CN109888738A - Self-locking output overvoltage protection circuit and voltage output system - Google Patents
Self-locking output overvoltage protection circuit and voltage output system Download PDFInfo
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- CN109888738A CN109888738A CN201910075742.3A CN201910075742A CN109888738A CN 109888738 A CN109888738 A CN 109888738A CN 201910075742 A CN201910075742 A CN 201910075742A CN 109888738 A CN109888738 A CN 109888738A
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- 238000005070 sampling Methods 0.000 claims abstract description 32
- 239000003990 capacitor Substances 0.000 claims description 44
- 239000003381 stabilizer Substances 0.000 claims description 38
- 230000005611 electricity Effects 0.000 claims description 11
- 230000003111 delayed effect Effects 0.000 description 14
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- 230000009286 beneficial effect Effects 0.000 description 2
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- 230000000977 initiatory effect Effects 0.000 description 2
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- 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
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- Dc-Dc Converters (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The present invention discloses a kind of self-locking output overvoltage protection circuit and voltage output system, including the first input unit, second input unit, sampling unit, partial pressure unit, filter unit, self-locking type switch unit and control unit, first input unit is for inputting first voltage, first input unit is electrically connected with sampling unit, second input unit is for inputting second voltage, second input unit is electrically connected with sampling unit, sampling unit is electrically connected with partial pressure unit, partial pressure unit is electrically connected with filter unit, filter unit is electrically connected with self-locking type switch unit, self-locking type switch unit is electrically connected with control unit, control unit is used to control the shutdown or conducting of power supply.The present invention when occur input terminal voltage it is excessively high when, then can star over-voltage protecting function, avoid burning out the electronic component of rear end connection, avoid the occurrence of the problem of burning out circuit board because of overtension, while improving the stability and reliability of power circuit.
Description
Technical field
The present invention relates to voltage output system regions, more particularly to a kind of self-locking output overvoltage protection circuit and electricity
Pressure output system.
Background technique
Inverse-excitation type (Flyback) transformer is also known as single-ended flyback or " Buck-Boost " converter.Because its output end exists
Energy is obtained when primary side winding disconnects power supply so gaining the name.Inverse excitation type converter is simple with its circuit structure, low in cost and deep
Liked by numerous Developmental Engineer.Flyback transformer is suitble to small-power power and various power supply adaptors.But flyback
The design difficulty of formula converter is the design of transformer, full negative especially in low input because of wide input voltage range
Transformer can work in continuous current mode under the conditions of load, and transformer can work again under high input voltage, light-load conditions
In discontinuous current mode.
However, PFC VCC and LLC VCC are by circuit of reversed excitation in traditional flyback+PFC+LLC circuit framework
VCC power supply, the VCC winding of originally LLC transformer will not use, and the VCC over-voltage protecting function of LLC circuit is just without making
It is too high at voltage value when LLC electric power output voltage overvoltage protection, back-end circuit element is burnt out, circuit board will be also burnt out when serious,
Reduce the stability and reliability of power circuit.
Summary of the invention
The purpose of the present invention is overcoming shortcoming in the prior art, a kind of self-locking output over-voltage protection electricity is provided
Road and voltage output system, when occur input terminal voltage it is excessively high when, then can star over-voltage protecting function, avoid burning out
The electronic component of rear end connection, avoids the occurrence of the problem of burning out circuit board because of overtension, while improving the steady of power circuit
Qualitative and reliability.
The purpose of the present invention is achieved through the following technical solutions:
A kind of self-locking output overvoltage protection circuit, comprising: the first input unit, the second input unit, sampling unit,
Partial pressure unit, filter unit, self-locking type switch unit and control unit, the input terminal of first input unit is for inputting
The output end of first voltage, first input unit is electrically connected with the input terminal of the sampling unit, and second input is single
The input terminal of member is for inputting second voltage, the output end of second input unit and the input terminal electricity of the sampling unit
Connection, the output end of the sampling unit is electrically connected with the input terminal of the partial pressure unit, the output end of the partial pressure unit and
The output end of the filter unit is electrically connected, the input terminal of the output end of the filter unit and the self-locking type switch unit
Electrical connection, the output end of the self-locking type switch unit are electrically connected with the input terminal of described control unit, described control unit
Output end is used to control the shutdown or conducting of power supply.
First input unit includes voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2, voltage-stabiliser tube ZD3 in one of the embodiments,
And diode D3, the cathode of the voltage-stabiliser tube ZD1 are electrically connected with the first voltage, the anode of the voltage-stabiliser tube ZD1, which is connected, to be connected
It is electrically connected after meeting the voltage-stabiliser tube ZD2, the voltage-stabiliser tube ZD3 and the diode D3 with the input terminal of the sampling unit.
Second input unit includes voltage-stabiliser tube ZD4 and diode D2, the pressure stabilizing in one of the embodiments,
The cathode of pipe ZD4 is electrically connected with the second voltage, and the anode of the voltage-stabiliser tube ZD4 and the anode of the diode D2 are electrically connected
It connects, the cathode of the diode D2 is electrically connected with the input terminal of the sampling unit.
The sampling unit includes resistance R3 and capacitor C2, the first end of the resistance R3 in one of the embodiments,
It is electrically connected respectively with first input unit and second input unit, the second end of the resistance R3 and the capacitor
The first end of C2 is electrically connected, the second end ground connection of the capacitor C2.
The partial pressure unit includes diode D1 and resistance R2, the sun of the diode D1 in one of the embodiments,
Pole is electrically connected with the second end of the resistance R3, and the cathode of the diode D1 is electrically connected with the first end of the resistance R2, institute
State the second end ground connection of resistance R2.
In one of the embodiments, the filter unit include a capacitor C1, the first end of the capacitor C1 respectively with
The input terminal of the self-locking type switch unit and the output end electrical connection of the partial pressure unit, the second termination of the capacitor C1
Ground.
The self-locking type switch unit includes triode Q1 and triode Q2, three pole in one of the embodiments,
The base stage of pipe Q1 is electrically connected with the cathode of the diode D1, the base of the collector of the triode Q1 and the triode Q2
Pole electrical connection, the emitter ground connection of the triode Q1, the emitter of the triode Q2 and the input terminal of described control unit
Electrical connection, the collector of the triode Q2 are electrically connected with the cathode of the diode D1.
The self-locking type switch unit further includes resistance R1 in one of the embodiments, one end of the resistance R1 with
The base stage of the triode Q2 is electrically connected, and the other end of the resistance R1 is electrically connected with the emitter of the triode Q2.
Described control unit includes photoelectrical coupler and triode Q7, the photoelectric coupling in one of the embodiments,
The secondary of device is electrically connected with the output end of the self-locking type switch unit, primary and the triode of the photoelectrical coupler
The base stage of Q7 is electrically connected, and the emitter of the triode Q7 is used for output voltage signal.
A kind of voltage output system, including self-locking output overvoltage protection circuit described in any of the above one.
The present invention compared with the prior art the advantages of and have the beneficial effect that:
The present invention is a kind of self-locking output overvoltage protection circuit and voltage output system, by setting sampling unit, is divided
Pressure unit, filter unit and self-locking type switch unit then pass through partial pressure when sampling unit collected overtension
Unit and filter unit give the self-locking type switch unit Continuity signal, to drag down the power supply signal of control unit, and then make
The photoelectrical coupler cut-off in control unit is obtained, and then causes control unit not work, and make entire voltage output system not
Work.When occur input terminal voltage it is excessively high when, then can star over-voltage protecting function, avoid burning out the electricity of rear end connection
Sub- component avoids the occurrence of the problem of burning out circuit board because of overtension, while improving the stability of power circuit and reliable
Property.
Detailed description of the invention
In order to illustrate the technical solution of the embodiments of the present invention more clearly, below will be to needed in the embodiment
Attached drawing is briefly described, it should be understood that the following drawings illustrates only certain embodiments of the present invention, therefore is not to be seen as
It is the restriction to range, it for those of ordinary skill in the art, without creative efforts, can be with
Other relevant attached drawings are obtained according to these attached drawings.
Fig. 1 is the functional block diagram of the self-locking output overvoltage protection circuit of an embodiment of the present invention；
Fig. 2 is the circuit diagram of self-locking output overvoltage protection circuit shown in FIG. 1；
Fig. 3 is the circuit diagram of the voltage output system of an embodiment of the present invention；
Fig. 4 is the circuit diagram of the booting delay circuit of voltage output system shown in Fig. 3.
Specific embodiment
To facilitate the understanding of the present invention, a more comprehensive description of the invention is given in the following sections with reference to the relevant attached drawings.In attached drawing
Give better embodiment of the invention.But the invention can be realized in many different forms, however it is not limited to this
Embodiment described in text.On the contrary, the purpose of providing these embodiments is that making to the disclosure understanding
It is more thorough and comprehensive.
It should be noted that it can directly on the other element when element is referred to as " being fixed on " another element
Or there may also be elements placed in the middle.When an element is considered as " connection " another element, it, which can be, is directly connected to
To another element or it may be simultaneously present centering elements.Term as used herein " vertical ", " horizontal ", " left side ",
" right side " and similar statement for illustrative purposes only, are not meant to be the only embodiment.
Unless otherwise defined, all technical and scientific terms used herein and belong to technical field of the invention
The normally understood meaning of technical staff it is identical.Term as used herein in the specification of the present invention is intended merely to retouch
State the purpose of specific embodiment, it is not intended that in the limitation present invention.Term " and or " used herein includes one
Or any and all combinations of multiple relevant listed items.
Primary circuit does not have over-voltage protecting function, and when certain reason causes output overvoltage, output voltage values can be risen to very
Height is easy to burn out the element in back-end circuit in this way, in order to protect back-end circuit element not burn out because of power supply over-voltage, therefore
Increase this output over-voltage protection latching circuit, it, can be by output voltage overvoltage region after increasing output over-voltage protection latching circuit
Control is in allowed limits.Power supply is not protected when the application mainly solves power supply output overvoltage, and output overvoltage voltage value is too high
Back-end circuit element is burnt out, can solve output over-voltage protection problem after increasing this circuit.
Referring to Fig. 1, a kind of self-locking output overvoltage protection circuit, comprising: the input of the first input unit 100, second is single
Member 200, sampling unit 300, partial pressure unit 400, filter unit 500, self-locking type switch unit 600 and control unit 700, institute
The input terminal of the first input unit is stated for inputting first voltage, the output end of first input unit and the sampling are single
The input terminal electrical connection of member, the input terminal of second input unit are used to input second voltage, second input unit
Output end is electrically connected with the input terminal of the sampling unit, the input of the output end of the sampling unit and the partial pressure unit
End electrical connection, the output end of the partial pressure unit are electrically connected with the output end of the filter unit, the output of the filter unit
End is electrically connected with the input terminal of the self-locking type switch unit, and the output end of the self-locking type switch unit and the control are single
The input terminal electrical connection of member, the output end of described control unit are used to control the shutdown or conducting of power supply.
It should be noted that first input unit 100 is used to obtain the voltage of HVCC, second input unit
200 for obtaining the voltage of VPWR；The sampling unit 300 is used for the voltage using two input units；The partial pressure unit
400 pairs of voltage using unit input divides；The filter unit 500 for realizing input voltage filter effect；Institute
Self-locking type switch unit 600 is stated for realizing overvoltage protection；Described control unit 700 receives for controlling entire circuit
Overvoltage protection signal, and then the output of voltage is truncated.In this way, by setting sampling unit, partial pressure unit, filter unit and from
Latching switch unit, when sampling unit collected overtension, then by partial pressure unit and filter unit to described
Self-locking type switch unit Continuity signal, so that the power supply signal of control unit is dragged down, so that the photoelectricity in control unit
Coupler cut-off, and then cause control unit not work, and entire voltage output system is not worked.
It should be noted that referring to Fig. 2, first input unit includes voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2, pressure stabilizing
Pipe ZD3 and diode D3, the cathode of the voltage-stabiliser tube ZD1 are electrically connected with the first voltage, the anode of the voltage-stabiliser tube ZD1
The input terminal electricity after the voltage-stabiliser tube ZD2, the voltage-stabiliser tube ZD3 and the diode D3 with the sampling unit is connected in series
Connection.In this way, can realize preliminary partial pressure to the high voltage of HVCC, and can also guarantee defeated by the way that multiple voltage-stabiliser tubes are arranged
The voltage entered is more stable.
Referring to Fig. 2, second input unit includes voltage-stabiliser tube ZD4 and diode D2, the yin of the voltage-stabiliser tube ZD4
Pole is electrically connected with the second voltage, and the anode of the voltage-stabiliser tube ZD4 is electrically connected with the anode of the diode D2, and described two
The cathode of pole pipe D2 is electrically connected with the input terminal of the sampling unit.In this way, by the way that multiple voltage-stabiliser tubes are arranged, it can be to VPWR
High voltage realize preliminary partial pressure, and can also guarantee input voltage it is more stable.
Referring to Fig. 2, the sampling unit includes resistance R3 and capacitor C2, the first end of the resistance R3 respectively with institute
State the first input unit and second input unit electrical connection, the second end of the resistance R3 and the first of the capacitor C2
End electrical connection, the second end ground connection of the capacitor C2.In this way, can be adopted to two input voltages by the way that resistance R3 is arranged
Sample, and can be with superimposed voltage signal.
It should be noted that referring to Fig. 2, the partial pressure unit includes diode D1 and resistance R2, the diode D1
Anode be electrically connected with the second end of the resistance R3, the cathode of the diode D1 and the first end of the resistance R2 are electrically connected
It connects, the second end ground connection of the resistance R2.In this way, by setting diode D1 and resistance R2, rectification is may be implemented in diode
Effect, resistance R2 and resistance R3 can form partial pressure, realize partial pressure effect.
Referring to Fig. 2, the filter unit include a capacitor C1, the first end of the capacitor C1 respectively with it is described self-locking
The input terminal of formula switch unit and the electrical connection of the output end of the partial pressure unit, the second end ground connection of the capacitor C1.In this way,
By the way that capacitor C1 is arranged, the effect of filtering may be implemented.
Referring to Fig. 2, the self-locking type switch unit includes triode Q1 and triode Q2, the base of the triode Q1
Pole is electrically connected with the cathode of the diode D1, and the collector of the triode Q1 is electrically connected with the base stage of the triode Q2,
The emitter of the triode Q1 is grounded, and the emitter of the triode Q2 is electrically connected with the input terminal of described control unit, institute
The collector for stating triode Q2 is electrically connected with the cathode of the diode D1.In this way, passing through setting triode Q1 and triode
Q2, it is ensured that when over-voltage, self-locking effect may be implemented, guarantee that over-voltage protecting function can be realized steadily.
It should be noted that referring to Fig. 2, the self-locking type switch unit further includes resistance R1, the one of the resistance R1
End is electrically connected with the base stage of the triode Q2, and the other end of the resistance R1 is electrically connected with the emitter of the triode Q2.
It should be noted that described control unit includes photoelectrical coupler and triode Q7, time of the photoelectrical coupler
Grade is electrically connected with the output end of the self-locking type switch unit, the primary and the base of the triode Q7 of the photoelectrical coupler
The emitter of pole electrical connection, the triode Q7 is used for output voltage signal.
The course of work: defeated when+92V or+24V voltage increase when certain reason causes LLC power supply output over-voltage protection
+ 92V the voltage of over-voltage is added on resistance R3 through voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2, voltage-stabiliser tube ZD3, diode D3 out, makes resistance
R3 both end voltage increases, and+24V the voltage of output overvoltage after diode D2, is also added on resistance R3, is also made through voltage-stabiliser tube ZD4
Resistance R3 both end voltage increases, and after resistance R3 both end voltage increases, divides through diode D1, resistance R2, after capacitor C1 filtering
After being added to the B pole tension raising of the pole the B triode Q1 of triode Q1, the pole C of triode Q1 and the conducting of the pole E, the B of triode Q2
Pole tension decline, the pole C of triode Q2 and the conducting of the pole E, photoelectrical coupler U4A IC power supply are dragged down, photoelectrical coupler U4A is cut
It does not only work, photoelectrical coupler U4B is also switched off work, the B pole tension decline of triode Q7, and triode Q7 ends work, PFC
VCC and LLC VCC stops power supply, and power supply is in guard mode without output, thus achieve the purpose that overvoltage protection, overvoltage protection
The size of value, can be by adjusting voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2, voltage-stabiliser tube ZD3, and the pressure stabilizing value of voltage-stabiliser tube ZD4 is realized,
Triode Q1, triode Q2 form a self-locking route.
It is thus desirable to explanation, primary circuit does not have over-voltage protecting function, defeated when certain reason causes output overvoltage
Voltage value can rise to very high out, be easy to burn out the element in back-end circuit in this way, in order to protect back-end circuit element not because
Power supply over-voltage and burn out, therefore increase this output over-voltage protection latching circuit, can be with after increasing output over-voltage protection latching circuit
In allowed limits by the control of output voltage overvoltage region.Within the allowable range by the control of output overvoltage value, overpressure value can be with
It adjusts according to actual needs.
Referring to Fig. 3, a kind of voltage output system, including self-locking output over-voltage protection described in any of the above one
Circuit.It is appreciated that original power supply, in low pressure booting moment, PFC inductance can issue a sound of " tittering ", reason is that power supply is being opened
Machine moment, PFC VCC and LLC VCC power simultaneously, start simultaneously, when PFC voltage rises in normal range (NR) not yet,
The starting of LLC power supply electrifying, pfc circuit load at this time is very heavy, and machine power is very big, and PFC inductance can issue a sound of " tittering ", produces
Biggish noise has been given birth to, while also will reduce the stability of power circuit over time to the biggish load of circuit bring.
Therefore, in an embodiment, the voltage output system further include booting delay circuit, the booting delay circuit with it is described
The electrical connection of self-locking output overvoltage protection circuit.
It is appreciated that the purpose of this circuit system is LLC VCC power supply to be postponed, after making pfc circuit first working properly,
LLC circuit is switched on work again, and a sound of " tittering " would not be issued by playing electromechanical source PFC inductance in this way, and booting abnormal sound is eliminated, problem
It is improved.
A kind of booting delay circuit, comprising: the first partial pressure unit, delay unit, delayed startup switch, the second partial pressure are single
Member and conducting switch unit, the collection terminal of first partial pressure unit are used to be electrically connected with the output end of external linear voltage-stablizer,
The output end of first partial pressure unit is electrically connected with the input terminal of the delay unit, the output end of the delay unit with
The input terminal electrical connection of the delayed startup switch, the output end of the delayed startup switch and second partial pressure unit
Input terminal electrical connection, the output end of second partial pressure unit is electrically connected with the input terminal of the conducting switch unit, described to lead
The output end of logical switch unit with the VCC of external LLC circuit for being electrically connected.It should be noted that first partial pressure unit
For sampling and being divided to input voltage；The delay unit for realizing delayed startup effect；The delayed startup
Switch the conducting for realizing delay；Second partial pressure unit is for realizing the partial pressure of conducting, and input voltage signal is to leading
In logical switch unit；It is powered after the conducting switching means conductive for the VCC to LLC circuit.
In this way, by setting delay unit, delayed startup switch and conducting switch unit, outside delay unit receives
It when the input voltage in portion, charges to the capacitor of its own, so that voltage can not be once in delayed startup switch
Reach conducting voltage, with the completion of charging, conducting delayed startup switch after voltage increases immediately, and then but also conducting is opened
It closes unit and realizes on state, finally realize the effect of delayed startup, so that playing electromechanical source PFC inductance will not
" tittering " sound is issued, avoids issuing noise when power initiation, booting abnormal sound is eliminated, reduces the load occurred when starting,
And improve the stability of power circuit.
It should be noted that referring to Fig. 4, first partial pressure unit includes resistance R114 and resistance R112, the electricity
Resistance R112 first end be electrically connected with the output end of the external linear voltage-stablizer, the second end of the resistance R112 with it is described
The first end of resistance R114 is electrically connected, the second end ground connection of the resistance R114.In this way, passing through setting resistance R114 and resistance
The effect of partial pressure may be implemented in R112.
Referring to Fig. 4, the delay unit includes capacitor C386 and capacitor C384, the first end of the capacitor C386 with
The output end of first partial pressure unit is electrically connected, the second end ground connection of the capacitor C386, the both ends point of the capacitor C384
Both ends not with the capacitor C386 are connected in parallel.In this way, by setting capacitor C386 and capacitor C384, when the mistake in starting
Cheng Zhong needs to charge to capacitor C386 and capacitor C384, at this point, preventing the triode of delay switch unit from timely
Conducting the triode in delay switch unit could be connected after capacitor C386 and capacitor C384 charge, so that realization is prolonged
The effect of Shi Qidong, guarantee are not in the sound of " tittering ".
It should be noted that delayed startup switch includes first switch tube, the control terminal of the first switch tube with
The delay unit output end electrical connection, the first end of the first switch tube is electrically connected with second partial pressure unit, described
The second end of first switch tube is grounded.In this embodiment, the first switch tube is triode Q14, the triode Q14's
Base stage is electrically connected with the delay unit output end, the input of the collector of the triode Q14 and second partial pressure unit
End electrical connection, the emitter ground connection of the triode Q14.
It should be noted that referring to Fig. 4, second partial pressure unit includes resistance R115 and resistance R117, the electricity
Resistance R115 first end be electrically connected with the first end of the first switch tube, the second end of the resistance R115 respectively with it is described
The input terminal electrical connection of the first end of resistance R117 and the conducting switch unit, the second end of the resistance R117 and institute
State another input terminal electrical connection of conducting switch unit.
It should be noted that the conducting switch unit includes second switch, the control terminal of the second switch with
The output end of second partial pressure unit is electrically connected, and the first end of the second switch is defeated with first partial pressure unit
Enter end electrical connection, the second end of the second switch is used for output voltage.In the present embodiment, the second switch is
Triode Q13, the base stage of the triode Q13 are electrically connected with the output end of second partial pressure unit, the triode Q13
Emitter be electrically connected with the input terminal of first partial pressure unit, the collector of the triode Q13 and the external LLC
The VCC of circuit is electrically connected.
It should be noted that referring to Fig. 4, the conducting switch unit further includes capacitor C38, the of the capacitor C38
One end is electrically connected with the base stage of the triode Q13, the second end ground connection of the capacitor C38.
When work:
One stable 16.5V or so PFC is come out by the homopolar linear pressure stabilizing of E of triode Q7 from external input voltage
VCC voltage is added to the pole B of triode Q14 after resistance R114 and resistance R112 partial pressure, to the B of triode Q14 extremely on electricity
Hold C386 and capacitor C384 charging, the purpose that capacitor C386 and capacitor C384 charge is triode Q14 conducting to be postponed, and is needed
How long is delay, then adjusts the value of capacitor C386, capacitor C384, resistance R114 and resistance R112 to determine, as capacitor C386
After capacitor C384 charging, the B pole tension of triode Q14 rises, the pole C of triode Q14 and the conducting of the pole E, triode Q14's
The decline of E pole tension, by the voltage pull-down after resistance R115 and resistance R117 partial pressure, the B pole tension of triode Q13 can also decline,
When the B pole tension of triode Q13 drops to certain numerical value, triode Q13 conducting is powered after conducting to LLC VCC, in this way
Delay circuit reaches delay LLC VCC power supply purpose.
In this way, PFC VCC and LLC VCC power simultaneously on original circuit, power supply moment when low pressure is switched on
The sound for having " tittering " applies for that this circuit purpose is LLC VCC power supply to be postponed, allows PFC circuit first to work, pfc circuit work
After normal, LLC circuit works again.Existing power supply circuit PFC VCC and LLC VCC power simultaneously, it may appear that power supply low pressure
PFC inductance issues a sound of " tittering " when the machine of rising, and after the delay LLC VCC of the application power supply, booting moment is just sent out without abnormal sound
Out.
By setting delay unit, delayed startup switch and conducting switch unit, when delay unit receives the defeated of outside
It when entering voltage, charges to the capacitor of its own, so that voltage can not once reach and lead in delayed startup switch
Be powered pressure, with the completion of charging, conducting delayed startup switch after voltage increases immediately, and then but also conducting switch unit
It realizes on state, finally realizes the effect of delayed startup, so that playing electromechanical source PFC inductance will not issue
" tittering " sound avoids issuing noise when power initiation, eliminates booting abnormal sound, reduces the load occurred when starting, and
Improve the stability of power circuit.
The present invention compared with the prior art the advantages of and have the beneficial effect that:
The present invention is a kind of self-locking output overvoltage protection circuit and voltage output system, by setting sampling unit, is divided
Pressure unit, filter unit and self-locking type switch unit then pass through partial pressure when sampling unit collected overtension
Unit and filter unit give the self-locking type switch unit Continuity signal, to drag down the power supply signal of control unit, and then make
The photoelectrical coupler cut-off in control unit is obtained, and then causes control unit not work, and make entire voltage output system not
Work.When occur input terminal voltage it is excessively high when, then can star over-voltage protecting function, avoid burning out the electricity of rear end connection
Sub- component avoids the occurrence of the problem of burning out circuit board because of overtension, while improving the stability of power circuit and reliable
Property.
Only several embodiments of the present invention are expressed for embodiment described above, and the description thereof is more specific and detailed, but
It cannot be construed as a limitation to the scope of the present invention.It should be pointed out that for the ordinary skill people of this field
For member, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to the present invention
Protection scope.Therefore, the scope of protection of the patent of the invention shall be subject to the appended claims.
Claims (10)
1. a kind of self-locking output overvoltage protection circuit characterized by comprising the first input unit, is adopted the second input unit
The input terminal of sample unit, partial pressure unit, filter unit, self-locking type switch unit and control unit, first input unit is used
In input first voltage, the output end of first input unit is electrically connected with the input terminal of the sampling unit, and described second
The input terminal of input unit is for inputting second voltage, the input of the output end and the sampling unit of second input unit
End electrical connection, the output end of the sampling unit are electrically connected with the input terminal of the partial pressure unit, the output of the partial pressure unit
End is electrically connected with the output end of the filter unit, the input of the output end of the filter unit and the self-locking type switch unit
End electrical connection, the output end of the self-locking type switch unit are electrically connected with the input terminal of described control unit, described control unit
Output end be used to control the shutdown or conducting of power supply.
2. self-locking output overvoltage protection circuit according to claim 1, which is characterized in that the first input unit packet
Include voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2, voltage-stabiliser tube ZD3 and diode D3, the cathode of the voltage-stabiliser tube ZD1 and first voltage electricity
Connection, the anode of the voltage-stabiliser tube ZD1 be connected in series after the voltage-stabiliser tube ZD2, the voltage-stabiliser tube ZD3 and the diode D3 with
The input terminal of the sampling unit is electrically connected.
3. self-locking output overvoltage protection circuit according to claim 1, which is characterized in that the second input unit packet
Voltage-stabiliser tube ZD4 and diode D2 are included, the cathode of the voltage-stabiliser tube ZD4 is electrically connected with the second voltage, the voltage-stabiliser tube ZD4's
Anode is electrically connected with the anode of the diode D2, and the input terminal of the cathode and the sampling unit of the diode D2 is electrically connected
It connects.
4. self-locking output overvoltage protection circuit according to claim 1, which is characterized in that the sampling unit includes electricity
Resistance R3 and capacitor C2, the first end of the resistance R3 are electrically connected with first input unit and second input unit respectively
It connects, the second end of the resistance R3 is electrically connected with the first end of the capacitor C2, the second end ground connection of the capacitor C2.
5. self-locking output overvoltage protection circuit according to claim 4, which is characterized in that the partial pressure unit includes two
Pole pipe D1 and resistance R2, the anode of the diode D1 are electrically connected with the second end of the resistance R3, the yin of the diode D1
Pole is electrically connected with the first end of the resistance R2, the second end ground connection of the resistance R2.
6. self-locking output overvoltage protection circuit according to claim 1, which is characterized in that the filter unit includes one
Capacitor C1, the output with the input terminal of the self-locking type switch unit and the partial pressure unit respectively of the first end of the capacitor C1
End electrical connection, the second end ground connection of the capacitor C1.
7. self-locking output overvoltage protection circuit according to claim 5, which is characterized in that the self-locking type switch unit
Including triode Q1 and triode Q2, the base stage of the triode Q1 is electrically connected with the cathode of the diode D1, three pole
The collector of pipe Q1 is electrically connected with the base stage of the triode Q2, the emitter ground connection of the triode Q1, the triode Q2
Emitter be electrically connected with the input terminal of described control unit, the cathode of the collector of the triode Q2 and the diode D1
Electrical connection.
8. self-locking output overvoltage protection circuit according to claim 7, which is characterized in that the self-locking type switch unit
Further include resistance R1, one end of the resistance R1 is electrically connected with the base stage of the triode Q2, the other end of the resistance R1 with
The emitter of the triode Q2 is electrically connected.
9. self-locking output overvoltage protection circuit according to claim 1, which is characterized in that described control unit includes light
The secondary of electric coupler and triode Q7, the photoelectrical coupler are electrically connected with the output end of the self-locking type switch unit, institute
The primary for stating photoelectrical coupler is electrically connected with the base stage of the triode Q7, and the emitter of the triode Q7 is used for output voltage
Signal.
10. a kind of voltage output system, which is characterized in that exported including self-locking described in any one of claim 1~9
Overvoltage crowbar.
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 |
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| Publication Number | Publication Date |
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| CN109888738A true CN109888738A (en) | 2019-06-14 |
| CN109888738B CN109888738B (en) | 2024-04-19 |
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| CN201910075742.3A Active CN109888738B (en) | 2019-01-25 | 2019-01-25 | Self-locking output overvoltage protection circuit and voltage output system |
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| CN (1) | CN109888738B (en) |
| WO (1) | WO2020151362A1 (en) |
Cited By (2)
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| 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 |
| WO2020151362A1 (en) * | 2019-01-25 | 2020-07-30 | 惠州三华工业有限公司 | Self-locking output overvoltage protection circuit and voltage output system |
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Also Published As
| Publication number | Publication date |
|---|---|
| CN109888738B (en) | 2024-04-19 |
| WO2020151362A1 (en) | 2020-07-30 |
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