CN219351270U - Output overvoltage control circuit of switching power supply - Google Patents

Output overvoltage control circuit of switching power supply Download PDF

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Publication number
CN219351270U
CN219351270U CN202320327956.7U CN202320327956U CN219351270U CN 219351270 U CN219351270 U CN 219351270U CN 202320327956 U CN202320327956 U CN 202320327956U CN 219351270 U CN219351270 U CN 219351270U
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resistor
electrically connected
power supply
switching power
voltage source
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万锋
王余溪
黄洪力
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Xiamen Nengruikang Electronics Co ltd
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Xiamen Nengruikang Electronics Co ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

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Abstract

The utility model relates to the technical field of output overvoltage control, in particular to an output overvoltage control circuit of a switching power supply, which comprises a field effect transistor Q1, a capacitor C1, a triode Q2, a phototriode U1B, a light emitting diode U1A and a reference voltage source chip U2, wherein the grid electrode of the field effect transistor Q1 is respectively and electrically connected with the emitting electrode of the triode Q2 and one end of the phototriode U1B, the voltage reference end of the reference voltage source chip U2 is electrically connected with the anode of the light emitting diode U1A, the cathode of the light emitting diode U1A is electrically connected with the cathode end of the reference voltage source chip U2, accurate monitoring of output voltage is realized through the reference voltage source chip U2, when the output abnormality is that the phototriode U1B and the light emitting diode U1A conduct signals to a primary turn-off the field effect transistor Q1, the protection effect of the switching power supply is started, when the abnormality is relieved, no signal is fed back to the primary, the field effect transistor Q1 is normally conducted, and the switching power supply normally works.

Description

Output overvoltage control circuit of switching power supply
Technical Field
The utility model relates to the technical field of output overvoltage control, in particular to an output overvoltage control circuit of a switching power supply.
Background
In most electronic products, the power supply part is important, and good power supply protection is more indispensable, so that the follow-up important circuits and components can be protected from being damaged due to external overvoltage; along with the development of the times, the control of the output overvoltage protection in the switching power supply is also accurate and intelligent, and the accurate range can be reached to the design control of the product. The traditional scheme is that the overvoltage circuit is controlled through the main power chip, only the output of the product is turned off, the main power chip cannot be disconnected with the main loop, so that the main power chip is repeatedly started, the damage risk exists, and the output overvoltage protection value cannot be accurately designed.
Disclosure of Invention
In order to overcome the defects in the prior art, the technical problems to be solved by the utility model are as follows: the output overvoltage control circuit of the switching power supply can monitor output voltage in real time, and can directly disconnect a main loop when output overvoltage occurs, so that a main power chip is disconnected from the main loop, the protection of a product is achieved, and the product works normally when abnormal release occurs.
In order to solve the technical problems, the utility model adopts the following technical scheme:
the utility model provides an output overvoltage control circuit of switching power supply, includes field effect transistor Q1, electric capacity C1, triode Q2, phototriode U1B, emitting diode U1A and reference voltage source chip U2, the grid of field effect transistor Q1 is connected with triode Q2's projecting pole, electric capacity C1's one end, phototriode U1B's one end electricity respectively, triode Q2's collecting electrode is connected with electric capacity C1's the other end, phototriode U1B's projecting pole and the ground terminal of the main power chip of the switching power supply of peripheral hardware respectively, reference voltage source chip U2's voltage reference end is connected with emitting diode U1A's positive pole electricity, emitting diode U1A's negative pole is connected with reference voltage source chip U2's negative pole end electricity, reference voltage source chip U2's positive pole end is connected with the power supply end of the main power chip of the switching power supply of peripheral hardware.
Further, the device further comprises a resistor R1 and a resistor R2, wherein one end of the resistor R1 is electrically connected with the drain electrode of the field effect transistor Q1, the other end of the resistor R1 is electrically connected with one end of the resistor R2, and the other end of the resistor R2 is electrically connected with one end of the capacitor C1.
Further, the LED lamp further comprises a resistor R5, a resistor R6 and a resistor R7, wherein one end of the resistor R5 is electrically connected with one end of the resistor R6, one end of the resistor R7 and a voltage reference end of the reference voltage source chip U2 respectively, the other end of the resistor R6 is electrically connected with the other end of the resistor R7, an anode end of the reference voltage source chip U2 and a power supply end of a main power chip of a peripheral switching power supply respectively, and the other end of the resistor R5 is electrically connected with an anode of the LED U1A.
Further, the LED lamp further comprises a resistor R3 and a resistor R4, wherein one end of the resistor R3 is electrically connected with the anode of the LED U1A and one end of the resistor R4 respectively, and the other end of the resistor R4 is electrically connected with the cathode of the LED U1A and the cathode end of the reference voltage source chip U2 respectively.
Further, the transistor further comprises a resistor R11, one end of the resistor R11 is electrically connected with the source electrode of the field effect transistor Q1, and the other end of the resistor R11 is electrically connected with one end of the capacitor C1, the emitter electrode of the triode Q2 and the collector electrode of the phototriode U1B respectively.
Further, the three-phase current collector further comprises a resistor R8, a resistor R9 and a resistor R10, wherein one end of the resistor R8 is electrically connected with the emitter of the triode Q2, the other end of the resistor R8 is electrically connected with one end of the capacitor C1, one end of the resistor R10 and the grid electrode of the field effect transistor Q1 respectively, the other end of the resistor R10 is electrically connected with one end of the resistor R9 and the collector electrode of the phototriode U1B respectively, and the other end of the resistor R9 is electrically connected with the base electrode of the triode Q2.
Further, the LED lamp further comprises a voltage stabilizing tube ZD1, wherein the cathode of the voltage stabilizing tube ZD1 is electrically connected with one end of a capacitor C1, and the other end of the voltage stabilizing tube ZD1 is electrically connected with the other end of the capacitor C1, the collector of a triode Q2, the emitter of a phototriode U1B and the ground end of a main power chip of a peripheral switching power supply respectively.
The utility model has the beneficial effects that:
through setting up field effect transistor Q1, electric capacity C1, triode Q2, phototriode U1B, emitting diode U1A and reference voltage source chip U2, realize the accurate control to output voltage through reference voltage source chip U2, when the output is unusual, it is to elementary turn-off field effect transistor Q1 to pass through phototriode U1B and emitting diode U1A conduction signal, start the guard action to switching power supply, when the unusual dismantlement, no signal feedback is to elementary, field effect transistor Q1 normally switches on, switching power supply normally works, thereby realize output overvoltage protection.
Drawings
Fig. 1 is a schematic circuit diagram of an output overvoltage control circuit of a switching power supply according to the present utility model.
Detailed Description
In order to describe the technical contents, the achieved objects and effects of the present utility model in detail, the following description will be made with reference to the embodiments in conjunction with the accompanying drawings.
Referring to fig. 1, the present utility model provides the following technical solutions:
the utility model provides an output overvoltage control circuit of switching power supply, includes field effect transistor Q1, electric capacity C1, triode Q2, phototriode U1B, emitting diode U1A and reference voltage source chip U2, the grid of field effect transistor Q1 is connected with triode Q2's projecting pole, electric capacity C1's one end, phototriode U1B's one end electricity respectively, triode Q2's collecting electrode is connected with electric capacity C1's the other end, phototriode U1B's projecting pole and the ground terminal of the main power chip of the switching power supply of peripheral hardware respectively, reference voltage source chip U2's voltage reference end is connected with emitting diode U1A's positive pole electricity, emitting diode U1A's negative pole is connected with reference voltage source chip U2's negative pole end electricity, reference voltage source chip U2's positive pole end is connected with the power supply end of the main power chip of the switching power supply of peripheral hardware.
From the above description, the beneficial effects of the utility model are as follows:
through setting up field effect transistor Q1, electric capacity C1, triode Q2, phototriode U1B, emitting diode U1A and reference voltage source chip U2, realize the accurate control to output voltage through reference voltage source chip U2, when the output is unusual, it is to elementary turn-off field effect transistor Q1 to pass through phototriode U1B and emitting diode U1A conduction signal, start the guard action to switching power supply, when the unusual dismantlement, no signal feedback is to elementary, field effect transistor Q1 normally switches on, switching power supply normally works, thereby realize output overvoltage protection.
Further, the device further comprises a resistor R1 and a resistor R2, wherein one end of the resistor R1 is electrically connected with the drain electrode of the field effect transistor Q1, the other end of the resistor R1 is electrically connected with one end of the resistor R2, and the other end of the resistor R2 is electrically connected with one end of the capacitor C1.
As can be seen from the above description, the resistor R1 and the resistor R2 act as current limiting to charge the capacitor C1.
Further, the LED lamp further comprises a resistor R5, a resistor R6 and a resistor R7, wherein one end of the resistor R5 is electrically connected with one end of the resistor R6, one end of the resistor R7 and a voltage reference end of the reference voltage source chip U2 respectively, the other end of the resistor R6 is electrically connected with the other end of the resistor R7, an anode end of the reference voltage source chip U2 and a power supply end of a main power chip of a peripheral switching power supply respectively, and the other end of the resistor R5 is electrically connected with an anode of the LED U1A.
As can be seen from the above description, the resistors R5, R6 and R7 are provided for monitoring the output voltage.
Further, the LED lamp further comprises a resistor R3 and a resistor R4, wherein one end of the resistor R3 is electrically connected with the anode of the LED U1A and one end of the resistor R4 respectively, and the other end of the resistor R4 is electrically connected with the cathode of the LED U1A and the cathode end of the reference voltage source chip U2 respectively.
As can be seen from the above description, the resistor R3 and the resistor R4 are provided to limit the current of the light emitting diode U1A and the reference voltage source chip U2, so as to ensure that the light emitting diode U1A and the reference voltage source chip U2 operate within a reasonable range.
Further, the transistor further comprises a resistor R11, one end of the resistor R11 is electrically connected with the source electrode of the field effect transistor Q1, and the other end of the resistor R11 is electrically connected with one end of the capacitor C1, the emitter electrode of the triode Q2 and the collector electrode of the phototriode U1B respectively.
As can be seen from the above description, the resistor R11 is a pull-down resistor of the fet Q1, and discharges the GS capacitor of the fet Q1.
Further, the three-phase current collector further comprises a resistor R8, a resistor R9 and a resistor R10, wherein one end of the resistor R8 is electrically connected with the emitter of the triode Q2, the other end of the resistor R8 is electrically connected with one end of the capacitor C1, one end of the resistor R10 and the grid electrode of the field effect transistor Q1 respectively, the other end of the resistor R10 is electrically connected with one end of the resistor R9 and the collector electrode of the phototriode U1B respectively, and the other end of the resistor R9 is electrically connected with the base electrode of the triode Q2.
As can be seen from the above description, the resistor R8, the resistor R9 and the resistor R10 are provided to perform the current limiting function, so as to ensure that the transistor Q2 and the phototransistor U1B are not damaged.
Further, the LED lamp further comprises a voltage stabilizing tube ZD1, wherein the cathode of the voltage stabilizing tube ZD1 is electrically connected with one end of a capacitor C1, and the other end of the voltage stabilizing tube ZD1 is electrically connected with the other end of the capacitor C1, the collector of a triode Q2, the emitter of a phototriode U1B and the ground end of a main power chip of a peripheral switching power supply respectively.
As can be seen from the above description, the regulator ZD1 is provided to cooperate with the capacitor C1 so as to provide a stable voltage.
Referring to fig. 1, a first embodiment of the present utility model is as follows:
the utility model provides an output overvoltage control circuit of switching power supply, includes field effect transistor Q1 (model is CJ 3403), electric capacity C1 (capacitance value is 1 mu F), triode Q2 (model is FMMT 591), phototriode U1B, emitting diode U1A and reference voltage source chip U2, the grid of field effect transistor Q1 is connected with triode Q2's projecting pole, electric capacity C1's one end, phototriode U1B's one end electricity respectively, triode Q2's collecting electrode is connected with electric capacity C1's the other end, phototriode U1B's projecting pole and the ground terminal of the main power chip of peripheral hardware switching power supply respectively, the voltage reference end of reference voltage source chip U2 is connected with the positive pole electricity of emitting diode U1A, the negative pole of emitting diode U1A is connected with the negative pole end electricity of reference voltage source chip U2, the positive pole end of reference voltage source chip U2 is connected with the power supply end of the main power chip of peripheral hardware switching power supply.
The light emitting diode U1A and the phototransistor U1B form a finished photocoupler U1 (model LTV-1008-TP 1-G).
The resistor is characterized by further comprising a resistor R1 (the resistance value is 10k omega) and a resistor R2 (the resistance value is 10k omega), one end of the resistor R1 is electrically connected with the drain electrode of the field effect transistor Q1, the other end of the resistor R1 is electrically connected with one end of the resistor R2, and the other end of the resistor R2 is electrically connected with one end of the capacitor C1.
The LED lamp further comprises a resistor R5 (the resistance value is 4.99k omega), a resistor R6 (the resistance value is 3k omega) and a resistor R7 (the resistance value is NC), wherein one end of the resistor R5 is respectively and electrically connected with one end of the resistor R6, one end of the resistor R7 and a voltage reference end of the reference voltage source chip U2, the other end of the resistor R6 is respectively and electrically connected with the other end of the resistor R7, the anode end of the reference voltage source chip U2 and the power supply end of a main power chip of a peripheral switching power supply, and the other end of the resistor R5 is electrically connected with the anode of the LED U1A.
The LED lamp further comprises a resistor R3 (the resistance value is 500 omega) and a resistor R4 (the resistance value is 1k omega), one end of the resistor R3 is respectively and electrically connected with the anode of the LED U1A and one end of the resistor R4, and the other end of the resistor R4 is respectively and electrically connected with the cathode of the LED U1A and the cathode end of the reference voltage source chip U2.
The transistor further comprises a resistor R11 (the resistance value is 10k omega), one end of the resistor R11 is electrically connected with the source electrode of the field effect transistor Q1, and the other end of the resistor R11 is electrically connected with one end of the capacitor C1, the emitter electrode of the triode Q2 and the collector electrode of the phototriode U1B respectively.
Still include resistance R8 (resistance value is 10Ω), resistance R9 (resistance value is 10Ω) and resistance R10 (resistance value is 10kΩ), resistance R8's one end is connected with triode Q2's projecting pole electricity, resistance R8's the other end is connected with electric capacity C1's one end, resistance R10's one end and field effect transistor Q1's grid electricity respectively, resistance R10's the other end is connected with resistance R9's one end and phototriode U1B's collecting electrode electricity respectively, resistance R9's the other end is connected with triode Q2's base electricity.
The LED lamp further comprises a voltage stabilizing tube ZD1, wherein the cathode of the voltage stabilizing tube ZD1 is electrically connected with one end of a capacitor C1, and the other end of the voltage stabilizing tube ZD1 is electrically connected with the other end of the capacitor C1, the collector of a triode Q2, the emitter of a phototriode U1B and the ground end of a main power chip of a peripheral switching power supply respectively.
The working principle of the output overvoltage control circuit of the switching power supply is as follows:
when the switch power supply charges the capacitor C1 through the resistor R1 and the resistor R2, the field effect transistor Q1 is conducted when the voltage of the capacitor C1 reaches the starting voltage (about 3V) of the field effect transistor Q1, and when the field effect transistor Q1 is conducted, the whole main power loop is conducted, and the switch power supply works normally;
when the output voltage U0 of the port of the switching power supply rises and exceeds the designed nominal value, the output voltage U0 of the port of the switching power supply is divided by the resistors R5 and (R6// R7); the voltage of the Uref (i.e., the voltage reference terminal) of the reference voltage source chip U2 also increases, and when the Uref voltage of the reference voltage source chip U2 is greater than 2.5V, the reference voltage source chip U2 is saturated, and at this time, the light emitting diode U1A has a current flowing therethrough;
when the reference voltage source chip U2 is saturated and conducted, the light emitting diode U1A has current flowing through, and the phototriode U1B receives a light signal at the moment by utilizing the characteristic of the photoelectric coupler, and the phototriode U1B is conducted;
the phototransistor U1B is turned on, and the base-emitter voltage U of the triode Q2 is at this time be And the triode Q2 is conducted with the voltage less than-0.7V, when the triode Q2 is conducted, the capacitor C1 is discharged, when the voltage on the capacitor C1 is lower than the conducting voltage of the field effect tube Q1, the field effect tube Q1 is cut off, the main power chip does not form a loop to be closed, and then the switching power supply is closed, so that the protection function is started.
When the switching power supply works normally (namely, the output voltage U0 of the port of the switching power supply is lower than a set threshold value), the output voltage U0 of the port of the switching power supply is divided by the resistors R5 and (R6// R7); the Uref voltage of the reference voltage source chip U2 is less than 2.5V, the reference voltage source chip U2 is in a cut-off state at the moment, and when the reference voltage source chip U2 is in the cut-off state, the corresponding light emitting diode U1A and the corresponding phototriode U1B also have no current flowAt this time, the base-emitter voltage U of the corresponding transistor Q2 be The transistor Q2 is cut off, the capacitor C1 has no discharge loop, the field effect transistor Q1 is in a conducting state, and the switching power supply enters a protection state;
the output voltage is monitored in real time through the reference voltage source chip U2, when the output is over-voltage, the output is fed back to the primary turn-off field effect transistor Q1 through the photoelectric coupler U1, the protection effect on the switching power supply is started, when the abnormality is relieved, no signal is fed back to the primary, the field effect transistor Q1 is normally conducted, and the switching power supply works normally.
In summary, according to the output overvoltage control circuit of the switching power supply provided by the utility model, through the arrangement of the field effect transistor Q1, the capacitor C1, the triode Q2, the phototransistor U1B, the light emitting diode U1A and the reference voltage source chip U2, accurate monitoring of output voltage is realized through the reference voltage source chip U2, when output abnormality is that the signal is conducted to the primary turn-off field effect transistor Q1 through the phototransistor U1B and the light emitting diode U1A, the protection effect on the switching power supply is started, when abnormality is relieved, no signal is fed back to the primary, the field effect transistor Q1 is normally conducted, and the switching power supply normally works, so that output overvoltage protection is realized.
The foregoing description is only illustrative of the present utility model and is not intended to limit the scope of the utility model, and all equivalent changes made by the specification and drawings of the present utility model, or direct or indirect application in the relevant art, are included in the scope of the present utility model.

Claims (7)

1. The utility model provides an output overvoltage control circuit of switching power supply, its characterized in that includes field effect transistor Q1, electric capacity C1, triode Q2, phototriode U1B, emitting diode U1A and reference voltage source chip U2, the grid of field effect transistor Q1 is connected with triode Q2's projecting pole, electric capacity C1's one end, phototriode U1B's one end electricity respectively, triode Q2's collecting electrode is connected with electric capacity C1's the other end, phototriode U1B's projecting pole and the ground terminal of the main power chip of the switching power supply of peripheral hardware respectively, the voltage reference end of reference voltage source chip U2 is connected with emitting diode U1A's positive pole electricity, the negative pole of emitting diode U1A's negative pole is connected with reference voltage source chip U2's negative pole end electricity, reference voltage source chip U2's positive pole end is connected with the power supply end of the main power chip of the switching power supply of peripheral hardware.
2. The output overvoltage control circuit of claim 1, further comprising a resistor R1 and a resistor R2, wherein one end of the resistor R1 is electrically connected to the drain of the field effect transistor Q1, the other end of the resistor R1 is electrically connected to one end of the resistor R2, and the other end of the resistor R2 is electrically connected to one end of the capacitor C1.
3. The output overvoltage control circuit of claim 1, further comprising a resistor R5, a resistor R6, and a resistor R7, wherein one end of the resistor R5 is electrically connected to one end of the resistor R6, one end of the resistor R7, and a voltage reference end of the reference voltage source chip U2, the other end of the resistor R6 is electrically connected to the other end of the resistor R7, an anode end of the reference voltage source chip U2, and a power supply end of a main power chip of the external switching power supply, respectively, and the other end of the resistor R5 is electrically connected to an anode of the light emitting diode U1A.
4. The output overvoltage control circuit of claim 1, further comprising a resistor R3 and a resistor R4, wherein one end of the resistor R3 is electrically connected to the anode of the light emitting diode U1A and one end of the resistor R4, and the other end of the resistor R4 is electrically connected to the cathode of the light emitting diode U1A and the cathode of the reference voltage source chip U2, respectively.
5. The output overvoltage control circuit of claim 1, further comprising a resistor R11, wherein one end of the resistor R11 is electrically connected to the source of the field effect transistor Q1, and the other end of the resistor R11 is electrically connected to one end of the capacitor C1, the emitter of the transistor Q2, and the collector of the phototransistor U1B, respectively.
6. The output overvoltage control circuit of claim 1, further comprising a resistor R8, a resistor R9, and a resistor R10, wherein one end of the resistor R8 is electrically connected to the emitter of the transistor Q2, the other end of the resistor R8 is electrically connected to one end of the capacitor C1, one end of the resistor R10, and the gate of the field-effect transistor Q1, respectively, the other end of the resistor R10 is electrically connected to one end of the resistor R9 and the collector of the phototransistor U1B, respectively, and the other end of the resistor R9 is electrically connected to the base of the transistor Q2.
7. The output overvoltage control circuit of the switching power supply according to claim 1, further comprising a voltage regulator tube ZD1, wherein a cathode of the voltage regulator tube ZD1 is electrically connected with one end of the capacitor C1, and the other end of the voltage regulator tube ZD1 is electrically connected with the other end of the capacitor C1, a collector of the triode Q2, an emitter of the phototransistor U1B, and a ground terminal of a main power chip of the external switching power supply, respectively.
CN202320327956.7U 2023-02-27 2023-02-27 Output overvoltage control circuit of switching power supply Active CN219351270U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202320327956.7U CN219351270U (en) 2023-02-27 2023-02-27 Output overvoltage control circuit of switching power supply

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202320327956.7U CN219351270U (en) 2023-02-27 2023-02-27 Output overvoltage control circuit of switching power supply

Publications (1)

Publication Number Publication Date
CN219351270U true CN219351270U (en) 2023-07-14

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Application Number Title Priority Date Filing Date
CN202320327956.7U Active CN219351270U (en) 2023-02-27 2023-02-27 Output overvoltage control circuit of switching power supply

Country Status (1)

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CN (1) CN219351270U (en)

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