CN109888738B - Self-locking output overvoltage protection circuit and voltage output system - Google Patents
Self-locking output overvoltage protection circuit and voltage output system Download PDFInfo
- Publication number
- CN109888738B CN109888738B CN201910075742.3A CN201910075742A CN109888738B CN 109888738 B CN109888738 B CN 109888738B CN 201910075742 A CN201910075742 A CN 201910075742A CN 109888738 B CN109888738 B CN 109888738B
- Authority
- CN
- China
- Prior art keywords
- unit
- voltage
- electrically connected
- self
- input
- 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
- 238000005070 sampling Methods 0.000 claims abstract description 33
- 238000001914 filtration Methods 0.000 claims abstract description 22
- 239000003990 capacitor Substances 0.000 claims description 36
- 230000000087 stabilizing effect Effects 0.000 claims description 18
- 230000000694 effects Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a self-locking output overvoltage protection circuit and a voltage output system, which comprise a first input unit, a second input unit, a sampling unit, a voltage division unit, a filtering unit, a self-locking switch unit and a control unit, wherein the first input unit is used for inputting a first voltage, the first input unit is electrically connected with the sampling unit, the second input unit is used for inputting a second voltage, the second input unit is electrically connected with the sampling unit, the sampling unit is electrically connected with the voltage division unit, the voltage division unit is electrically connected with the filtering unit, the filtering unit is electrically connected with the self-locking switch unit, the self-locking switch unit is electrically connected with the control unit, and the control unit is used for controlling the turn-off or turn-on of a power supply. When the voltage of the input end is too high, the overvoltage protection function can be started, the electronic components connected with the rear end are prevented from being burnt out, the problem that the circuit board is burnt out due to the too high voltage is avoided, and meanwhile, the stability and the reliability of the power supply circuit are improved.
Description
Technical Field
The invention relates to the field of voltage output systems, in particular to a self-locking output overvoltage protection circuit and a voltage output system.
Background
Flyback transformers are also known as single-ended Flyback or "Buck-Boost" converters. The output end of the transformer gets energy when the primary winding is disconnected from the power supply, so the transformer is named. The flyback converter has simple circuit structure and low cost and is deeply favored by development engineers. The flyback transformer is suitable for low-power supplies and various power adapters. However, the design difficulty of flyback converters is the design of transformers because of the wide input voltage range, especially when the transformer is operated in continuous current mode at low input voltage, full load conditions, and discontinuous current mode at high input voltage, light load conditions.
However, in the traditional flyback+PFC+LLC circuit architecture, PFC VCC and LLC VCC are supplied through VCC of a flyback circuit, the VCC winding of an original LLC transformer is not used, the VCC overvoltage protection function of the LLC circuit is not available, the voltage value is too high when the LLC power supply output voltage is subjected to overvoltage protection, the back-end circuit element is burnt out, the circuit board is burnt out in severe cases, and the stability and reliability of the power supply circuit are reduced.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a self-locking output overvoltage protection circuit and a voltage output system, when the voltage of an input end is too high, the overvoltage protection function can be started, the electronic components connected with the rear end are prevented from being burnt out, the problem that a circuit board is burnt out due to the too high voltage is avoided, and meanwhile, the stability and the reliability of a power supply circuit are improved.
The aim of the invention is realized by the following technical scheme:
A self-locking output overvoltage protection circuit, comprising: the sampling device comprises a first input unit, a second input unit, a sampling unit, a voltage dividing unit, a filtering unit, a self-locking switch unit and a control unit, wherein the input end of the first input unit is used for inputting first voltage, the output end of the first input unit is electrically connected with the input end of the sampling unit, the input end of the second input unit is used for inputting second voltage, the output end of the second input unit is electrically connected with the input end of the sampling unit, the output end of the sampling unit is electrically connected with the input end of the voltage dividing unit, the output end of the voltage dividing unit is electrically connected with the output end of the filtering unit, the output end of the filtering unit is electrically connected with the input end of the self-locking switch unit, the output end of the self-locking switch unit is electrically connected with the input end of the control unit, and the output end of the control unit is used for controlling the turn-off or turn-on of a power supply.
In one embodiment, the first input unit includes a voltage regulator ZD1, a voltage regulator ZD2, a voltage regulator ZD3, and a diode D3, where a cathode of the voltage regulator ZD1 is electrically connected to the first voltage, and an anode of the voltage regulator ZD1 is serially connected to the voltage regulator ZD2, the voltage regulator ZD3, and the diode D3 and then electrically connected to an input end of the sampling unit.
In one embodiment, the second input unit includes a voltage regulator ZD4 and a diode D2, where a cathode of the voltage regulator ZD4 is electrically connected to the second voltage, an anode of the voltage regulator ZD4 is electrically connected to an anode of the diode D2, and a cathode of the diode D2 is electrically connected to an input terminal of the sampling unit.
In one embodiment, the sampling unit includes a resistor R3 and a capacitor C2, wherein a first end of the resistor R3 is electrically connected to the first input unit and the second input unit, a second end of the resistor R3 is electrically connected to a first end of the capacitor C2, and a second end of the capacitor C2 is grounded.
In one embodiment, the voltage dividing unit includes a diode D1 and a resistor R2, the anode of the diode D1 is electrically connected to the second end of the resistor R3, the cathode of the diode D1 is electrically connected to the first end of the resistor R2, and the second end of the resistor R2 is grounded.
In one embodiment, the filtering unit includes a capacitor C1, a first end of the capacitor C1 is electrically connected to the input end of the self-locking switch unit and the output end of the voltage dividing unit, and a second end of the capacitor C1 is grounded.
In one embodiment, the self-locking switch unit comprises a triode Q1 and a triode Q2, wherein the base electrode of the triode Q1 is electrically connected with the cathode of the diode D1, the collector electrode of the triode Q1 is electrically connected with the base electrode of the triode Q2, the emitter electrode of the triode Q1 is grounded, the emitter electrode of the triode Q2 is electrically connected with the input end of the control unit, and the collector electrode of the triode Q2 is electrically connected with the cathode of the diode D1.
In one embodiment, the self-locking switch unit further includes a resistor R1, one end of the resistor R1 is electrically connected to the base of the triode Q2, and the other end of the resistor R1 is electrically connected to the emitter of the triode Q2.
In one embodiment, the control unit includes a photo coupler and a triode Q7, wherein a secondary of the photo coupler is electrically connected with an output end of the self-locking switch unit, a primary of the photo coupler is electrically connected with a base electrode of the triode Q7, and an emitter of the triode Q7 is used for outputting a voltage signal.
A voltage output system comprising the self-locking output overvoltage protection circuit of any one of the above.
Compared with the prior art, the invention has the following advantages:
The invention relates to a self-locking output overvoltage protection circuit and a voltage output system, wherein a sampling unit, a voltage dividing unit, a filtering unit and a self-locking switch unit are arranged, when the voltage acquired by the sampling unit is too high, the voltage dividing unit and the filtering unit are used for conducting signals to the self-locking switch unit, so that the power supply signal of a control unit is lowered, a photoelectric coupler in the control unit is cut off, the control unit is disabled, and the whole voltage output system is disabled. When the voltage of the input end is too high, the overvoltage protection function can be started, the electronic components connected with the rear end are prevented from being burnt out, the problem that a circuit board is burnt out due to the too high voltage is avoided, and meanwhile, the stability and the reliability of a power circuit are improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without invasive effort for a person skilled in the art.
FIG. 1 is a functional block diagram of a self-locking output overvoltage protection circuit according to an embodiment of the present invention;
FIG. 2 is a circuit diagram of the self-locking output overvoltage protection circuit shown in FIG. 1;
FIG. 3 is a circuit diagram of a voltage output system according to an embodiment of the invention;
Fig. 4 is a circuit diagram of a power-on delay circuit of the voltage output system shown in fig. 3.
Detailed Description
In order that the invention may be readily understood, a more complete description of the invention will be rendered by reference to the appended drawings. The drawings illustrate preferred embodiments of the invention. This 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 "fixed 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 and are not meant to be the only embodiment.
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 herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
The original circuit has no overvoltage protection function, when the output overvoltage is caused by a certain reason, the output voltage value can rise to be very high, so that components on the back-end circuit are easy to burn out, in order to protect the components of the back-end circuit from being burnt out due to the overvoltage of a power supply, the output overvoltage protection self-locking circuit is added, and after the output overvoltage protection self-locking circuit is added, the overvoltage range of the output voltage can be controlled within an allowable range. The application mainly solves the problem that the power supply is not protected when the power supply outputs overvoltage, the output overvoltage voltage value is too high to burn out the circuit element at the rear end, and the problem of output overvoltage protection can be solved after the circuit is added.
Referring to fig. 1, a self-locking output overvoltage protection circuit includes: the self-locking type power supply comprises a first input unit 100, a second input unit 200, a sampling unit 300, a voltage dividing unit 400, a filtering unit 500, a self-locking type switch unit 600 and a control unit 700, wherein the input end of the first input unit is used for inputting first voltage, the output end of the first input unit is electrically connected with the input end of the sampling unit, the input end of the second input unit is used for inputting second voltage, the output end of the second input unit is electrically connected with the input end of the sampling unit, the output end of the sampling unit is electrically connected with the input end of the voltage dividing unit, the output end of the voltage dividing unit is electrically connected with the output end of the filtering unit, the output end of the filtering unit is electrically connected with the input end of the self-locking type switch unit, the output end of the self-locking type switch unit is electrically connected with the input end of the control unit, and the output end of the control unit is used for controlling the turn-off or turn-on of a power supply.
Note that, the first input unit 100 is configured to obtain a voltage of HVCC, and the second input unit 200 is configured to obtain a voltage of VPWR; the sampling unit 300 is used for taking the voltages of two input units; the voltage dividing unit 400 divides the voltage input by the adoption unit; the filtering unit 500 is configured to implement a filtering effect of an input voltage; the self-locking switch unit 600 is used for realizing overvoltage protection; the control unit 700 is used for controlling the whole circuit and receiving an overvoltage protection signal so as to cut off the output of the voltage. Therefore, when the voltage acquired by the sampling unit is too high, the self-locking switch unit is conducted through the voltage dividing unit and the filtering unit, so that the power supply signal of the control unit is lowered, the photoelectric coupler in the control unit is cut off, the control unit is disabled, and the whole voltage output system is disabled.
It should be noted that, referring to fig. 2, the first input unit includes a voltage regulator ZD1, a voltage regulator ZD2, a voltage regulator ZD3 and a diode D3, where a cathode of the voltage regulator ZD1 is electrically connected with the first voltage, and an anode of the voltage regulator ZD1 is electrically connected with the input end of the sampling unit after being serially connected with the voltage regulator ZD2, the voltage regulator ZD3 and the diode D3. Therefore, by arranging the plurality of voltage stabilizing tubes, preliminary voltage division can be realized on the high voltage of the HVCC, and the input voltage can be ensured to be more stable.
Referring to fig. 2, the second input unit includes a voltage regulator ZD4 and a diode D2, wherein a cathode of the voltage regulator ZD4 is electrically connected with the second voltage, an anode of the voltage regulator ZD4 is electrically connected with an anode of the diode D2, and a cathode of the diode D2 is electrically connected with an input end of the sampling unit. Therefore, by arranging the voltage stabilizing tubes, preliminary voltage division can be realized on the high voltage of the VPWR, and the input voltage can be ensured to be more stable.
Referring to fig. 2, the sampling unit includes a resistor R3 and a capacitor C2, wherein a first end of the resistor R3 is electrically connected to the first input unit and the second input unit, a second end of the resistor R3 is electrically connected to a first end of the capacitor C2, and a second end of the capacitor C2 is grounded. In this way, by setting the resistor R3, two input voltages can be sampled and voltage signals can be superimposed.
It should be noted that, referring to fig. 2, the voltage dividing unit includes a diode D1 and a resistor R2, an anode of the diode D1 is electrically connected to the second end of the resistor R3, a cathode of the diode D1 is electrically connected to the first end of the resistor R2, and a second end of the resistor R2 is grounded. Therefore, the diode D1 and the resistor R2 are arranged, the diode can achieve rectifying effect, the resistor R2 and the resistor R3 can form partial voltage, and the partial voltage effect is achieved.
Referring to fig. 2, the filtering unit includes a capacitor C1, a first end of the capacitor C1 is electrically connected to an input end of the self-locking switch unit and an output end of the voltage dividing unit, and a second end of the capacitor C1 is grounded. Thus, by providing the capacitor C1, the effect of filtering can be achieved.
Referring to fig. 2, the self-locking switch unit includes a triode Q1 and a triode Q2, wherein a base electrode of the triode Q1 is electrically connected with a cathode of the diode D1, a collector electrode of the triode Q1 is electrically connected with a base electrode of the triode Q2, an emitter electrode of the triode Q1 is grounded, an emitter electrode of the triode Q2 is electrically connected with an input end of the control unit, and a collector electrode of the triode Q2 is electrically connected with a cathode of the diode D1. Therefore, by arranging the triode Q1 and the triode Q2, the self-locking effect can be realized when overvoltage is ensured, and the overvoltage protection function can be stably realized.
It should be noted that, referring to fig. 2, the self-locking switch unit further includes a resistor R1, one end of the resistor R1 is electrically connected to the base electrode of the triode Q2, and the other end of the resistor R1 is electrically connected to the emitter electrode of the triode Q2.
It should be noted that, the control unit includes a photo coupler and a triode Q7, a secondary of the photo coupler is electrically connected with an output end of the self-locking switch unit, a primary of the photo coupler is electrically connected with a base electrode of the triode Q7, and an emitter of the triode Q7 is used for outputting a voltage signal.
The working process comprises the following steps: when the voltage of +92V or +24V is increased when the LLC power supply outputs overvoltage protection due to a certain reason, the +92V voltage of the overvoltage is increased, the +92V voltage is applied to a resistor R3 through a voltage stabilizing tube ZD1, a voltage stabilizing tube ZD2 and a diode D3, the voltage at two ends of the resistor R3 is increased, the +24V voltage of the overvoltage is also applied to the resistor R3 after passing through a voltage stabilizing tube ZD4 and a diode D2, the voltage at two ends of the resistor R3 is increased, the voltage is divided by a diode D1 and is applied to a C electrode and E electrode of a triode Q1 after being filtered by a capacitor C1, the B electrode voltage of the B electrode triode Q1 is increased, the C electrode and the E electrode of the triode Q1 are conducted, the voltage of the B pole of the triode Q2 is reduced, the C pole and the E pole of the triode Q2 are conducted, the power supply of the photoelectric coupler U4A IC is pulled down, the photoelectric coupler U4A is cut off and does not work, the photoelectric coupler U4B is also cut off and works, the voltage of the B pole of the triode Q7 is reduced, the triode Q7 is cut off and works, PFC and LLC VCC stop supplying power, the power supply is not output, and the power supply is in a protection state, so that the purpose of overvoltage protection is achieved, the overvoltage protection value can be achieved by adjusting the voltage stabilizing value of the voltage stabilizing tube ZD1, the voltage stabilizing tube ZD2, the voltage stabilizing tube ZD3 and the voltage stabilizing value of the voltage stabilizing tube ZD4, and the triode Q1 and the triode Q2 form a self-locking circuit.
Therefore, it should be noted that the original circuit has no overvoltage protection function, when the output overvoltage is caused by a certain reason, the output voltage value can rise to be very high, so that the components on the back-end circuit are easy to burn out, in order to protect the back-end circuit components from being burned out due to the overvoltage of a power supply, the output overvoltage protection self-locking circuit is added, and after the output overvoltage protection self-locking circuit is added, the overvoltage range of the output voltage can be controlled within the allowable range. And controlling the output overvoltage value within an allowable range, wherein the overvoltage value can be adjusted according to actual needs.
Referring to fig. 3, a voltage output system includes the self-locking output overvoltage protection circuit described in any one of the above. It can be understood that the original power supply can emit a sound of "" in the low-voltage starting moment, because the power supply is started simultaneously when the PFC VCC and the LLC VCC are powered on at the starting moment, when the PFC voltage does not rise to the normal range yet, the LLC power supply is powered on and started, at the moment, the PFC circuit is heavy in load and high in starting power, the PFC inductance can emit a sound of "in" to generate larger noise, and simultaneously, larger load is brought to the circuit, and the stability of the power supply circuit is reduced over time. Therefore, in one embodiment, the voltage output system further includes a start-up delay circuit, and the start-up delay circuit is electrically connected with the self-locking output overvoltage protection circuit.
It can be understood that the purpose of the circuit system is to delay LLC VCC power supply, so that the PFC circuit works normally before the LLC circuit is started up, thus the PFC inductance of the starting power supply can not generate a sound of "clean" and the problem of starting abnormal sound is solved.
A power-on delay circuit comprising: the device comprises a first voltage dividing unit, a delay starting switch, a second voltage dividing unit and a conduction switch unit, wherein the acquisition end of the first voltage dividing unit is used for being electrically connected with the output end of an external linear voltage stabilizer, the output end of the first voltage dividing unit is electrically connected with the input end of the delay unit, the output end of the delay unit is electrically connected with the input end of the delay starting switch, the output end of the delay starting switch is electrically connected with the input end of the second voltage dividing unit, the output end of the second voltage dividing unit is electrically connected with the input end of the conduction switch unit, and the output end of the conduction switch unit is used for being electrically connected with VCC of an external LLC circuit. The first voltage dividing unit is used for sampling and dividing the input voltage; the delay unit is used for realizing the effect of delay starting; the delay starting switch is used for realizing delayed conduction; the second voltage dividing unit is used for realizing the voltage division of conduction and inputting a voltage signal into the conduction switch unit; and the conducting switch unit is used for supplying power to VCC of the LLC circuit after being conducted.
Therefore, by arranging the delay unit, the delay starting switch and the conducting switch unit, when the delay unit receives external input voltage, the capacitor of the delay unit is charged, so that the voltage in the delay starting switch cannot reach the conducting voltage once, the delay starting switch is conducted after the voltage rises immediately along with the completion of charging, the conducting switch unit is further enabled to realize a conducting state, and the effect of delay starting is finally realized, so that PFC inductance of a starting power supply can not emit 'over' sound, noise is prevented from being emitted when the power supply is started, abnormal starting noise is eliminated, load appearing during starting is reduced, and the stability of the power supply circuit is improved.
It should be noted that, referring to fig. 4, the first voltage dividing unit includes a resistor R114 and a resistor R112, a first end of the resistor R112 is electrically connected to the output end of the external linear voltage regulator, a second end of the resistor R112 is electrically connected to the first end of the resistor R114, and a second end of the resistor R114 is grounded. Thus, by providing the resistor R114 and the resistor R112, the voltage dividing effect can be achieved.
Referring to fig. 4, the delay unit includes a capacitor C386 and a capacitor C384, a first end of the capacitor C386 is electrically connected to an output end of the first voltage dividing unit, a second end of the capacitor C386 is grounded, and two ends of the capacitor C384 are respectively connected in parallel with two ends of the capacitor C386. Therefore, by setting the capacitor C386 and the capacitor C384, when the capacitor C386 and the capacitor C384 need to be charged in the starting process, at this time, the triode of the delay switch unit cannot be timely conducted, and when the capacitor C386 and the capacitor C384 are charged, the triode in the delay switch unit can be conducted, so that the effect of delay starting is achieved, and the ' noise of the ' noise ' is avoided.
It should be noted that, the delay starting switch includes a first switch tube, the control end of the first switch tube is electrically connected with the output end of the delay unit, the first end of the first switch tube is electrically connected with the second voltage division unit, and the second end of the first switch tube is grounded. In this embodiment, the first switch tube is a triode Q14, a base electrode of the triode Q14 is electrically connected with the output end of the delay unit, a collector electrode of the triode Q14 is electrically connected with the input end of the second voltage division unit, and an emitter electrode of the triode Q14 is grounded.
It should be noted that, referring to fig. 4, the second voltage dividing unit includes a resistor R115 and a resistor R117, a first end of the resistor R115 is electrically connected to a first end of the first switch tube, a second end of the resistor R115 is electrically connected to a first end of the resistor R117 and an input end of the conducting switch unit, and a second end of the resistor R117 is electrically connected to another input end of the conducting switch unit.
It should be noted that, the on-switch unit includes a second switch tube, a control end of the second switch tube is electrically connected with an output end of the second voltage division unit, a first end of the second switch tube is electrically connected with an input end of the first voltage division unit, and a second end of the second switch tube is used for outputting voltage. In this embodiment, the second switching tube is a triode Q13, a base electrode of the triode Q13 is electrically connected with an output end of the second voltage division unit, an emitter electrode of the triode Q13 is electrically connected with an input end of the first voltage division unit, and a collector electrode of the triode Q13 is electrically connected with VCC of the external LLC circuit.
It should be noted that referring to fig. 4, the on-switch unit further includes a capacitor C38, a first end of the capacitor C38 is electrically connected to the base of the transistor Q13, and a second end of the capacitor C38 is grounded.
When in operation, the device comprises:
The input voltage from outside is stabilized by E polar line of triode Q7 and is a stable 16.5V PFC VCC voltage, divide voltage and add to triode Q14's B pole through resistance R114 and resistance R112, charge electric capacity C386 and electric capacity C384 on triode Q14's B pole, electric capacity C386 and electric capacity C384 charge purpose delay triode Q14 switches on, how long time is needed, then adjust electric capacity C386, electric capacity C384, resistance R114 and resistance R112's value determines, after electric capacity C386 and electric capacity C384 charges, triode Q14's B pole voltage rises, triode Q14's C pole and E pole switch on, triode Q14's E pole voltage drops, draw down the voltage after the electric capacity of dividing voltage of resistance R115 and resistance R117, triode Q13's B pole voltage also drops, when triode Q13's B pole voltage drops to certain numerical value, triode Q13 switches on, supply power to VCC after switching on, delay circuit like this, reach the purpose of delaying power supply VCC.
Thus, on the original circuit, PFC VCC and LLC VCC are simultaneously supplied, and the power supply instantaneously generates a sound of' when the power supply is started at low voltage, so that the aim of the circuit is to delay LLC VCC supply, so that the PFC circuit works first, and then the LLC circuit works after the PFC circuit works normally. The PFC VCC and LLC VCC of the existing power supply circuit are supplied simultaneously, and the PFC inductance emits a sound of 'gouging' when the power supply is started up at a low voltage.
Through setting up delay element, delay starting switch and switch-on unit, when delay element received the external input voltage, charge its self electric capacity, thereby make the unable switch-on voltage that reaches of voltage in the delay starting switch, along with the completion of charging, the voltage is risen immediately after switch-on delay starting switch, and then also make switch-on unit realize the conducting state, the effect of time delay start has finally been realized, thereby can make the power PFC inductance can not send out "and send out" sound, avoid sending out the noise when the power starts, eliminate the start abnormal sound, reduce the load that appears when starting, and improve power circuit's stability.
Compared with the prior art, the invention has the following advantages:
The invention relates to a self-locking output overvoltage protection circuit and a voltage output system, wherein a sampling unit, a voltage dividing unit, a filtering unit and a self-locking switch unit are arranged, when the voltage acquired by the sampling unit is too high, the voltage dividing unit and the filtering unit are used for conducting signals to the self-locking switch unit, so that the power supply signal of a control unit is lowered, a photoelectric coupler in the control unit is cut off, the control unit is disabled, and the whole voltage output system is disabled. When the voltage of the input end is too high, the overvoltage protection function can be started, the electronic components connected with the rear end are prevented from being burnt out, the problem that a circuit board is burnt out due to the too high voltage is avoided, and meanwhile, the stability and the reliability of a power circuit are improved.
The above embodiments represent only a few embodiments of the present invention, which are described in more detail and detail, but are not to be construed as limiting the scope of the present invention. It should be noted that it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit of the invention, which are within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (10)
1. A self-locking output overvoltage protection circuit, comprising: the self-locking type power supply comprises a first input unit, a second input unit, a sampling unit, a voltage dividing unit, a filtering unit, a self-locking type switch unit and a control unit, wherein the input end of the first input unit is used for inputting first voltage, the output end of the first input unit is electrically connected with the input end of the sampling unit, the input end of the second input unit is used for inputting second voltage, the output end of the second input unit is electrically connected with the input end of the sampling unit, the output end of the sampling unit is electrically connected with the input end of the voltage dividing unit, the output end of the voltage dividing unit is electrically connected with the output end of the filtering unit, the output end of the filtering unit is electrically connected with the input end of the self-locking type switch unit, and the output end of the self-locking type switch unit is electrically connected with the input end of the control unit.
2. The self-locking output overvoltage protection circuit according to claim 1, wherein the first input unit comprises a voltage stabilizing tube ZD1, a voltage stabilizing tube ZD2, a voltage stabilizing tube ZD3 and a diode D3, wherein a cathode of the voltage stabilizing tube ZD1 is electrically connected with the first voltage, and an anode of the voltage stabilizing tube ZD1 is electrically connected with an input end of the sampling unit after being connected with the voltage stabilizing tube ZD2, the voltage stabilizing tube ZD3 and the diode D3 in series.
3. The self-locking output overvoltage protection circuit according to claim 1, wherein the second input unit comprises a voltage regulator ZD4 and a diode D2, the cathode of the voltage regulator ZD4 is electrically connected with the second voltage, the anode of the voltage regulator ZD4 is electrically connected with the anode of the diode D2, and the cathode of the diode D2 is electrically connected with the input terminal of the sampling unit.
4. The self-locking output overvoltage protection circuit according to claim 1, wherein the sampling unit comprises a resistor R3 and a capacitor C2, a first end of the resistor R3 is electrically connected to the first input unit and the second input unit, a second end of the resistor R3 is electrically connected to a first end of the capacitor C2, and a second end of the capacitor C2 is grounded.
5. The self-locking output overvoltage protection circuit according to claim 4, wherein the voltage dividing unit comprises a diode D1 and a resistor R2, an anode of the diode D1 is electrically connected to the second end of the resistor R3, a cathode of the diode D1 is electrically connected to the first end of the resistor R2, and the second end of the resistor R2 is grounded.
6. The self-locking output overvoltage protection circuit according to claim 1, wherein the filter unit comprises a capacitor C1, a first end of the capacitor C1 is electrically connected to the input end of the self-locking switch unit and the output end of the voltage dividing unit, and a second end of the capacitor C1 is grounded.
7. The self-locking output overvoltage protection circuit according to claim 5, wherein the self-locking switch unit comprises a triode Q1 and a triode Q2, wherein a base electrode of the triode Q1 is electrically connected with a cathode of the diode D1, a collector electrode of the triode Q1 is electrically connected with a base electrode of the triode Q2, an emitter electrode of the triode Q1 is grounded, an emitter electrode of the triode Q2 is electrically connected with an input end of the control unit, and a collector electrode of the triode Q2 is electrically connected with a cathode of the diode D1.
8. The self-locking output overvoltage protection circuit according to claim 7, wherein the self-locking switch unit further comprises a resistor R1, one end of the resistor R1 is electrically connected with the base electrode of the triode Q2, and the other end of the resistor R1 is electrically connected with the emitter electrode of the triode Q2.
9. The self-locking output overvoltage protection circuit according to claim 1, wherein the control unit comprises a photo coupler and a triode Q7, a secondary of the photo coupler is electrically connected with an output end of the self-locking switch unit, a primary of the photo coupler is electrically connected with a base of the triode Q7, and an emitter of the triode Q7 is used for outputting a voltage signal.
10. A voltage output system comprising a self-locking output overvoltage protection circuit according to any one of claims 1 to 9.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910075742.3A CN109888738B (en) | 2019-01-25 | 2019-01-25 | Self-locking output overvoltage protection circuit and voltage output system |
| PCT/CN2019/121353 WO2020151362A1 (en) | 2019-01-25 | 2019-11-27 | Self-locking output overvoltage protection circuit and voltage output system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910075742.3A CN109888738B (en) | 2019-01-25 | 2019-01-25 | Self-locking output overvoltage protection circuit and voltage output system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109888738A CN109888738A (en) | 2019-06-14 |
| CN109888738B true CN109888738B (en) | 2024-04-19 |
Family
ID=66927046
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910075742.3A Active CN109888738B (en) | 2019-01-25 | 2019-01-25 | Self-locking output overvoltage protection circuit and voltage output system |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN109888738B (en) |
| WO (1) | WO2020151362A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109888738B (en) * | 2019-01-25 | 2024-04-19 | 惠州三华工业有限公司 | Self-locking output overvoltage protection circuit and voltage output system |
| CN110518546A (en) * | 2019-09-19 | 2019-11-29 | 山东超越数控电子股份有限公司 | A kind of self-locking power supply overvoltage protection circuit and implementation method based on triode |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103326325A (en) * | 2013-06-05 | 2013-09-25 | 广州凯盛电子科技有限公司 | Short-circuit and low-voltage protective circuit of output of switching power source |
| CN104218519A (en) * | 2013-05-30 | 2014-12-17 | 海洋王（东莞）照明科技有限公司 | Overvoltage protection circuit and lamp |
| WO2015018093A1 (en) * | 2013-08-09 | 2015-02-12 | 吉瑞高新科技股份有限公司 | Charger with overvoltage and overcurrent protection and protection method therefor |
| WO2015051688A1 (en) * | 2013-10-09 | 2015-04-16 | 珠海格力电器股份有限公司 | Protective circuit for input voltage of switch power source |
| CN209419199U (en) * | 2019-01-25 | 2019-09-20 | 惠州三华工业有限公司 | Self-locking output overvoltage protection circuit and voltage output system |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100550561C (en) * | 2006-11-21 | 2009-10-14 | 青岛海信电器股份有限公司 | Power protecting circuit |
| CN203166467U (en) * | 2013-03-20 | 2013-08-28 | 向智勇 | Overvoltage protection circuit |
| CN204992541U (en) * | 2015-09-25 | 2016-01-20 | 新宝电机(东莞)有限公司 | Switch power -supply overvoltage protecting circuit |
| CN207021660U (en) * | 2017-05-27 | 2018-02-16 | 河南思维自动化设备股份有限公司 | Electrical source input overvoltage protection and output overvoltage protection circuit |
| CN109888738B (en) * | 2019-01-25 | 2024-04-19 | 惠州三华工业有限公司 | Self-locking output overvoltage protection circuit and voltage output system |
-
2019
- 2019-01-25 CN CN201910075742.3A patent/CN109888738B/en active Active
- 2019-11-27 WO PCT/CN2019/121353 patent/WO2020151362A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104218519A (en) * | 2013-05-30 | 2014-12-17 | 海洋王（东莞）照明科技有限公司 | Overvoltage protection circuit and lamp |
| CN103326325A (en) * | 2013-06-05 | 2013-09-25 | 广州凯盛电子科技有限公司 | Short-circuit and low-voltage protective circuit of output of switching power source |
| WO2015018093A1 (en) * | 2013-08-09 | 2015-02-12 | 吉瑞高新科技股份有限公司 | Charger with overvoltage and overcurrent protection and protection method therefor |
| WO2015051688A1 (en) * | 2013-10-09 | 2015-04-16 | 珠海格力电器股份有限公司 | Protective circuit for input voltage of switch power source |
| CN209419199U (en) * | 2019-01-25 | 2019-09-20 | 惠州三华工业有限公司 | Self-locking output overvoltage protection circuit and voltage output system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109888738A (en) | 2019-06-14 |
| WO2020151362A1 (en) | 2020-07-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109888738B (en) | Self-locking output overvoltage protection circuit and voltage output system | |
| CN115498883A (en) | Circuit for supplying power to switching power supply control circuit based on auxiliary winding | |
| CN110099234B (en) | Power supply starting device and television | |
| US11289939B2 (en) | Power supply apparatus and standby power source for controller for vehicle | |
| CN217935460U (en) | Power supply circuit of flyback converter | |
| WO2017088566A1 (en) | Protection circuit and control device for brushless dc motor | |
| CN216160989U (en) | Starting circuit and starting device | |
| CN113659819B (en) | Power-down delay control method and control circuit | |
| CN213693478U (en) | Isolated voltage conversion circuit, control circuit thereof and electronic packaging piece | |
| US20160205732A1 (en) | Drive circuit for illuminating device and illuminating device having the drive circuit | |
| CN102027666A (en) | Overvoltage limitation in a chopping converter | |
| CN114709109A (en) | Relay slow discharge driving circuit | |
| CN111009958B (en) | Power supply control circuit | |
| CN109067207B (en) | Self-sufficient power supply circuit for flyback power converter | |
| CN109450222B (en) | Switching power supply control IC energy supply circuit | |
| CN101931317A (en) | Power supply start control circuit and power supply | |
| CN220421641U (en) | Boost circuit and power module applying same | |
| CN220235008U (en) | Pulse lamp control circuit, pulse lamp and refrigerator | |
| CN218449865U (en) | Circuit for supplying power to switching power supply control circuit based on auxiliary winding | |
| CN116960911B (en) | Current-limiting protection circuit, power supply circuit and energy storage power supply | |
| CN218217095U (en) | Power supply circuit | |
| CN218569818U (en) | Booster circuit, power module, and electronic device | |
| CN212323706U (en) | Charging pile switching power supply fault protection circuit and charging pile power supply | |
| CN220775397U (en) | Flyback power supply circuit, circuit board and electronic equipment | |
| CN217282714U (en) | Direct current motor driving power supply based on PSR technology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |