CN215452503U - Protection circuit of multi-output switching power supply - Google Patents
Protection circuit of multi-output switching power supply Download PDFInfo
- Publication number
- CN215452503U CN215452503U CN202120649500.3U CN202120649500U CN215452503U CN 215452503 U CN215452503 U CN 215452503U CN 202120649500 U CN202120649500 U CN 202120649500U CN 215452503 U CN215452503 U CN 215452503U
- Authority
- CN
- China
- Prior art keywords
- unit
- voltage
- circuit
- electrically connected
- 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 provides a protection circuit of a multi-output switching power supply, which comprises a rectifying unit, wherein the input end of the rectifying unit is electrically connected with a power supply circuit, and the output end of the rectifying unit is electrically connected with a filtering unit; the first end of the filtering unit is electrically connected with the rectifying unit, and the second end of the filtering unit is grounded; the first end of the voltage division unit is electrically connected with the first end of the filtering unit, the second end of the voltage division unit is electrically connected with the voltage stabilizing unit, and the third end of the voltage division unit is grounded; the first end of the voltage stabilizing unit is electrically connected with the second end of the voltage dividing unit, and the other end of the voltage stabilizing unit is electrically connected with the main control circuit; the switch power supply can realize effective protection under the conditions of any output short circuit and overlarge current by combining the current-limiting protection circuit, the short-circuit protection circuit and the master control circuit, and the magnitude of the current-limiting current can be realized by adjusting the voltage-dividing resistance value in the current-limiting circuit.
Description
Technical Field
The utility model relates to the field of protection circuits, in particular to a protection circuit of a multi-output switching power supply.
Background
The transducer product in the prior art has UL certification requirements: in the current limiting test, the current passing through any output path on the secondary side of the switching power supply must not exceed 8A (the test path is loaded, and the other paths are unloaded), and in order to achieve the purpose, the commonly adopted method is as follows: when a certain current is loaded to a certain value (less than 8A), the switching power supply enters a hiccup state to play a protection role.
At present, in the prior art, the circuit protection for the multiplexed output is generally adopted: the current-limiting protection is carried out in two ways of short-circuit protection and the protection function of the control chip, but the current passing through all output current-limiting tests cannot exceed 8A by adopting the protection schemes.
SUMMERY OF THE UTILITY MODEL
In order to overcome the defects of the prior art, the utility model aims to provide a protection circuit of a multi-output switching power supply, when the current of a main output circuit is increased (other output is in no-load), the voltage of other output circuits is driven to be increased, wherein the voltage of the current-limiting protection circuit is included, when the voltage of the current-limiting protection circuit is increased to a certain value, the current-limiting protection circuit transmits signals to a control chip of a main control circuit, so that the main control chip triggers a short-circuit protection circuit, the current of the output circuit is monitored, and the multi-output switching power supply is protected.
In order to achieve the purpose, the utility model adopts the following technical scheme:
the utility model provides a protection circuit of a multi-output switch power supply, which comprises
The input end of the rectifying unit is electrically connected with the power supply circuit, and the output end of the rectifying unit is electrically connected with the filtering unit;
the first end of the filtering unit is electrically connected with the rectifying unit, and the second end of the filtering unit is grounded;
the first end of the voltage division unit is electrically connected with the first end of the filtering unit, the second end of the voltage division unit is electrically connected with the voltage stabilizing unit, and the third end of the voltage division unit is grounded;
and the first end of the voltage stabilizing unit is electrically connected with the second end of the voltage dividing unit, and the other end of the voltage stabilizing unit is electrically connected with the main control circuit.
After the power supply of the power supply circuit is input, a voltage signal is output to the voltage division unit after rectification and filtering of the rectification unit and the filtering unit; when the voltage of the voltage division unit exceeds the rated voltage of the voltage stabilization unit, the voltage stabilization unit outputs an exceeding voltage signal to the main control circuit to trigger the protection logic.
Preferably, the device further comprises a load unit;
the load unit is connected between the filtering unit and the voltage dividing unit in parallel.
Preferably, the voltage dividing unit comprises a first voltage dividing module and a second voltage dividing module;
the first voltage division module is connected with the second voltage division module in series, the other end of the first voltage division module is electrically connected with the first end of the filtering unit, the voltage stabilizing unit is connected between the first voltage division module and the second voltage division module, and the other end of the second voltage division module is grounded.
Preferably, the first voltage division module is a resistor R2, and the second voltage division module is a resistor R3;
the resistor R2 is connected in series with the resistor R3, the other end of the resistor R2 is electrically connected with the first end of the filtering unit, the voltage stabilizing unit is connected between the resistor R2 and the resistor R3, and the other end of the resistor R3 is grounded.
Preferably, the rectifying unit is a diode D1;
the input end of the diode D1 is electrically connected with the power supply circuit, and the output end of the diode D1 is electrically connected with the filtering unit.
Preferably, the filtering unit is a capacitor C1;
a first end of the capacitor C1 is electrically connected with the rectifying unit, and a second end of the capacitor C1 is grounded.
Preferably, the voltage stabilizing unit is a voltage stabilizing diode Z1;
the first end of the voltage-stabilizing diode Z1 is electrically connected with the second end of the voltage-dividing unit, and the other end of the diode Z1 is electrically connected with the control chip of the main control circuit.
Preferably, the load unit is a resistor R1;
one end of the resistor R1 is connected to the connection position of the rectifying unit and the filtering unit, and the other end of the resistor R1 is grounded.
Preferably, the device also comprises a short-circuit protection circuit, wherein the short-circuit protection circuit is electrically connected with the main control circuit;
the short-circuit protection circuit comprises a resistor R16, a resistor R17, a resistor R18, a capacitor C11 and a comparator U3; the resistor R18 is connected with the master control circuit after being connected with the resistor R17 in series, the capacitor C11 is connected with the resistor R18 in parallel, the first end of the comparator U3 is connected with the resistor R16 in series and then is electrically connected with a power supply, the second end of the comparator U3 and the third end of the comparator U3 are connected with the two ends of the capacitor C11 in parallel, and the third end of the comparator U3 is grounded.
Preferably, the circuit further comprises a main feedback circuit, a switch unit and an output circuit;
the switch unit is electrically connected with the power supply circuit and the plurality of output circuits through the transformer, and the switch unit is electrically connected with the main control circuit.
The main feedback circuit comprises a photoelectric coupler; one end of the main feedback circuit is electrically connected with the output circuit, and the other end of the main feedback circuit is electrically connected with the main control circuit through a photoelectric coupler; the main feedback circuit feeds back the output state of the output circuit to the main control circuit through the photoelectric coupler.
The utility model has the beneficial effects that:
according to the protection circuit of the multi-output switching power supply, when the output is short-circuited, the voltage exceeding 6V is output to the short-circuit protection circuit through the pin 1 of the PWM control chip, and the short-circuit protection circuit can pull down the power supply voltage to be below 10V to close the drive to realize protection; in a current-limiting test, when the current in a main output circuit is gradually increased, the voltage VDD input to a current-limiting protection circuit by an input circuit is also gradually increased, the VDD is divided by R2 and R3 and then is added on a voltage-stabilizing tube Z1, when the rising voltage exceeds the voltage of the voltage-stabilizing tube Z1, the voltage-stabilizing tube is broken down, when the CS voltage of a pin 3 of a control chip U1 reaches 1V, the voltage of a pin 1 of a PWM control chip U1 exceeds 6V, the short-circuit protection circuit is triggered, the power supply voltage can be reduced to be below 10V through the short-circuit protection circuit, so that the driving output of the U1 is closed, the power supply stops working, and hiccups are repeatedly carried out to achieve a protection effect; the current limiting protection circuit has the effects of monitoring and protecting the current of the output circuit.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and 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, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of an overall circuit provided in an embodiment of the present invention;
fig. 2 is a first schematic circuit diagram of a current limiting protection circuit according to an embodiment of the present invention;
fig. 3 is a second schematic diagram of a current-limiting protection circuit according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a short-circuit protection circuit according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a power supply circuit provided in an embodiment of the present invention;
fig. 6 is a schematic diagram of a main feedback circuit according to an embodiment of the present invention.
The attached drawings are as follows: 1 a main control circuit; 2, a current limiting protection circuit; 21 a rectifying unit; 22 a filtering unit; 23 a voltage dividing unit; 231 a first voltage division module; 232 a second voltage division module; a 24 voltage stabilization unit; 25 a load cell; 3 short-circuit protection circuit; 4 a power supply circuit; 5 an output circuit; 51 a main output current; 6 main feedback circuit.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The technical scheme of the utility model is further explained by the specific implementation mode in combination with the attached drawings.
As shown in fig. 1 to 6, the protection circuit of the multiple output switching power supply provided in this embodiment includes a current limiting protection circuit 2, where the current limiting protection circuit 2 includes:
the input end of the rectifying unit 21 is electrically connected with the power supply circuit 4, and the output end of the rectifying unit 21 is electrically connected with the filtering unit 22;
a first end of the filtering unit 22 is electrically connected with the rectifying unit 21, and a second end of the filtering unit 22 is grounded;
a voltage dividing unit 23, a first end of the voltage dividing unit 23 is electrically connected with a first end of the filtering unit 22, a second end of the voltage dividing unit 23 is electrically connected with the voltage stabilizing unit 24, and a third end of the voltage dividing unit 23 is grounded;
and a voltage stabilizing unit 24, wherein a first end of the voltage stabilizing unit 24 is electrically connected with a second end of the voltage dividing unit 23, and the other end of the voltage stabilizing unit 24 is electrically connected with the main control circuit 1.
After the power supply of the power supply circuit 4 is input, the voltage signal is output to the voltage division unit 23 after being rectified and filtered by the rectification unit 21 and the filtering unit 22; when the voltage of the voltage dividing unit 23 exceeds the rated voltage of the voltage stabilizing unit 24, the voltage stabilizing unit 24 outputs the exceeded voltage signal to the main control circuit 1 to trigger the protection logic.
Preferably, a load unit 25; the load unit 25 is connected in parallel between the filter unit 22 and the voltage dividing unit 23.
Preferably, the voltage dividing unit 23 includes a first voltage dividing module 231 and a second voltage dividing module 232; the first voltage dividing module 231 is connected in series with the second voltage dividing module 232, the other end of the first voltage dividing module 231 is electrically connected with the first end of the filtering unit 22, the voltage stabilizing unit 24 is connected between the first voltage dividing module 231 and the second voltage dividing module 232, and the other end of the second voltage dividing module 232 is grounded.
Preferably, the first voltage divider block 231 is a resistor R2, and the second voltage divider block 232 is a resistor R3; the resistor R2 is connected in series with the resistor R3, the other end of the resistor R2 is electrically connected with the first end of the filtering unit 22, the voltage stabilizing unit 24 is connected between the resistor R2 and the resistor R3, and the other end of the resistor R3 is grounded.
Preferably, the rectifying unit 21 is a diode D1; the input terminal of the diode D1 is electrically connected to the power supply circuit 4, and the output terminal of the diode D1 is electrically connected to the filter unit 22.
Preferably, the filtering unit 22 is a capacitor C1; a first terminal of the capacitor C1 is electrically connected to the rectifying unit 21, and a second terminal of the capacitor C1 is grounded.
Preferably, the voltage regulation unit 24 is a voltage regulation diode Z1; a first end of the zener diode Z1 is electrically connected to the second end of the voltage dividing unit 23, and the other end of the diode Z1 is electrically connected to the control chip of the main control circuit 1.
Preferably, the load unit 25 is a resistor R1; one end of the resistor R1 is connected to the connection point of the rectifying unit 21 and the filtering unit 22, and the other end of the resistor R1 is grounded.
Specifically, the current-limiting protection circuit 2 in this embodiment specifically includes a voltage regulator tube Z1, a diode D1, a capacitor C1, a resistor R2, a resistor R3, and a resistor R1; a voltage regulator tube Z1, a resistor R2 and a diode D1 are sequentially connected in series, the resistor R3 is connected in parallel with the space between the voltage regulator tube Z1 and the resistor R2 and then grounded, one end of the resistor R1 connected in parallel with the resistor C1 is connected between the resistor R2 and the diode D1, and the other end of the resistor R1 is grounded; the other end of the voltage regulator tube Z1 is electrically connected with the input end of the main control circuit 1, and the other end of the diode D1 is electrically connected with the power supply circuit 4. Specifically, the rectifier diode D1, the filter capacitor C1, the voltage dividing resistors R2 and R3, and the load resistor R1; one end of a rectifier diode D1 is connected with the dotted end of the transformer auxiliary voltage winding, the other end is connected with dummy loads R1, R2 and C1, the other ends of R1 and C1 are connected with a bus ground, the other end of a resistor R2 is connected with the cathode of a voltage regulator tube Z1 and one end of R3, the anode of the voltage regulator tube Z1 is connected with a pin 3 of a current-type PWM control chip U1, and after rectification filtering and voltage division of voltage division resistors R2 and R3 are carried out through D1 and C1, a voltage signal is output, and the voltage is in direct proportion to the magnitude of the main output loading current; when the current of the main output circuit 51 is gradually increased, the voltage VDD rectified by D1 and filtered by C1 is also gradually increased, the VDD is divided by R2 and R3 and then is added on a voltage stabilizing tube Z1, when the rising voltage exceeds the voltage of the voltage stabilizing tube Z1, the voltage stabilizing tube is broken down to enable the voltage of a pin CS of a pin 3 of a control chip U1 to reach 1V, the voltage of a pin 1 of a current type PWM control chip U1 exceeds 6V, the short-circuit protection circuit 3 is triggered, and the power supply voltage can be reduced to be below 10V through the short-circuit protection circuit. The drive output of the U1 is turned off, the power supply stops working, and the voltage hiccups repeatedly in this way, so that the protection effect is achieved.
Further, the protection circuit of the multiple output switching power supply in this embodiment includes a power supply circuit 4, a switching unit, a plurality of output circuits 5, a short-circuit protection circuit 3, a current-limiting protection circuit 2, and a main control circuit 1; the power supply circuit 4 is electrically connected with the main control circuit 1, the power supply circuit 4 supplies power to the main control circuit 1, the input end of the current-limiting protection circuit 2 is connected with the input end of the power supply circuit 4 in parallel, the output end of the current-limiting protection circuit 2 is electrically connected with the main control circuit 1, the switch unit is electrically connected with the power supply circuit 4 and the plurality of output circuits 5 through a transformer, the switch unit is electrically connected with the main control circuit 1, and the short-circuit protection circuit 3 is electrically connected with the main control circuit 1; when any output circuit 5 is short-circuited or the current is too large, the main control circuit 1 and the short-circuit protection circuit 3 realize short-circuit protection, and the main control circuit 1 realizes the current limiting function through the current-limiting protection circuit 2 to control the current of the output circuit 5. Specifically, by combining the current-limiting protection circuit 2, the short-circuit protection circuit 3 and the main control circuit, the switching power supply can realize effective protection under the conditions of any output short circuit and overlarge current, and can realize the magnitude of the current-limiting current by adjusting the voltage-dividing resistance value in the current-limiting circuit.
Preferably, the main control circuit 1 includes a PWM control chip, a CS pin of the PWM control chip is electrically connected to the current-limiting protection circuit 2, the switch unit is electrically connected to OUT and CS pins of the PWM control chip, and the short-circuit protection circuit 3 is electrically connected to a COMP pin of the PWM control chip. Specifically, in this embodiment, the switch unit is an MOS transistor, the main control circuit 1 implements the voltage adjustment effect by controlling the conduction rate of the MOS transistor, the MOS transistor is an N-type MOS transistor, the gate of the N-type MOS transistor is electrically connected to the OUT pin of the PWM control chip, the source of the N-type MOS transistor is electrically connected to the CS pin of the PWM control chip and then grounded, the drain of the N-type MOS transistor is electrically connected to the bus, and the PWM control chip is a current-type PWM control chip UC 3844.
Specifically, the protection circuit for the multi-output switching power supply is characterized in that a power supply circuit 4, a switching unit and a plurality of output circuits 5 are connected through a transformer; the output end of the power supply circuit 4 outputs a VCC voltage, and the VCC output is used for providing a working voltage for the main control circuit 1.
The short-circuit protection circuit 3 is used for judging according to the signal of the main control circuit 1, when the COMP pin output of the main control circuit 1 exceeds 6V voltage, the short-circuit protection circuit 3 can pull down the power supply voltage to be below 10V to close the drive to realize the protection effect, in the current limiting test, after the output current of the output circuit 5 (except the main output circuit 51) is gradually increased, the power supply voltage of the power supply circuit 4 to the PWM control chip is gradually reduced, when the voltage is reduced to be below 10V, the switching power supply stops working, then the starting resistor of the power supply recharges the power supply voltage of the PWM control chip to 16V, the power supply can continue to work, if the current of the output circuit 5 is not reduced or disappears, the supply voltage is pulled below 10V, the power supply stops working, the voltage is hiccup repeatedly, the output current can be limited not to exceed a certain range, and the current-limiting protection effect is further realized;
however, when the main output 51 is tested, the short-circuit protection circuit 3 and the main control circuit 1 cannot make a protection response when the output current of the main output circuit 51 is increased to more than 8A, and the device is easily overheated and fails; at this time, the current-limiting protection circuit 2 is required to monitor and protect, when the current of the main output circuit 51 is increased, the main output voltage is reduced, the main feedback circuit 6 enables the main control circuit 1 to maintain the main output voltage value by increasing the conduction rate of the MOS tube of the input circuit, at this time, the voltage of the current-limiting protection circuit 2 is also increased, and when the voltage of the current-limiting protection circuit 2 exceeds the rated voltage of the voltage-stabilizing tube in the circuit by 1V, the main control circuit 1 triggers a short-circuit protection mechanism, namely triggers the protection process of the short-circuit protection circuit 3.
Preferably, the short-circuit protection circuit 3 includes a resistor R16, a resistor R17, a resistor R18, a capacitor C11, and a comparator U3; the resistor R18 is connected with the master control circuit 1 after being connected with the resistor R17 in series, the capacitor C11 is connected with the resistor R18 in parallel, the first end of the comparator U3 is connected with the resistor R16 in series and then is electrically connected with a power supply, the second end of the comparator U3 and the third end of the comparator U3 are connected with the two ends of the capacitor C11 in parallel, and the third end of the comparator U3 is grounded.
Preferably, the device further comprises a main feedback circuit 6, wherein the main feedback circuit 6 comprises a photocoupler; one end of the main feedback circuit 6 is electrically connected with the output circuit 5, and the other end of the main feedback is electrically connected with the main control circuit 1 through a photoelectric coupler; the main feedback circuit 6 feeds back the output state of the output circuit 5 to the main control circuit 1 through a photoelectric coupler. Specifically, the input circuit comprises an MOS tube, the MOS tube is used for switching, the G pole of the MOS tube is electrically connected with the OUT pin of the PWM control chip, the S pole of the MOS tube is electrically connected with the CS pin of the PWM control chip, and the PWM control chip realizes energy storage and transmission by controlling the MOS tube; preferably, the output circuit 5 includes a diode and a capacitor, the diode and the capacitor are connected in series and then connected in parallel to the transformer, the input end of the diode is connected to the transformer, the output end of the diode is electrically connected to the positive electrode of the capacitor, and the connection between the diode and the capacitor is the output end of the output circuit 5.
Preferably, the output circuit 5 includes a diode and a capacitor, the diode and the capacitor are connected in series and then connected in parallel to the transformer, the input end of the diode is connected to the transformer, the output end of the diode is electrically connected to the positive electrode of the capacitor, and the connection between the diode and the capacitor is the output end of the output circuit 5.
Preferably, the main feedback circuit 6 further includes a resistor R10, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a capacitor C6, and a comparator U2; the resistor R13 is connected in parallel with two ends of a light emitter of the photoelectric coupler, one end of the resistor R13 is connected in series with the resistor R10 and then connected to an output end, the other end of the resistor R13 is electrically connected with an output end of the comparator U2, the first end of the comparator is grounded, the resistor R14, the capacitor C6 and the resistor R12 are sequentially connected in series and then connected in parallel with two ends of the resistor R13 and the resistor R10, the resistor R12 is electrically connected with the output end, the resistor R14 is connected to a connection position of the resistor R13 and the comparator, one end of the resistor R15 is connected to a connection position of the capacitor C6 and the resistor R12, the other end of the resistor R15 is grounded, and the second end of the comparator is connected to a connection position of the resistor R12 and the resistor R15. Specifically, the present embodiment has a plurality of output circuits 5, and the main feedback circuit 6 is connected to any one of the output circuits 5 for feeding back the detection state to the main control circuit 1, so as to perform the above-mentioned output protection.
The utility model has the beneficial effects that:
according to the protection circuit of the multi-output switching power supply, when the output is short-circuited, the pin 1 of the PWM control chip outputs voltage exceeding 6V to the short-circuit protection circuit 3, and the short-circuit protection circuit 3 can pull down the power supply voltage to be below 10V to close the drive to realize protection; in a current-limiting test, when the current of the main output 51 is gradually increased, the voltage VDD of the current-limiting protection circuit 2 is also gradually increased, the VDD is divided by R2 and R3 and then is added on a voltage-stabilizing tube Z1, when the rising voltage exceeds the voltage of the voltage-stabilizing tube Z1, the voltage-stabilizing tube is broken down, when the CS voltage of a pin 3 of a control chip U1 reaches 1V, the voltage of a pin 1 of a PWM control chip U1 exceeds 6V, the short-circuit protection circuit 3 is triggered, the power supply voltage can be pulled down to be below 10V through the short-circuit protection circuit 3, so that the driving output of the U1 is closed, the power supply stops working, and the voltage is hiccup repeatedly so as to achieve a protection effect; finally, when the switching power supply of the embodiment tests main output current limiting, a voltage regulator tube is broken down by monitoring the voltage rise of VDD, when the voltage of a pin 3 of a current type PWM control chip U1 is larger than 1V, a short-circuit protection circuit 3 is triggered, and the power supply is turned off, so that the current limiting protection function is achieved.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (10)
1. A protection circuit of a multi-output switch power supply is characterized by comprising
The input end of the rectifying unit is electrically connected with the power supply circuit, and the output end of the rectifying unit is electrically connected with the filtering unit;
the first end of the filtering unit is electrically connected with the rectifying unit, and the second end of the filtering unit is grounded;
the first end of the voltage division unit is electrically connected with the first end of the filtering unit, the second end of the voltage division unit is electrically connected with the voltage stabilizing unit, and the third end of the voltage division unit is grounded;
the first end of the voltage stabilizing unit is electrically connected with the second end of the voltage dividing unit, and the other end of the voltage stabilizing unit is electrically connected with the main control circuit;
after the power supply of the power supply circuit is input, a voltage signal is output to the voltage division unit after rectification and filtering of the rectification unit and the filtering unit; when the voltage of the voltage division unit exceeds the rated voltage of the voltage stabilization unit, the voltage stabilization unit outputs an exceeding voltage signal to the main control circuit to trigger the protection logic.
2. The protection circuit of a multiple-output switching power supply according to claim 1, further comprising a load unit;
the load unit is connected between the filtering unit and the voltage dividing unit in parallel.
3. The protection circuit of a multiple-output switching power supply according to claim 1, wherein the voltage dividing unit comprises a first voltage dividing module and a second voltage dividing module;
the first voltage division module is connected with the second voltage division module in series, the other end of the first voltage division module is electrically connected with the first end of the filtering unit, the voltage stabilizing unit is connected between the first voltage division module and the second voltage division module, and the other end of the second voltage division module is grounded.
4. The protection circuit of claim 3, wherein the first voltage divider is a resistor R2, and the second voltage divider is a resistor R3;
the resistor R2 is connected in series with the resistor R3, the other end of the resistor R2 is electrically connected with the first end of the filtering unit, the voltage stabilizing unit is connected between the resistor R2 and the resistor R3, and the other end of the resistor R3 is grounded.
5. The protection circuit of a multiple-output switching power supply according to claim 1, wherein said rectifying unit is a diode D1;
the input end of the diode D1 is electrically connected with the power supply circuit, and the output end of the diode D1 is electrically connected with the filtering unit.
6. The protection circuit of claim 1, wherein the filtering unit is a capacitor C1;
the first end of the capacitor C1 is electrically connected with the rectifying unit, and the second end of the capacitor C1 is grounded.
7. The protection circuit of a multiple-output switching power supply according to claim 1, wherein the voltage-stabilizing unit is a voltage-stabilizing diode Z1;
the first end of the voltage-stabilizing diode Z1 is electrically connected with the second end of the voltage-dividing unit, and the other end of the diode Z1 is electrically connected with a control chip of the main control circuit.
8. The protection circuit of a multiple-output switching power supply according to claim 2, wherein the load unit is a resistor R1;
one end of the resistor R1 is connected to the connection position of the rectifying unit and the filtering unit, and the other end of the resistor R1 is grounded.
9. The protection circuit of a multiple-output switching power supply according to claim 1, further comprising a short-circuit protection circuit electrically connected to the main control circuit;
the short-circuit protection circuit comprises a resistor R16, a resistor R17, a resistor R18, a capacitor C11 and a comparator U3; the resistor R18 is connected with the master control circuit after being connected with the resistor R17 in series, the capacitor C11 is connected with the resistor R18 in parallel, the first end of the comparator U3 is connected with the resistor R16 in series and then is electrically connected with a power supply, the second end of the comparator U3 and the third end of the comparator U3 are connected with the two ends of the capacitor C11 in parallel, and the third end of the comparator U3 is grounded.
10. The protection circuit of a multiple-output switching power supply according to claim 1, wherein: the circuit also comprises a main feedback circuit, a switch unit and an output circuit;
the switch unit is electrically connected with the power supply circuit and the plurality of output circuits through a transformer, and the switch unit is electrically connected with the main control circuit;
the main feedback circuit comprises a photoelectric coupler; one end of the main feedback circuit is electrically connected with the output circuit, and the other end of the main feedback circuit is electrically connected with the main control circuit through the photoelectric coupler; and the main feedback circuit feeds back the output state of the output circuit to the main control circuit through the photoelectric coupler.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120649500.3U CN215452503U (en) | 2021-03-30 | 2021-03-30 | Protection circuit of multi-output switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120649500.3U CN215452503U (en) | 2021-03-30 | 2021-03-30 | Protection circuit of multi-output switching power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN215452503U true CN215452503U (en) | 2022-01-07 |
Family
ID=79703522
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120649500.3U Active CN215452503U (en) | 2021-03-30 | 2021-03-30 | Protection circuit of multi-output switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN215452503U (en) |
-
2021
- 2021-03-30 CN CN202120649500.3U patent/CN215452503U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10868466B2 (en) | Sense resistor fault detection | |
| US7215517B2 (en) | Constant-voltage switching power supply provided with overvoltage output protecting circuit, and electronic apparatus provided with overvoltage protecting circuit | |
| CN105450005B (en) | DC to DC converter | |
| US11955893B2 (en) | Switching power supply, power adapter and charger | |
| EP3817232B1 (en) | Nmos switch driving circuit and power supply device | |
| KR20160124700A (en) | Synchronous buck regulator with short circuit to voltage source protection | |
| US7719239B2 (en) | Fast field discharge for generator over-voltage control | |
| CN211859585U (en) | Overcurrent detection circuit and flyback switching power supply | |
| CN101958533B (en) | Current sensing resistor short circuit protection device and method for isolated power supply | |
| CN111668807B (en) | Overvoltage protection circuit for output port of battery test equipment | |
| CN215452503U (en) | Protection circuit of multi-output switching power supply | |
| CN117410937A (en) | High-power short-circuit protection and recovery system and working method thereof | |
| US10615681B2 (en) | Switching power supply circuit | |
| CN212231336U (en) | Switching power supply, power adapter and charger | |
| CN212210489U (en) | Novel peak voltage suppression circuit | |
| CN114336561A (en) | Direct current surge voltage suppression circuit | |
| CN113162009B (en) | Over-energy protection circuit, residual current device, electronic equipment and distribution box | |
| CN111478287A (en) | Charging pile switching power supply fault protection circuit and charging pile power supply | |
| CN213817222U (en) | Overvoltage protection circuit, switching power supply and electrical equipment | |
| CN108988297A (en) | Hiccup time control circuit and the Switching Power Supply comprising the circuit | |
| EP4300800A1 (en) | Switching power supply protection circuit and power supply system | |
| CN211209283U (en) | Protection circuit of switching power supply circuit, switching power supply circuit and frequency converter | |
| CN216981790U (en) | Switching power supply and resonant current detection circuit | |
| TWI808871B (en) | Trip circuit of circuit breaker using power converter and rechargeable battery | |
| CN212969049U (en) | Circuit protection device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |