is used for providing a starting current for the power supply terminal VCC of the driving module U1.
2. The protection circuit according to claim 1, wherein the power supply input terminal inputs a direct-current power supply voltage.
3. The protection circuit according to claim 1, characterized in that the protection circuit further comprises a voltage regulator tube Z1, a capacitor C2, a capacitor C3 and a diode D2, wherein the cathode of the voltage regulator tube Z1 is connected to the cathode of the diode D1, one end of the capacitor C3 and the connection end of the power supply terminal VCC of the driving module U1, and the anode of the voltage regulator tube Z1 is grounded; one end of the capacitor C2 is connected to the connection end of the output end of the switch tube Q1 and the anode of the diode D1, and the other end of the capacitor C2 is grounded; one end of the capacitor C3 is connected to the connection end of the cathode of the diode D1, the cathode of the voltage regulator tube Z1 and the power supply terminal VCC of the driving module U1, and the other end of the capacitor C3 is grounded; the diode D2 is connected in parallel with the voltage-dividing resistor R4, the anode of the diode D2 is connected to the connection end of the voltage-dividing resistor R4 and the voltage-dividing resistor R3, and the cathode of the diode D2 is connected to the COMP end of the driving module U1.
4. The protection circuit of claim 1, further comprising a capacitor C4, a capacitor C5, a capacitor C6, and a capacitor C7, wherein one end of the capacitor C4 is connected to the power input terminal, and the other end of the capacitor C4 is grounded; one end of the capacitor C5 is connected to the output end of the switch tube Q4 and the connection end of the bias resistor R2, and the other end of the capacitor C5 is grounded; one end of the capacitor C6 is connected to the cathode of the diode D1, and the other end of the capacitor C6 is grounded; one end of the capacitor C7 is connected to the connection end of the voltage dividing resistor R4 and the voltage dividing resistor R3, and the other end of the capacitor C7 is grounded.
5. The protection circuit according to claim 1, further comprising a resistor R7, a capacitor C8, and a capacitor C9, wherein one end of the resistor R7 is connected to the VREF terminal of the driver module U1, and the other end of the resistor R7 is connected to the connection terminals of one end of the capacitor C8, one end of the capacitor C9, and the RT/CT terminal of the driver module U1; the other end of the capacitor C8 is grounded; the other end of the capacitor C9 is connected to the end of the driving module U1 connected to the ISENSE terminal and one end of the sampling resistor R6.
6. The protection circuit of claim 1, wherein the switch transistor Q1, the switch transistor Q2, the switch transistor Q3, and the switch transistor Q4 are transistors or MOS transistors.
7. The protection circuit of claim 1, wherein the driving module comprises a driver chip, and the model of the driver chip is UC28XX series or UC38XX series.
8. The protection circuit according to claim 7, wherein the model of the driving chip is UC2844, and the resistance of the sampling resistor R6 is 510 ohms, 680 ohms, 820 ohms or 1000 ohms.
9. The protection circuit of claim 1, wherein the driving module U1 comprises a comparator, the comparator compares a sampled voltage of the sampling resistor R6 with a set voltage, the sampled voltage outputs a high level through a COMP output terminal of the driving module U1 when the sampled voltage is equal to the set voltage, and the sampled voltage outputs a low level through a COMP output terminal of the driving module U1 when the sampled voltage is less than the set voltage.
10. The protection circuit of claim 9, wherein the set voltage is 1 volt or 0.8 volt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921006919.6U CN210350768U (en) | 2019-07-01 | 2019-07-01 | Protective circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921006919.6U CN210350768U (en) | 2019-07-01 | 2019-07-01 | Protective circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210350768U true CN210350768U (en) | 2020-04-17 |
Family
ID=70192311
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921006919.6U Active CN210350768U (en) | 2019-07-01 | 2019-07-01 | Protective circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210350768U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111541217A (en) * | 2020-04-24 | 2020-08-14 | 深圳市元征科技股份有限公司 | Short-circuit protection circuit, electrical equipment and electrical system |
| CN113867194A (en) * | 2021-09-11 | 2021-12-31 | 山东晨硕仪表有限公司 | NB-lot based Internet of things data integration terminal |
-
2019
- 2019-07-01 CN CN201921006919.6U patent/CN210350768U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111541217A (en) * | 2020-04-24 | 2020-08-14 | 深圳市元征科技股份有限公司 | Short-circuit protection circuit, electrical equipment and electrical system |
| CN113867194A (en) * | 2021-09-11 | 2021-12-31 | 山东晨硕仪表有限公司 | NB-lot based Internet of things data integration terminal |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101759808B1 (en) | Flyback converter for operation with very low input voltages | |
| EP2282398A1 (en) | Driving circuit for optocoupler | |
| CN210350768U (en) | Protective circuit | |
| CN101459331A (en) | Over voltage protection device, DC to DC voltage convertor and over voltage protection method | |
| CN102013802A (en) | BOOST circuit with short circuit protection function | |
| CN110855170A (en) | Photovoltaic inverter and capacitor discharge circuit | |
| CN108923631B (en) | A kind of switch power supply system and control circuit and device for switch power supply system | |
| CN213243514U (en) | Protection circuit and electronic equipment | |
| CN211508901U (en) | Power supply circuit and power supply device | |
| JP2013038941A (en) | Charge voltage control circuit and power supply circuit | |
| CN105991295B (en) | U interface remote supply feed circuit | |
| CN213990127U (en) | Switch protection circuit and switch power supply with same | |
| US20210226533A1 (en) | Converter, step-down method based on the converter and electronic device | |
| CN111883085B (en) | Device for improving stable work of liquid crystal equipment | |
| CN111725787B (en) | BOOST direct current short-circuit protection circuit that steps up | |
| CN210074760U (en) | Switching power supply output overvoltage protection circuit | |
| CN210380651U (en) | Power supply protection circuit and alternating current-direct current power supply conversion circuit | |
| CN113991611A (en) | Switching power supply and protection circuit thereof | |
| CN106533146B (en) | Soft start switch circuit and electronic device | |
| CN217824233U (en) | Voltage protection circuit and electric equipment | |
| CN216216605U (en) | Motor drive circuit and electrical equipment | |
| CN218006120U (en) | Spacecraft propulsion power supply conversion device | |
| CN219322275U (en) | Power supply circuit, auxiliary power supply and electronic equipment | |
| CN115360801B (en) | Charging control device and power supply apparatus | |
| CN213302883U (en) | Abnormal protection circuit for linear voltage stabilization reference and driving power supply |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |