CN104348365B - Control circuit and method, supply unit - Google Patents
Control circuit and method, supply unit Download PDFInfo
- Publication number
- CN104348365B CN104348365B CN201410614004.9A CN201410614004A CN104348365B CN 104348365 B CN104348365 B CN 104348365B CN 201410614004 A CN201410614004 A CN 201410614004A CN 104348365 B CN104348365 B CN 104348365B
- Authority
- CN
- China
- Prior art keywords
- circuit
- control
- synchronous rectification
- switching power
- voltage
- 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
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
- H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
- H02M3/33592—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer
-
- 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
- H02H7/125—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 for rectifiers
-
- 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
Abstract
The present invention provides a kind of control circuit and method, supply unit.The control circuit includes：Acquisition module, when reverse surge current occurs in the primary side for the switching power circuit when circuit of synchronous rectification, obtains the voltage signal that the reverse surge current is produced；Module is kept, for when the voltage signal is more than default first voltage threshold value, the first control signal persistently to be exported in default first time period；Control module, the secondary-side switch pipe of the switching power circuit for controlling the shut-off circuit of synchronous rectification according to first control signal.It using the technical scheme of the embodiment of the present invention, can effectively suppress the electric current reverse surge in the switching power circuit of circuit of synchronous rectification, can effectively protect the security of the Switching Power Supply of circuit of synchronous rectification.Using the supply unit of this control circuit, the security and reliability of power supply can be effectively improved.
Description
Technical field
The present embodiments relate to power technique fields, more particularly to a kind of control circuit and method, supply unit.
Background technology
In power technique fields, circuit of synchronous rectification is a kind of circuit applied widely.
The switching power circuit of traditional circuit of synchronous rectification generally realizes rectification using diode, but diode
Conduction loss is higher, causes to use the Switching Power Supply operating efficiency of the rectification circuit of diode relatively low.Later, people gradually adopted
Metal-oxide-semicondutor-FET (Metal-Oxide-Semiconductor Field-Effect-
Transistor；Hereinafter referred to as MOSFET or metal-oxide-semiconductor) etc. switching tube substitute traditional diode and realize synchronous rectification.Such as Fig. 1
It show the circuit diagram of the switching power circuit of existing circuit of synchronous rectification.Switching tube Q1-Q4 opens for circuit of synchronous rectification
The switching tube of the primary side of powered-down source circuit.VIN+ and VIN- is the input of the primary side of the switching power circuit of circuit of synchronous rectification
End.Switching tube Q5-Q8 is the switching tube of the secondary of the switching power circuit of circuit of synchronous rectification.Switching tube way of realization is not only
One, for example, can be realized by diode, triode, metal-oxide-semiconductor, enter in Fig. 1 so that switching tube Q1-Q8 uses metal-oxide-semiconductor as an example
Row explanation.Referring to Fig. 1, VOUT+ and VOUT- is the output end of secondary here.T1 is the switching power circuit of circuit of synchronous rectification
In primary and secondary side isolating transformer, the first electric capacity C1 for circuit of synchronous rectification switching power circuit primary side input
Filter capacitor.As shown in figure 1, being replaced in the switching tube Q5-Q8 of the secondary of the switching power circuit of circuit of synchronous rectification using metal-oxide-semiconductor
For the diode in conventional art, conduction loss is greatly reduced, the efficiency of power supply is improved.But after metal-oxide-semiconductor conducting, electric current
It is two-way flow.When input power generation low-resistance is anti-drop, it is reverse that synchronous rectification can produce very big output
Current surge, easily damages metal-oxide-semiconductor, therefore there is reliability hidden danger using the Switching Power Supply of the circuit of synchronous rectification of metal-oxide-semiconductor.
For the reliability of the Switching Power Supply that strengthens circuit of synchronous rectification, prior art is used in primary side switch pipe rectification list
The voltage input end increase counnter attack diode or metal-oxide-semiconductor of member, for when conducting electric current is reverse, rapidly switching off reverse electricity
Stream, effectively to protect the Switching Power Supply of circuit of synchronous rectification.
In process of the present invention is realized, inventor has found that at least there are the following problems in the prior art：Prior art is used
In the original edge voltage input increase counnter attack diode or metal-oxide-semiconductor of the switching power circuit of circuit of synchronous rectification, although one
Determine to prevent that power supply produces input reverse current surge when input power generation low-resistance is anti-drop in degree.But
Counnter attack diode or metal-oxide-semiconductor are the increase in, the increase of system cost can be brought；It is additionally, since counnter attack diode or metal-oxide-semiconductor
It in the main circuit for being provided in the switching power circuit of circuit of synchronous rectification, can also increase the power attenuation of circuit, reduce power supply
Operating efficiency.
The content of the invention
The embodiment of the present invention provides a kind of control circuit and method, supply unit, to solve to prevent electricity in the prior art
The circuit increase system cost of reverse surge and the defect of power consumption are flowed, can be on the premise of cost and power consumption not be increased, effectively
Ground, which is realized, suppresses reverse current surge.
The embodiment of the present invention provides a kind of control circuit, including：
Acquisition module, when reverse surge current occurs in the primary side for the switching power circuit when circuit of synchronous rectification, is obtained
The voltage signal for taking the reverse surge current to produce；
Module is kept, for when the voltage signal is more than default first voltage threshold value, in the default very first time
The first control signal is persistently exported in section；
Control module, for being controlled to turn off the switch power supply of the circuit of synchronous rectification according to first control signal
The secondary-side switch pipe on road.
The embodiment of the present invention provides a kind of supply unit, includes the switching power circuit of circuit of synchronous rectification, as described above
Control circuit.
The embodiment of the present invention also provides a kind of control method for suppressing reverse current surge, including：
When reverse surge current occurs in the primary side of the switching power circuit of circuit of synchronous rectification, the reverse surge is obtained
The voltage signal that electric current is produced；
When the voltage signal is more than default first voltage threshold value, one is persistently exported in default first time period
First control signal；
According to first control signal, the secondary-side switch of the switching power circuit of the control shut-off circuit of synchronous rectification
Pipe.
Control circuit and method, the supply unit of the embodiment of the present invention, by reverse during reverse current surge to occurring
The voltage signal that surge current is produced is detected, so that the switching tube of the secondary to the switching power circuit of circuit of synchronous rectification
Turn off, restrained effectively electric current reverse surge, can effectively protect the peace in the Switching Power Supply of circuit of synchronous rectification
Quan Xing.Thus it is guaranteed that the reliability of power supply.Simultaneously using the technical scheme of inventive embodiments, additionally it is possible to ensure the work of power supply
Make efficiency.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
There is the accompanying drawing used required in technology description to be briefly described, it should be apparent that, drawings in the following description are this hairs
Some bright embodiments, for those of ordinary skill in the art, without having to pay creative labor, can be with
Other accompanying drawings are obtained according to these accompanying drawings.
Fig. 1 is the circuit diagram of the switching power circuit of existing circuit of synchronous rectification；
Fig. 2 is the structural representation for the control circuit that the embodiment of the present invention one is provided；
Fig. 3 is the structural representation of the control circuit of the offer of the present embodiment two；
Fig. 4 implements the structural representation of three supply units provided for the present invention；
Fig. 5 is the circuit diagram for the supply unit that the embodiment of the present invention four is provided；
Fig. 6 is a kind of signal sequence oscillogram of circuit shown in Fig. 5；
Fig. 7 is the flow chart of the control method for the suppression reverse current surge that the embodiment of the present invention five is provided；
Fig. 8 is the flow chart of the control method for the suppression reverse current surge that the embodiment of the present invention six is provided.
Embodiment
To make the purpose, technical scheme and advantage of the embodiment of the present invention clearer, below in conjunction with the embodiment of the present invention
In accompanying drawing, the technical scheme in the embodiment of the present invention is clearly and completely described, it is clear that described embodiment is
A part of embodiment of the present invention, rather than whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art
The every other embodiment obtained under the premise of creative work is not made, belongs to the scope of protection of the invention.
Fig. 2 is the structural representation for the control circuit that the embodiment of the present invention one is provided.As shown in Fig. 2 the control of the present embodiment
Circuit processed, including：Acquisition module 10, holding module 11, control module 12.
Wherein acquisition module 10 is used for when reverse surge current occurs in the primary side of the switching power circuit of circuit of synchronous rectification
When, obtain the voltage signal that reverse surge current is produced.Module 11 is kept to be used for when voltage signal is more than default first voltage
During threshold value, the first control signal is persistently exported in default first time period.Control module 12 is used to be believed according to the first control
Number, turn off the secondary-side switch pipe of the switching power circuit of circuit of synchronous rectification.
Specifically, when the input generation low-resistance of the Switching Power Supply of circuit of synchronous rectification is anti-drop, circuit of synchronous rectification
The primary side of switching power circuit can produce very big electric current reverse surge.Acquisition module 10 in the control circuit of the present embodiment
It is connected with the primary side of the switching power circuit of circuit of synchronous rectification, when the primary side switch of the switching power circuit of circuit of synchronous rectification
Electric current reverse surge, when there is reverse surge current, switch of the acquisition module 10 from circuit of synchronous rectification occur for pipe rectification unit
The primary side of power circuit obtains the voltage signal that reverse surge current is produced, and can also be referred to as reverse voltage signal.Keep mould
Block 11 is connected with acquisition module 10, when the voltage signal that acquisition module 10 is obtained is more than default first voltage threshold value, pre-
If first time period in, persistently export the first control signal.Control module 12 is with keeping module 11 to be connected, according to holding module
First control signal of 11 outputs, turns off the switching tube of the secondary of the switching power circuit of circuit of synchronous rectification, to occur electricity
Prevent electric current reverse when flowing reverse surge, it is ensured that the switching tube in the switching power circuit of circuit of synchronous rectification avoids excessively stream from damaging
It is bad.
The control circuit of the present embodiment, when electric current reverse surge occurs for the primary side of the switching power circuit of circuit of synchronous rectification
When, by obtaining the voltage signal of reverse surge current generation and being detected and controlled, to turn off opening for circuit of synchronous rectification
The switching tube of the secondary of powered-down source circuit, the electric current that restrained effectively in the switching power circuit of circuit of synchronous rectification is reversely unrestrained
Gush, it is ensured that the safety of the switching tube in the switching power circuit of circuit of synchronous rectification.
Fig. 3 is the structural representation of the control circuit of the offer of the present embodiment two.As shown in figure 3, the control of the present embodiment
Circuit is on the basis of above-described embodiment one, in addition to a detection module 13.
Detection module 13 is connected with the secondary of the switching power circuit of circuit of synchronous rectification, for when circuit of synchronous rectification
When the output voltage of the secondary of switching power circuit is more than default second voltage threshold value, the second control signal is exported.Detect mould
Block 13 is also connected with control module 12.The second control signal that control module 12 can be exported according to detection module 13, control is led
The secondary-side switch pipe of the switching power circuit of logical circuit of synchronous rectification.
Due to when occurring reverse current surge, using the scheme of above-described embodiment one, rapidly switching off circuit of synchronous rectification
Switching power circuit secondary switching tube, so as to ensure the safety of switching tube.But sometimes, rapidly switch off synchronous whole
After the switching tube of the secondary of the switching power circuit of current circuit, because secondary output end reverse current does not discharge in time, make
Output voltage into secondary output voltage terminal is too high, and very big potential safety hazard is caused to system.The present embodiment is by setting one
Detection module 13, the detection module 13 is connected with the output end of the secondary of the switching power circuit of circuit of synchronous rectification, and detection is same
During the output voltage overvoltage output for the output voltage terminal for walking the secondary of the switching power circuit of rectification circuit, i.e. the output of secondary is electric
When pressure is more than default second voltage threshold value, the second control signal is exported, to turn on the switching power circuit of circuit of synchronous rectification
Secondary-side switch pipe driving, discharge circuit of synchronous rectification switching power circuit secondary output end reverse current.
The control circuit of the present embodiment, during can preventing or suppressing reverse current surge, the synchronous rectification electricity caused
The output voltage of the output voltage terminal of the secondary of the switching power circuit on road is too high, to the switching power circuit of circuit of synchronous rectification
Middle element causes to damage；The security in the switching power circuit of circuit of synchronous rectification can effectively be protected.
In above-mentioned two embodiment, the switch of the secondary of the switching power circuit of shut-off or conducting circuit of synchronous rectification
Pipe, can specifically be driven by the switching tube of the secondary for the switching power circuit for turning off or turning on circuit of synchronous rectification, with reality
Now turn off or turn on the switching tube of the secondary of the switching power circuit of circuit of synchronous rectification.Circuit of synchronous rectification can be opened
The switching tube of the secondary of powered-down source circuit is flexibly controlled.
Fig. 4 is the structural representation for the supply unit that the embodiment of the present invention three is provided.As shown in figure 4, the electricity of the present embodiment
Source device includes the switching power circuit 20 and control circuit 21 of circuit of synchronous rectification.
Circuit 21 is wherein controlled, can specifically be included：Acquisition module 10, holding module 11 and control module 12.Obtain mould
Block 10 is connected with the switching power circuit 20 of circuit of synchronous rectification, the original for the switching power circuit 20 when circuit of synchronous rectification
While when there is reverse surge current, obtaining the voltage signal that reverse surge current is produced.Module 11 is kept to connect with acquisition module 10
Connect, for when voltage signal is more than default first voltage threshold value, the first control persistently to be exported in default first time period
Signal processed.Control module 12 is connected with the switching power circuit 20 of circuit of synchronous rectification, for what is exported according to holding module 11
The secondary-side switch pipe of the switching power circuit 20 of first control signal control shut-off circuit of synchronous rectification.
The supply unit of the present embodiment, when occurring electric current reverse surge, by the voltage signal of acquisition and is detected,
With the switching tube of the secondary of the switching power circuit that turns off circuit of synchronous rectification, electric current reverse surge restrained effectively, it is ensured that
The safety of switching tube in the switching power circuit of circuit of synchronous rectification.Meanwhile, the operating efficiency of power supply is not only increased, also
Improve the reliability of power supply.
As shown in figure 4, also including detection module 13 in control circuit 21 in the supply unit of the present embodiment.Detection module
13 are connected with the switching power circuit 20 and control module 12 of circuit of synchronous rectification respectively, for when the switch of circuit of synchronous rectification
When the output voltage of the secondary of power circuit is more than default second voltage threshold value, the second control signal is exported, for control mould
Block 12 controls to turn on the secondary-side switch pipe of the switching power circuit of circuit of synchronous rectification according to the second control signal.
The supply unit of the present embodiment, during can preventing or suppressing reverse current surge, the synchronous rectification electricity caused
The overtension of the output end of the secondary of the switching power circuit on road, makes to element in the switching power circuit of circuit of synchronous rectification
Into damage；So as to effectively protect the security of the switching power circuit of circuit of synchronous rectification.
Simultaneously as prior art is that counnter attack diode or metal-oxide-semiconductor, meeting are set in rectification circuit Switching Power Supply major loop
One very big constant power loss is introduced in major loop；And the embodiment of the present invention and counnter attack two pole need not be set in major loop
Pipe or metal-oxide-semiconductor, but be controlled by an additional control circuit, fixed power can't be introduced in major loop and damaged
Consumption, and control the power attenuation of circuit to follow the constant power loss introduced in major loop to compare, it is very small；Therefore, use
The embodiment of the present invention, can be effectively saved power attenuation, improve the operating efficiency of power supply.
Control circuit 21 in the supply unit of the present embodiment specifically can be using the related of above-described embodiment one to two
Circuit is controlled, the record of above-described embodiment one to two is refer in detail, be will not be repeated here.
Fig. 5 implements the circuit diagram of four supply units provided for the present invention.As shown in figure 5, the supply unit is using such as
Control circuit in Fig. 5 shown in dotted line frame carrys out the switching power circuit of the circuit of synchronous rectification shown in control figure 1.
As shown in figure 5, on the basis of above-mentioned Fig. 2, Fig. 3 or embodiment illustrated in fig. 4, the control circuit of correspondence embodiment
In acquisition module include sample resistance R_SENSE and signal amplifier U1.
Wherein sample resistance R_SENSE is arranged in the primary side of the switching power circuit of circuit of synchronous rectification, to detect
Whether the primary side of the switching power circuit of circuit of synchronous rectification has zero passage reverse current i.Because reverse current i signal is more micro-
It is weak, the initial voltage signal that reverse current i is produced is obtained from sample resistance R_SENSE two ends using signal amplifier U1, and it is right
Voltage signal is amplified processing, obtains voltage signal.The sample resistance R_SENSE of the present embodiment can for conventional, electric-resistance,
Can be the DC impedance of line impedance, common mode or differential mode inductance, prime counnter attack or delay startup metal-oxide-semiconductor conducting resistance.Need
It is bright, use by " current sampling resistor " to detect reverse current in the present embodiment, similarly can also be using detection
The mode of input voltage is detected.
As shown in figure 5, the holding module of correspondence embodiment includes two the first divider resistance R1 concatenated and the second partial pressure
Resistance R2, comparator U2 and the first control unit.
Wherein the first divider resistance R1 one end is connected with amplifier U1 inputs, the second divider resistance R2 of other end series connection
After be grounded, while the other end is also connected with comparator U2 one of input.The voltage signal of amplifier U1 inputs is through the
Obtain the voltage signal after partial pressure after one divider resistance R1 partial pressures, and the voltage signal CMPin after the partial pressure is exported to comparing
Device U2 input.Comparator U2 is to the voltage signal CMPin after the partial pressure of reception and default first voltage threshold value Vref1
It is compared, when the voltage signal CMPin after partial pressure is more than first voltage threshold value Vref1, exports the first control signal
CMPout.Here the first divider resistance R1 and the second divider resistance R2 are designed, putting for flexible design amplifier U1 is can aid in
Vast scale and first voltage threshold value Vref1.
As shown in figure 5, being additionally provided with a reset pin i.e. Reset pins on comparator U2, the Reset pins are first
Level (is such as set to high level) in example of the present invention, and comparator U2 can play a part of " keeping ", and now comparator U2's is defeated
Go out the first control signal CMPout for remaining and being exported when being triggered.Now it is considered that comparator U2 is in input relatively and touched
Send out maintenance state.When comparator U2 Reset pins are second electrical level (such as being low level in this bright embodiment), comparator
U2 exports " being reset ", and recovery currently compares output state, i.e., according to comparative result output signal.Now it is considered that comparator
U2 is in the state for inputting and comparing output.
Specifically, the level of Reset pins is controlled by the first control unit.As shown in figure 5, the first control unit includes
Electric capacity C2, the first power supply VCC1 and the first pull-up resistor R3, current-limiting resistance R8, first resistor R9 and second resistance R10, and
First switch pipe Q9 and second switch pipe Q10.In embodiments of the present invention, control the switching tube in circuit all with triode come real
It is existing, (such as metal-oxide-semiconductor) switching tube can also be realized by other means in practical application, these realize that technology is those skilled in the art
Known technology, will not be repeated here.Referring to Fig. 5, electric capacity C2 one end is connected with Reset pins, other end ground connection.Its electric capacity
C2 one end after first resistor R9 and current-limiting resistance R8 series connection with the first power supply VCC1 also by with being connected.First power supply VCC1 is also
It is connected by the first pull-up resistor R3 with second switch pipe Q10.When comparator U2 exports the first control signal CMPout, conducting
Second switch pipe Q10, so as to cause first switch pipe Q9 to turn on.Turn on after first switch pipe Q9, electric capacity C2 passes through by first
Resistance R9, first switch pipe Q9 and electric capacity C2 compositions loop electric discharge, cause the voltage drop of Reset pins being connected with electric capacity C2
It is low, i.e., Reset pins are reduced to low level by high level.Can take from when detectable voltage signals be more than first voltage threshold value when,
Comparator U2 starts the first control signal CMPout of output until Reset pins are reduced to the low level time for first time period.
By default first resistor R9 resistance (with electric capacity C2 discharge loop, it is relevant with electric capacity C2 discharge time), can be with
The length of default first time period.In the first time period, Reset pins are high level, and comparator U2 is in " input is compared simultaneously
Triggering is maintained " state, the effect with " maintenance ".Now comparator U2 is persistently exported according to voltage signal and first voltage threshold
The first control signal CMPout that value Vref1 compares and exported, until Reset pins are reduced to low level.The first time period
Length should be more than or equal to the working time that primary side metal-oxide-semiconductor driving pulse is modulated.It thereby may be ensured that circuit of synchronous rectification
The potential safety hazard of Switching Power Supply.Reset pins are reduced to low level, comparator U2 outputs " being reset ", now at comparator U2
In the state of " input and compare output ", i.e. the voltage signal to input and first voltage threshold value Vref1 is compared, and according to
Comparative result output signal.
As shown in figure 5, control module includes optocoupler U3 and the second control unit.One end of photodiode in optocoupler U3
It is connected with the first power supply VCC1, the other end is connected with second switch pipe Q10.When comparator U2 exports the first control signal
CMPout, during conducting second switch pipe Q10, drives photodiode in optocoupler U3 to send photoelectron, so as to turn in optocoupler U3
Triode receives photoelectron, so as to turn on the work of the second control unit.
As shown in figure 5, the second control unit includes second source VCC2,3rd resistor R4, the 4th resistance R7 and ground connection electricity
Hinder R5, the 3rd switching tube Q11, the 4th switching tube Q12 and the first triode Q13.As shown in figure 5, the first triode Q13 here
Using the metal-oxide-semiconductor of positive-negative-positive.First triode Q13 emitter stage is connected with second source VCC2, and second source VCC2 also passes through
Four resistance R7 are connected with the first triode Q13 base stage, to play a part of controlling the first triode Q13 turn-on thresholds.First
Triode Q13 colelctor electrode is grounded by grounding resistance R5, and the first triode Q13 base stage passes through 3rd resistor R4 and optocoupler U3
In triode colelctor electrode connection, the grounded emitter of optocoupler U3 triode.3rd switching tube Q11 and the 4th switching tube
Colelctor electrodes of the Q12 respectively with the first triode Q13 is connected and (can also connected respectively by resistance).When optocoupler U3 ON operations
When, the first triode Q13 conductings, now the level CNT at the first triode Q13 colelctor electrode is high level；So as to control the
Three switching tube Q11 and the 4th switching tube Q12 conductings.With reference to Fig. 5, in the work process of the power circuit of circuit of synchronous rectification.
The first drive signal DRVA and the second drive signal DRVB are the drivings of the first driving U4 and second U5 driving input respectively in Fig. 5
Signal.As shown in figure 5, after the 3rd switching tube Q11 and the 4th switching tube Q12 conductings, the first drive signal DRVA of short circuit and the
Two driving signal DRVB (i.e. by DRVA, DRVB down for 0), so as to turn off the synchronization of the driving U5 outputs of the first driving U4 and second
Rectification drive amplification signal, also just have turned off the switching tube Q5-Q8 of the secondary of the switching power circuit of circuit of synchronous rectification.
The control circuit and corresponding supply unit of the present embodiment, it is reverse by obtaining when occurring electric current reverse surge
The voltage signal of surge current generation is simultaneously detected, with the switching tube of the secondary of the switching power circuit to circuit of synchronous rectification
Turn off, restrained effectively electric current reverse surge, it is ensured that the peace of the switching tube in the Switching Power Supply of circuit of synchronous rectification
Entirely.Thus it is guaranteed that the reliability of voltage.Simultaneously as prior art is set in rectification circuit Switching Power Supply major loop
Counnter attack diode or metal-oxide-semiconductor, can introduce one very big constant power loss in major loop；And the embodiment of the present invention and need not
Counnter attack diode or metal-oxide-semiconductor are set in major loop, but are controlled by an additional control circuit, can't led back
Pass enters fixed power attenuation, and controls the power attenuation of circuit to follow the constant power loss introduced in major loop to compare, and is
It is very small；Therefore, using the embodiment of the present invention, power attenuation can be effectively saved, the operating efficiency of power supply is improved.
As shown in figure 5, the control circuit of the present embodiment can also include detection module, the detection module includes at least one
Voltage-regulator diode.As shown in figure 5, the first voltage-regulator diode D1 and the second voltage-regulator diode D2 and second to include two concatenations
Exemplified by pull-up resistor R6.The output voltage terminal of the secondary of the switching power circuit of first voltage-regulator diode D1 and circuit of synchronous rectification
It is connected, the second voltage-regulator diode D2 is connected by the second pull-up resistor R6 with the first triode Q13 base stage.
As shown in figure 5, when the output voltage of the secondary of the switching power circuit of circuit of synchronous rectification is more than by the first voltage stabilizing
(the second voltage threshold value is equal to the first voltage stabilizing during the second voltage threshold value that diode D1 and the second voltage-regulator diode D2 are determined jointly
Diode D1 and the second voltage-regulator diode D2 voltage of voltage regulation sum), the first voltage-regulator diode D1 of conducting and the second voltage-regulator diode
D2, can pull up the base voltage that the second pull-up resistor R6 improves the first triode Q13, so as to disconnect the first triode Q13.This
When, accordingly, the level CNT at the first triode Q13 colelctor electrode is low level.Accordingly, it is disconnected the 3rd switching tube Q11
With the 4th switching tube Q12 so that recover to first driving U4 and second driving U5 input the first drive signal DRVA and second drive
Dynamic signal DRVB, the first drive signal DRVA and the second drive signal DRVB control conducting first drives the driving U5 of U4 and second,
So as to turn on the secondary-side switch pipe Q5-Q8 of the Switching Power Supply of circuit of synchronous rectification, the switch power supply of circuit of synchronous rectification is discharged
The voltage of the output end of the secondary on road.Therefore CNT level signals are the second control signal, can be according to the height of CNT level signals
It is low, the secondary-side switch pipe of the switching power circuit of control shut-off or conducting circuit of synchronous rectification.
As shown in figure 5, reverse current is detected using sample resistance R_SENSE, because the signal of reverse current is fainter,
Voltage signal is obtained from sample resistance R_SENSE two ends using signal amplifier U1.Through the first divider resistance R1 and the second partial pressure
After resistance R2 partial pressures, the voltage signal CMPin inputted to comparator U2 input after partial pressure.Comparator U2 is by the electricity received
Pressure signal is compared with default first voltage threshold value Vref1.When voltage signal is more than first voltage threshold value Vref1, compare
Device U2 exports the first control signal CMPout, so as to turn on second switch pipe Q10.Second switch pipe Q10 conducting simultaneously, can be with
Open first switch pipe Q9 so that electric capacity C2 and first resistor R9 formation loop, electric capacity C2 starts electric discharge.Therefore so that with electricity
The Reset pins for holding the connected comparator U2 of C2 anodes are gradually reduced to low level by high level.
As shown in figure 5, simultaneously after comparator U2 exports the first control signal CMPout conducting second switch pipe Q10,
So as to drive optocoupler U3 to work, to turn on the first triode Q13.First triode Q13 conducting, can turn on the 3rd switching tube
Q11 and the 4th switching tube Q12, so as to turn off the of the switching tube of the secondary of switching power circuit respectively to circuit of synchronous rectification
The first drive signal DRVA and the second drive signal DRVB that one driving U4 and the second driving U5 are sent respectively.Wherein first driving
Signal DRVA and the second drive signal DRVB controls disconnect or closed the secondary of the switching power circuit of circuit of synchronous rectification
First driving U4 of switching tube and the second driving U5, so as to realize the switching power circuit for disconnecting or closing circuit of synchronous rectification
Secondary switching tube.Such as the first drive signal DRVA control disconnect or closure first drive U4 so that control disconnect or
Person closes the switching tube Q5 and Q8 of secondary.Second drive signal DRVB controls disconnect or closure second drives U5, so as to control
Disconnect or close the switching tube Q6 and Q7 of secondary.
The control circuit and corresponding supply unit of the present embodiment, can prevent during suppression reverse current surge, make
Into the overtension of the output end of the secondary of the switching power circuit of circuit of synchronous rectification, to the Switching Power Supply of circuit of synchronous rectification
Element causes to damage in circuit；Effectively protect the security of the switching power circuit of circuit of synchronous rectification.
Fig. 6 is a kind of signal sequence oscillogram of circuit shown in Fig. 5.With reference to shown in the circuit and Fig. 6 shown in Fig. 5
Timing diagram.The workflow of circuit shown in Fig. 5 is discussed in detail.
As shown in fig. 6, the t0 moment, in the switching power circuit primary side of circuit of synchronous rectification, when input reverse current i exceedes
The current flowing backwards of power inlet occur for certain threshold value, now comparator U2 judgements, at this moment comparator U2 outputs the first control letter
Number CMPout, and trigger as height, because the level of comparator U2 RESET pin is height, the first control signal CMPout output shapes
State is kept, and at this moment second switch pipe Q10 is turned on, and signal is delivered to secondary by the optocoupler U3 of high speed, turns on the first triode
Q13, accordingly the CNT level at the first triode Q13 colelctor electrode is height, so as to turn on the collection with the first triode Q13
Electrode connected the 3rd switching tube Q11 and the 4th switching tube Q12, so as to cut off to the first driving U4 and the second driving U5 inputs the
One drive signal DRVA and the second drive signal DRVB, wherein the first driving U4 controls the switching tube Q5 and Q8 of secondary；Second drives
Dynamic U5 controls the switching tube Q6 and Q7 of secondary.Therefore, accordingly, the switching tube Q5 of the first drive signal DRVA controls shut-off secondary
And Q8, the second drive signal DRVB control have turned off the switching tube Q6 and Q7 of secondary.So as to prevent opening for circuit of synchronous rectification
Anti- sink current continues to increase in powered-down source.While the t0 moment is height, first switch pipe Q9 meetings due to the first control signal CMPout
Conducting, makes voltage on RESET pin slowly decline.
State is continued until the t1 moment, as the output voltage DEC_ for the switching power circuit for detecting circuit of synchronous rectification
There is output overvoltage, the first voltage-regulator diode D1 and the second voltage-regulator diode D2 conductings in VOUT, so as to improve the first triode
The voltage of Q13 base stages.End the first triode Q13 by the second pull-up resistor R6, at the first triode Q13 colelctor electrode
CNT level is low, therefore is disconnected the 3rd switching tube Q11 and the 4th switching tube Q12, so as to recover to the first driving U4 and second
U5 is driven to input the first drive signal DRVA and the second drive signal DRVB, the first driving U4 and the second driving U5, control conducting
The switching tube Q5 and Q8 of secondary.The output voltage DEC_VOUT of the switching power circuit of circuit of synchronous rectification is clamped by primary side, is prevented
Only there is output overvoltage.
When output overvoltage returns to normal range (NR), t2 moment, the first voltage-regulator diode D1 and the second voltage-regulator diode D2 are cut
Only, because the first control signal CMPout output state is kept, the CNT level at the first triode Q13 colelctor electrode is still defeated
Go out for height, the 3rd switching tube Q11 and the 4th switching tube Q12 are switched on respectively, so as to cut off to the first driving U4 and the second driving
U5 inputs the first drive signal DRVA and the second drive signal DRVB, so as to control to have turned off the Switching Power Supply of circuit of synchronous rectification
Secondary switching tube Q5-Q8, it is therefore prevented that anti-sink current continues to increase in the Switching Power Supply of circuit of synchronous rectification.Meanwhile, during t2
Carve the first control signal CMPout and be output as height, first switch pipe Q9 can be turned on, voltage on RESET pin electric capacity is continued slow
Decline.
Until the t3 moment, the RESET level slowly declined is low, at this moment because input does not detect current flowing backwards shape
State, the first control signal CMPout is output as low, and it is low, shut-off the 3rd to make CNT level at the first triode Q13 colelctor electrode
Switching tube Q11 and the 4th switching tube Q12, so as to recover to input the first drive signal DRVA to the first driving U4 and the second driving U5
With the second drive signal DRVB, the switching power circuit of circuit of synchronous rectification recovers normal operating conditions.
Fig. 7 is the flow chart of the control method for the suppression reverse current surge that the embodiment of the present invention five is provided.The present embodiment
Executive agent for control circuit.As shown in fig. 7, the control method of the suppression reverse current surge of the present embodiment, specifically can be with
Comprise the following steps：
Step 100, when there is reverse surge current in the primary side of the switching power circuit of circuit of synchronous rectification, obtain reverse
The voltage signal that surge current is produced；
Step 101, when voltage signal be more than default first voltage threshold value when, in default first time period continue it is defeated
Go out one first control signal；
Step 102, according to the first control signal, the secondary-side switch of the switching power circuit of control shut-off circuit of synchronous rectification
Pipe.
Specifically, in the Switching Power Supply of circuit of synchronous rectification, when input power generation low-resistance is anti-drop, synchronous rectification
The primary side of the Switching Power Supply of circuit can produce very big electric current reverse surge.When the primary side of the Switching Power Supply of circuit of synchronous rectification is opened
When pass pipe rectification unit generation electric current is reverse, the voltage signal that reverse current is produced is obtained.When the voltage signal of acquisition is more than in advance
If first voltage threshold value when, in default first time period, persistently export the first control signal.Finally according to the first control
Signal, turns off the switching tube of the secondary of the Switching Power Supply of circuit of synchronous rectification, with when occurring electric current reverse surge, it is ensured that synchronous
Switching tube in the switching power circuit of rectification circuit avoids being damaged.
The control method of the suppression reverse current surge of the present embodiment, it is anti-by obtaining when occurring electric current reverse surge
The voltage signal that is produced to surge current is simultaneously detected, is entered with the switching tube of the secondary of the Switching Power Supply to circuit of synchronous rectification
Row disconnects, and restrained effectively electric current reverse surge, it is ensured that the safety of switching tube in the Switching Power Supply of circuit of synchronous rectification.Cause
This, it is ensured that the reliability of power supply, simultaneously, using the technical scheme of the present embodiment, additionally it is possible to ensure the operating efficiency of power supply.
The flow chart of the control method for the suppression reverse current surge that Fig. 8 embodiment of the present invention six is provided.In above-mentioned Fig. 7 institutes
On the basis of showing embodiment, as shown in figure 8, the control method of the suppression reverse current surge of the present embodiment, in above-mentioned steps 102
Afterwards, it can also specifically comprise the following steps：
Step 103, when circuit of synchronous rectification switching power circuit secondary output voltage be more than default second electricity
When pressing threshold value, the second control signal is exported；
Step 104, according to the second control signal, the secondary-side switch of the switching power circuit of control conducting circuit of synchronous rectification
Pipe.
Specifically, due to when being sent to current surge, using the scheme of above-described embodiment five, rapidly switch off synchronous whole
The switching tube of the secondary of the switching power circuit of current circuit, so as to ensure the safety of switching tube.But sometimes, rapidly switch off
After the switching tube of the secondary of the switching power circuit of circuit of synchronous rectification, because the voltage of secondary output end is not released in time
Put, cause the overtension of secondary output end, very big potential safety hazard is caused to power supply.The present embodiment is by detecting synchronous rectification
The voltage of the output end of the secondary of the switching power circuit of circuit, when the pair for the switching power circuit for detecting circuit of synchronous rectification
During the electric voltage over press output of the output end on side, i.e., when the output voltage of secondary is more than default second voltage threshold value, output second
Control signal, with the secondary-side switch pipe for the switching power circuit for turning on circuit of synchronous rectification, discharges the switch of circuit of synchronous rectification
The voltage of the output end of the secondary of power circuit.
The present embodiment suppression reverse current surge control method, can prevent suppress reverse current surge during,
The overtension of the output end of the secondary of the switching power circuit of circuit of synchronous rectification is caused, to the switch electricity of circuit of synchronous rectification
Element causes to damage in source circuit；The security of the switching power circuit of circuit of synchronous rectification can effectively be protected.Therefore, protect
The reliability, simultaneously of power supply is demonstrate,proved, using the technical scheme of the present embodiment, additionally it is possible to ensure the operating efficiency of power supply.
The implementation process and above-mentioned Fig. 1-Fig. 6 of the control method of Fig. 7 and the suppression reverse current surge of embodiment illustrated in fig. 8
The realization mechanism that the control circuit or control circuit of corresponding embodiment are in corresponding power device is identical, also can refer in detail
The associated description of above-mentioned control circuit embodiments, will not be repeated here.
One of ordinary skill in the art will appreciate that：Realizing all or part of step of above method embodiment can pass through
Programmed instruction related hardware is completed, and foregoing program can be stored in a computer read/write memory medium, the program
Upon execution, the step of including above method embodiment is performed；And foregoing storage medium includes：ROM, RAM, magnetic disc or light
Disk etc. is various can be with the medium of store program codes.
Finally it should be noted that：The above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations；Although
The present invention is described in detail with reference to the foregoing embodiments, it will be understood by those within the art that：It still may be used
To be modified to the technical scheme described in foregoing embodiments, or equivalent substitution is carried out to which part technical characteristic；
And these modification or replace, do not make appropriate technical solution essence depart from various embodiments of the present invention technical scheme spirit and
Scope.
Claims (8)
1. one kind control circuit, it is characterised in that including：
Acquisition module, is joined directly together with the power input of the primary side of the switching power circuit of circuit of synchronous rectification, is arranged on institute
State the switch power supply of the power input and the circuit of synchronous rectification of the primary side of the switching power circuit of circuit of synchronous rectification
Between the input filter capacitor of the primary side on road, the power input for the primary side of the switching power circuit when circuit of synchronous rectification
When there is reverse surge current, the voltage signal that the reverse surge current is produced is obtained；
Module is kept, for when the voltage signal is more than default first voltage threshold value, in default first time period
Persistently export the first control signal；
Control module, for being controlled to turn off the switching power circuit of the circuit of synchronous rectification according to first control signal
All secondary-side switch pipes；
Wherein, the acquisition module includes current sampling resistor and signal amplifier；
In the sample resistance, the primary side for being arranged on the switching power circuit of the circuit of synchronous rectification；
The signal amplifier, for obtaining the initial voltage letter that the reverse surge current is produced from the sample resistance two ends
Number, and the initial voltage signal is amplified processing, obtain the voltage signal；
The holding module includes comparator, the first control unit：
The comparator, for being compared to the voltage signal and the default first voltage threshold value, when the voltage
When signal is more than the first voltage threshold value, first control signal is exported；
Reset pin is provided with the comparator, when the reset pin is the first level, the comparator is in input
Relatively and maintenance state is triggered, the comparator persistently exports first control signal；When the reset pin is the second electricity
Usually, the comparator is reset, and recovers to input and compare the state of output；
First control unit, for when the voltage signal is more than the first voltage threshold value, the comparator to be exported
During first control signal, the voltage reduction of the reset pin is controlled, until causing by the first time period described
Reset pin is low level；
First control unit includes：Electric capacity, one end of the electric capacity is connected with the reset pin, other end ground connection；
One end of the electric capacity is also connected by resistance with the first power supply, for not exporting first control when the comparator
During signal, it is high level to keep described electric capacity one end, to cause the reset pin as high level；When the comparator exports institute
When stating the first control signal, first control signal controls the electric capacity electric discharge, to reduce the voltage of the reset pin, directly
The reset pin is caused to be reduced to low level to by the first time period；
The control module includes optocoupler and the second control unit；
The optocoupler, for according to first control signal, turning on second control unit；
Second control unit, all pairs of the switching power circuit of control shut-off circuit of synchronous rectification during for turning on
Side switching tube.
2. control circuit according to claim 1, it is characterised in that also including detection module, for when the synchronization it is whole
When the output voltage of the secondary of the switching power circuit of current circuit is more than default second voltage threshold value, the control letter of output second
Number；
The control module, is additionally operable to be controlled to turn on the Switching Power Supply of the circuit of synchronous rectification according to second control signal
The secondary-side switch pipe of circuit.
3. control circuit according to claim 2, it is characterised in that the control module, is additionally operable to according to described second
The driving of the secondary-side switch pipe of the switching power circuit of the control signal control conducting circuit of synchronous rectification, it is described same to turn on
Walk the secondary-side switch pipe of the switching power circuit of rectification circuit.
4. control circuit according to claim 1, it is characterised in that the holding module also includes at least two concatenations
Divider resistance；One end of the divider resistance of at least two concatenation is connected with the voltage signal, other end ground connection；It is described extremely
The divider resistance of few two concatenations is used to carry out partial pressure to the voltage signal, and branch pressure voltage signal is exported to the comparator；
The comparator, specifically for being compared to the branch pressure voltage signal and the default first voltage threshold value, when
When the branch pressure voltage signal is more than the first voltage threshold value, first control signal is exported.
5. control circuit according to claim 2, it is characterised in that second control unit includes second source, the
One triode and grounding resistance；
The emitter stage of first triode is connected with the second source, and the colelctor electrode of first triode is connect by described
Ground resistance eutral grounding；
The optocoupler is by turning on first triode, the institute of the switching power circuit of the control shut-off circuit of synchronous rectification
There is secondary-side switch pipe.
6. control circuit according to claim 5, it is characterised in that the detection module includes at least one pole of voltage stabilizing two
Pipe, at least one described voltage-regulator diode one end and the output voltage of the secondary of the switching power circuit of the circuit of synchronous rectification
End is connected, and the other end is connected with the base stage of first triode；
At least one described voltage-regulator diode, the output electricity for the secondary of the switching power circuit in the circuit of synchronous rectification
When pressure is more than the default second voltage threshold value at least one described voltage-regulator diode, first triode is turned off, and
The secondary-side switch pipe of the switching power circuit of the control conducting circuit of synchronous rectification.
7. control circuit according to claim 1, it is characterised in that the control module, specifically for according to described
The driving of the secondary-side switch pipe of the switching power circuit of the one control signal control shut-off circuit of synchronous rectification, it is described to turn off
All secondary-side switch pipes of the switching power circuit of circuit of synchronous rectification.
8. a kind of supply unit, including circuit of synchronous rectification switching power circuit and as above claim 1-7 is any described
Control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410614004.9A CN104348365B (en) | 2010-06-28 | 2010-06-28 | Control circuit and method, supply unit |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010102128374A CN101895207A (en) | 2010-06-28 | 2010-06-28 | Control circuit and method and power supply device |
| CN201410614004.9A CN104348365B (en) | 2010-06-28 | 2010-06-28 | Control circuit and method, supply unit |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010102128374A Division CN101895207A (en) | 2010-06-28 | 2010-06-28 | Control circuit and method and power supply device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104348365A CN104348365A (en) | 2015-02-11 |
| CN104348365B true CN104348365B (en) | 2017-10-17 |
Family
ID=52503361
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410614004.9A Active CN104348365B (en) | 2010-06-28 | 2010-06-28 | Control circuit and method, supply unit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104348365B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170117813A1 (en) * | 2015-10-21 | 2017-04-27 | Quanta Computer Inc. | Method and system for testing a power supply unit |
| CN110249273B (en) * | 2017-02-17 | 2021-02-12 | 华为技术有限公司 | Control circuit and circuit control method |
| CN109347314B (en) * | 2018-10-29 | 2020-12-18 | 陕西航空电气有限责任公司 | High-voltage AC/DC residual current discharge circuit with protection function |
| CN109742954A (en) * | 2019-01-07 | 2019-05-10 | 广州金升阳科技有限公司 | A kind of DC/DC converter |
| CN110768215B (en) * | 2019-10-22 | 2021-11-12 | 广州金升阳科技有限公司 | Output overvoltage protection control circuit of switching power supply and control method thereof |
-
2010
- 2010-06-28 CN CN201410614004.9A patent/CN104348365B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN104348365A (en) | 2015-02-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101895207A (en) | Control circuit and method and power supply device | |
| CN104348365B (en) | Control circuit and method, supply unit | |
| WO2019129027A1 (en) | Boost power conversion circuit | |
| CN104079276B (en) | High-efficiency intelligent high-side electronic load switch with wide voltage adaptability | |
| WO2018129831A1 (en) | Smart short circuit protection switch circuit for modified wave inverter | |
| CN102777666B (en) | Electromagnetic valve control circuit and electromagnetic valve closing self-checking method thereof | |
| CN108008322A (en) | The detection method and circuit of multiple power supplies | |
| CN109981057A (en) | The modulator approach of GaN power amplifier drain power modulation chip | |
| CN106685196B (en) | IGBT parallel drive and Drive Protecting Circuit in a kind of high-power high voltage frequency converter | |
| CN106788367A (en) | A kind of IGBT drive circuit | |
| CN104332943A (en) | DC protection circuit | |
| CN206353445U (en) | A kind of power supply circuit of solid state hard disc | |
| CN106160071B (en) | Short-circuit protection circuit | |
| CN203574367U (en) | Reverse connection protective circuit of power supply | |
| CN110098605A (en) | One kind being based on PMOS tube low-voltage DC supply drive power supply reverse-connection preventing circuit | |
| CN209516620U (en) | A kind of output protection circuit of DC power supply | |
| CN103826363A (en) | Hot-plugging protection circuit for LED illuminating apparatus | |
| CN205811524U (en) | Short-circuit protection circuit | |
| CN206340954U (en) | A kind of LED drive power and its output end short-circuit protection circuit | |
| CN204886152U (en) | Power device pursues pulse protection circuit | |
| CN212572067U (en) | Novel output short circuit double protection circuit of inverter | |
| CN203384023U (en) | Compressor overload protection system | |
| CN204497969U (en) | A kind of safe food processor | |
| CN206353183U (en) | A kind of open-loop voltage detecting system | |
| CN105391273A (en) | Power controller of counter device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |