CN108336917A - A kind of switching power circuit - Google Patents
A kind of switching power circuit Download PDFInfo
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- CN108336917A CN108336917A CN201810333152.1A CN201810333152A CN108336917A CN 108336917 A CN108336917 A CN 108336917A CN 201810333152 A CN201810333152 A CN 201810333152A CN 108336917 A CN108336917 A CN 108336917A
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Classifications
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- 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
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
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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
- 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
- H02H7/1255—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 responsive to internal faults, e.g. by monitoring ripple in output voltage
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a kind of switching power circuits, including sequentially connected protection circuit, input filter circuit, current rectifying and wave filtering circuit, master power switch pipe circuit, isolated buck circuit and output rectifier and filter；The output end of output rectifier and filter forms voltage negative feedback loop through sequentially connected isolation negative-feedback circuit, control circuit, master power switch pipe circuit and isolated buck circuit.The AC power of power grid can be become to stablize the direct current of output for the power supply of the electrical appliances such as electric pump by the present invention；And the output end of output rectifier and filter forms voltage negative feedback loop through sequentially connected isolation negative-feedback circuit, control circuit, master power switch pipe circuit and isolated buck circuit; the high-frequency interferencing signal in input power can not only be filtered out; the voltage of output direct current can also be stablized by voltage negative feedback loop; used control circuit has short-circuit protection, overcurrent protection and power-down protection, ensure that the safety of power supply.
Description
Technical field
The invention belongs to technical field of circuit control, and in particular to a kind of switching power circuit.
Background technology
Electric pump is with the pump of all kinds of liquid mediums of all kinds of conveyings of electric drive, such as water pump, oil pump, concrete pump, warp
It is often used in daily work and life.But the most power supply module of current electric pump is single, can only use alternating current
Or powered by direct current, it is also not convenient enough to use, and influences working efficiency.
It is existing to exchange the following defect of switching power circuit generally existing for turning direct current：When in input power doped with interference
When electromagnetic wave, power circuit anti-interference is poor, the direct current that cannot steadily export, and generates high pressure or short circuit when having to be struck by lightning
When generation electric current is excessive, it is easy to burn out motor, generates security risk.
Invention content
It is an object of the invention to be directed to the above problem in the prior art, a kind of switching power circuit is provided, can be incited somebody to action
The direct current that the AC power of power grid becomes to stablize output is powered for electrical appliances such as electric pumps, and strong interference immunity uses peace
Entirely.
For achieving the above object, present invention employs following technical solutions：
A kind of switching power circuit, including sequentially connected protection circuit, input filter circuit, current rectifying and wave filtering circuit, master
Power switch tube circuit, isolated buck circuit and output rectifier and filter；The output end of output rectifier and filter is through successively
Isolation negative-feedback circuit, control circuit, master power switch pipe circuit and the isolated buck circuit of connection form negative voltage feedback and return
Road；Wherein：
The protection circuit is connect with AC power, for inhibiting the current or voltage of input power excessive, protects circuit
It is not burned；
The input filter circuit, for rectifying and wave-filtering electricity will to be transferred to after the electromagnetic interference signal filtering in AC power
Road；
The current rectifying and wave filtering circuit, for being transferred to main work(after ac signal is converted to more stable DC signal
Rate switching tube circuit；
The master power switch pipe circuit, for according to the pulse-width modulation PWM signal transmitted from control circuit, controlling main work(
The on or off of rate switching tube carries out negative feedback control by voltage negative feedback loop, exports and stablize to isolated buck circuit
Ac signal；
For the alternating current of master power switch pipe circuit output to be depressured, and height is isolated in the isolated buck circuit
It is transferred to output rectifier and filter and control circuit respectively after frequency clutter；
The output rectifier and filter, the alternating current for exporting isolated buck circuit export after carrying out rectifying and wave-filtering
Obtain stable direct current；
The isolation negative-feedback circuit passes through voltage negative for receiving the direct current exported by output rectifier and filter
Backfeed loop carries out negative feedback control, and the DC voltage of output is made to keep stablizing；
The control circuit, the signal progress negative feedback control for receiving isolation negative-feedback circuit output, and to main work(
Rate switching tube circuit transmission pulse-width modulation PWM signal, makes master power switch pipe circuit turn-on or shutdown.
Above-mentioned protection circuit includes self- recoverage insurance F1, varistor MOV1 and NTC thermistor NCT1；The self- recoverage
Insurance F1, varistor MOV1, NTC thermistor NCT1, AC power are sequentially connected in series.
Above-mentioned input filter circuit includes the X filter capacitors C1 for collectively constituting π type filter circuits, the filter of mutual induction filter T1, Y
Wave capacitance C2 and Y filter capacitor C3；The both ends of X filter capacitors C1 are separately connected two output ends of protection circuit；Inductive filter
Two input terminals of two output ends connection current rectifying and wave filtering circuit of device T1.
Above-mentioned current rectifying and wave filtering circuit includes rectifier bridge D1 and filter capacitor C4；The input terminal connection input of the rectifier bridge D1
Filter circuit, positive and negative the two poles of the earth of output end are separately connected the anode and cathode of filter capacitor C4；The anode of filter capacitor C4 is through coupling
Capacitance C10 ground connection is closed, the cathode of filter capacitor C4 is separately connected master power switch pipe circuit and ground connection.
Above-mentioned master power switch pipe circuit includes that metal-oxide-semiconductor Q1, pull-up resistor R1, metal-oxide-semiconductor driving circuit and RCT absorb electricity
Road；The grid of the metal-oxide-semiconductor connects control circuit through metal-oxide-semiconductor driving circuit, and metal-oxide-semiconductor driving circuit is used for basis from control circuit
The pulse-width modulation PWM signal transmitted makes metal-oxide-semiconductor Q1 on or off；The source electrode of metal-oxide-semiconductor Q1 connects current rectifying and wave filtering circuit；Metal-oxide-semiconductor
The drain electrode of Q1 connects isolated buck circuit through RCT absorbing circuits, and RCT absorbing circuits are for absorbing peak voltage and electric current；Pull-up
The both ends of resistance R1 are separately connected the grid and source electrode of metal-oxide-semiconductor Q1.
Above-mentioned metal-oxide-semiconductor driving circuit include triode Q2, triode Q3, diode D2, resistance R2, resistance R3, resistance R4,
Resistance R5；The diode D2 connect the grid of metal-oxide-semiconductor Q1 with the anode common end after resistance R2 parallel connections through resistance R3, and cathode is public
End is connect with the poles E of the poles E of triode Q2 and triode Q3 respectively altogether；The B of triode Q2 and triode Q3 are extremely jointly through resistance
R5 connection control circuits；The poles C of triode Q2 are grounded；Output of the poles C of triode Q3 through resistance R4 connection isolated buck circuits
End.
The RCT absorbing circuits include diode D6, resistance R17 and capacitance C9；Sun after resistance R17 is in parallel with capacitance C9
An input terminal of the pole common end through positive diode D6 connection isolated buck circuits, cathode common end is separately connected metal-oxide-semiconductor
The drain electrode of Q1 and another input terminal for connecting isolated buck circuit.
Above-mentioned isolated buck circuit includes high frequency switch transformer T2；Master power switch pipe circuit and current rectifying and wave filtering circuit
Output end connects the primary side of high frequency switch transformer T2；The secondary side connection output rectification filter electricity of the first of high frequency switch transformer T2
Road；The Same Name of Ends ground connection on the secondary side of the second of high frequency switch transformer T2, activated resistance again is distinguished at different name end after diode D3
The input terminal of R18 connection filter rectifiers, and access the feeder ear of control circuit.
Above-mentioned output rectifier and filter includes diode D4, diode D5, resistance R6, resistance R7, capacitance C5, capacitance
C6, electrolytic capacitor C7, electrolytic capacitor C8 and inductance L1；The Same Name of Ends on the secondary sides the high frequency switch transformer T2 first and different name end
The DC output end anode of output rectifier and filter is commonly connected to through positive diode D4 and diode D5 respectively；Electricity
Both ends are in parallel with diode D4 after resistance R6 connects with capacitance C5；Both ends are in parallel with diode D5 after resistance R7 connects with capacitance C6；
The Same Name of Ends on the secondary sides high frequency switch transformer T2 first is grounded through inductance L1；Sun after electrolytic capacitor C7 is in parallel with electrolytic capacitor C8
Pole common end connects the DC output end anode of output rectifier and filter, cathode common end grounding.
Above-mentioned isolation negative-feedback circuit includes photo-coupler U1 and voltage negative feedback circuit；The voltage negative feedback circuit packet
Include voltage stabilizing triode U2, potentiometer R8, resistance R9, resistance R10, resistance R11, resistance R12, resistance R13 and capacitance C9；It is described steady
Press the poles the C ground connection of triode U2；The resistance R12 that the poles E of voltage stabilizing triode U2 are concatenated connects output rectification filter with resistance R10
The DC output end anode of circuit；The poles B of voltage stabilizing triode U2 are grounded through potentiometer R8 and resistance R9 successively, and through resistance
The DC output end anode of R11 connection output rectifier and filters；Both ends after resistance R13 connects with capacitance C7 are separately connected
The poles E and the poles B of voltage stabilizing triode U2；Node between the anode input terminal access resistance R10 and resistance R12 of photo-coupler U1,
Cathode input terminal connects the poles E of voltage stabilizing triode U2；The output end of photo-coupler U1 connects control circuit.
Above-mentioned control circuit include short-circuit protection circuit, current foldback circuit, power-down protection circuit, current sampling circuit,
Switching Power Supply controls chip U3 and its peripheral circuit；The short-circuit protection circuit, current foldback circuit, power-down protection circuit are divided equally
Not with negative-feedback circuit and Switching Power Supply be isolated control chip U3 connections；Current rectifying and wave filtering circuit is accessed in one end of current sampling circuit
Between master power switch pipe circuit, other end connecting valve power supply control chip U3；Switching Power Supply controls the power supply of chip U3
The output end of end connection isolated buck circuit.
The current sampling circuit includes resistance R14, resistance R15 and resistance R16；One end of resistance R14 is grounded, the other end
Connect master power switch pipe circuit；Resistance R15 connects master power switch pipe circuit, the other end with one end after resistance R16 series connection
Connect control circuit.
Compared with the prior art, advantage of the invention is that：
The AC power of power grid can be become the direct current for stablizing output by a kind of switching power circuit provided by the invention
It is powered for electrical appliances such as electric pumps；And the output end of output rectifier and filter is through sequentially connected isolation negative-feedback electricity
Road, control circuit, master power switch pipe circuit and isolated buck circuit form voltage negative feedback loop, can not only filter out defeated
Enter the high-frequency interferencing signal in power supply, can also stablize the voltage of output direct current by voltage negative feedback loop, it is used
Control circuit has short-circuit protection, overcurrent protection and power-down protection, ensure that the safety of power supply.
The circuit for controlling motor of the present invention is applicable in various electric pumps, such as water pump, oil pump, concrete pump, can be used
Direct current or a variety of power supplies of exchange, export reliable and stable direct current, strong interference immunity ensure that the safety of power supply.
Description of the drawings
Fig. 1 is the circuit module block diagram of the present invention.
Fig. 2 is the circuit diagram of the present invention.
Reference numeral：1- protection circuits, 2- input filter circuits, 3- current rectifying and wave filtering circuits, 4- master power switch pipe circuits,
Negative-feedback circuit, 8- control circuits, 9- discharge circuits is isolated in 5- isolated buck circuits, 6- output rectifier and filters, 7-.
Specific implementation mode
With reference to embodiments and its attached drawing is further non-limitingly described in detail technical solution of the present invention.
As illustrated in fig. 1 and 2, a kind of switching power circuit, including sequentially connected protection circuit 1, input filter circuit 2,
Current rectifying and wave filtering circuit 3, master power switch pipe circuit 4, isolated buck circuit 5 and output rectifier and filter 6；Output rectification filter
The output end of circuit 6 is dropped through sequentially connected isolation negative-feedback circuit 7, control circuit 8, master power switch pipe circuit 4 and isolation
Volt circuit 5 forms voltage negative feedback loop；Wherein：
Protection circuit is connect with 220V AC powers, for inhibiting the current or voltage of input power excessive, protects circuit
It is not burned；
Input filter circuit, for rectifying and wave-filtering electricity will to be transferred to after the high-frequency electromagnetic interference signal filtering in AC power
Road；
Current rectifying and wave filtering circuit is transferred to main power after more stable DC signal and opens for being converted to ac signal
Close pipe circuit；
Master power switch pipe circuit, for according to the pulse-width modulation PWM signal transmitted from control circuit, controlling main power and opening
The on or off for closing pipe carries out negative feedback control by voltage negative feedback loop, the friendship stable to isolated buck circuit output
Galvanic electricity signal；
Isolated buck circuit, for the alternating current of master power switch pipe circuit output to be depressured, and it is miscellaneous that high frequency is isolated
Output rectifier and filter and control circuit are transferred to after wave respectively；
Output rectifier and filter, alternating current for exporting isolated buck circuit export after rectifying and wave-filtering obtaining
Stable direct current, for externally exporting stable DC；
Negative-feedback circuit is isolated, for receiving the direct current exported by output rectifier and filter, passes through negative voltage feedback
Circuit carries out negative feedback control, and the DC voltage of output is made to keep stablizing；
Control circuit, the signal for receiving isolation negative-feedback circuit output carries out negative feedback control, and is opened to main power
Pipe circuit transmission pulse-width modulation PWM signal is closed, master power switch pipe circuit turn-on or shutdown are made.
Protection circuit 1 includes self- recoverage insurance F1 (T3.15A 250V), varistor MOV1 (10D-47K470V) and NTC
Thermistor NCT1 (NTC 5D-11)；Self- recoverage insures F1, varistor MOV1, NTC thermistor NCT1, AC power
(220V) is sequentially connected in series.Wherein, self- recoverage insurance F1 is for preventing circuital current excessive, and varistor MOV1 is for preventing from opening
Transient voltage is excessive, and NTC thermistor NCT1 is used for Anti-surging electric current.
Input filter circuit 2 includes X filter capacitors C1 (0.1UF), the mutual induction filter T1 for collectively constituting π type filter circuits
(common mode filtering inductance UU9.8), Y filter capacitor C2 and Y filter capacitors C3；The both ends of X filter capacitors C1 are separately connected protection electricity
Two output ends on road, two input terminals of mutual induction filter T1 are separately connected the both ends of X filter capacitors C1, mutual induction filter T1
Two output ends be grounded after Y filter capacitor C2 and Y filter capacitors C3 respectively, two output ends of mutual induction filter T1 also divide
Not Lian Jie current rectifying and wave filtering circuit two input terminals.
Current rectifying and wave filtering circuit 3 includes rectifier bridge D1 (KBL406) and filter capacitor C4 (150nF/400V)；Rectifier bridge D1's
Input terminal connects input filter circuit, and positive and negative the two poles of the earth of output end are separately connected the anode and cathode of filter capacitor C4；Filtered electrical
Hold the coupled capacitance C10 ground connection of anode of C4, the cathode of filter capacitor C4 is separately connected master power switch pipe circuit and ground connection；It is whole
Flow the direct current of the exportable 311V of filter circuit output end.
Master power switch pipe circuit 4 includes metal-oxide-semiconductor Q1 (9N90), pull-up resistor R1 (10K), metal-oxide-semiconductor driving circuit and RCT
Absorbing circuit；The grid of metal-oxide-semiconductor connects control circuit through metal-oxide-semiconductor driving circuit, and metal-oxide-semiconductor driving circuit is used for according to electric from control
The pulse-width modulation PWM signal that road is transmitted makes metal-oxide-semiconductor Q1 on or off；The source electrode of metal-oxide-semiconductor Q1 connects current rectifying and wave filtering circuit；MOS
The drain electrode of pipe Q1 connects isolated buck circuit through RCT absorbing circuits, and RCT absorbing circuits are for absorbing peak voltage and electric current；On
The both ends of pull-up resistor R1 are separately connected the grid and source electrode of metal-oxide-semiconductor Q1.
Metal-oxide-semiconductor driving circuit include triode Q2 (SS8550), triode Q3 (SS8550), diode D2 (1N4148),
Resistance R2, resistance R3, resistance R4, resistance R5；Diode D2 connect MOS with the anode common end after resistance R2 parallel connections through resistance R3
The grid of pipe Q1, cathode common end are connect with the poles E of the poles E of triode Q2 and triode Q3 respectively；Triode Q2 and triode
Signal output ends of the B of Q3 extremely jointly through resistance R5 connection control circuits；The poles C of triode Q2 are grounded；The poles C of triode Q3 pass through
The output end of resistance R4 connection isolated buck circuits.
RCT absorbing circuits include diode D6 (FR207), resistance R17 (200K) and capacitance C9；Resistance R17 and capacitance C9
The high frequency switch transformer T2 primary sides of anode common end after parallel connection through positive diode D6 connection isolated buck circuits it is different
Name end, cathode common end are separately connected the same of the drain electrode of metal-oxide-semiconductor Q1 and the high frequency switch transformer T2 primary sides of isolated buck circuit
Name end.
Isolated buck circuit 5 includes high frequency switch transformer T2；Master power switch pipe circuit and current rectifying and wave filtering circuit it is defeated
Outlet connects the primary side of high frequency switch transformer T2；The secondary side connection output rectification filter electricity of the first of high frequency switch transformer T2
Road；The Same Name of Ends ground connection on the secondary side of the second of high frequency switch transformer T2, different name end is after diode D3 (FR207) respectively again through opening
The input terminal of dynamic resistance R18 (120K) connection filter rectifiers, and access the feeder ear of control circuit.Start-up resistor R18
For powering on moment, circuit is made to enter self-oscillation.
Output rectifier and filter 6 includes diode D4 (BAV70), diode D5 (BAV70), resistance R6, resistance R7, electricity
Hold C5, capacitance C6, electrolytic capacitor C7 (1000uF/35V), electrolytic capacitor C8 (1000uF/35V) and inductance L1 (3.3uH)；High frequency
The Same Name of Ends on the secondary sides switch transformer T2 first and different name end are commonly connected to through positive diode D4 and diode D5 respectively
The DC output end anode of output rectifier and filter；Both ends are in parallel with diode D4 after resistance R6 connects with capacitance C5；Electricity
Both ends are in parallel with diode D5 after resistance R7 connects with capacitance C6；The Same Name of Ends on the secondary sides high frequency switch transformer T2 first is through inductance L1
Ground connection；Electrolytic capacitor C7 connect the direct current electricity output of output rectifier and filter with the anode common end after electrolytic capacitor C8 parallel connections
Rectify pole, cathode common end grounding；It is straight that the DC output end anode of output rectifier and filter can externally export stable 24V
Galvanic electricity.Resistance R6 connects with capacitance C5, resistance R7 connects with capacitance C6, and the two separately constitutes the resistance of diode D4 and diode D5
Hold absorbing circuit.
The present embodiment further includes discharge circuit 9；Discharge circuit 9 includes resistance R19, resistance R20, the resistance being connected in parallel
R21, resistance R22, the DC output end of the anode common end connection output rectifier and filter after parallel connection, the public termination of cathode
Ground.Discharge circuit is used to discharge the electric current of capacitance in output rectifier and filter, it is ensured that output stable DC.
It includes photo-coupler U1 (817) and voltage negative feedback circuit that negative-feedback circuit 7, which is isolated,；Voltage negative feedback circuit includes
Voltage stabilizing triode U2 (CJ431), potentiometer R8 (1K), resistance R9 (5.1K), resistance R10 (2K), resistance R11 (51K), resistance
R12 (1K), resistance R13 (1K) and capacitance C9；The poles C of voltage stabilizing triode U2 are grounded；The electricity that the poles E of voltage stabilizing triode U2 are concatenated
Resistance R12 connects the DC output end anode of output rectifier and filter with resistance R10；The poles B of voltage stabilizing triode U2 pass through successively
Potentiometer R8 and resistance R9 ground connection, and the anode of the DC output end through resistance R11 connection output rectifier and filters；Resistance
Both ends after R13 connects with capacitance C7 are separately connected the poles E and the poles B of voltage stabilizing triode U2；The anode input terminal of photo-coupler U1
The node between resistance R10 and resistance R12 is accessed, cathode input terminal connects the poles E of voltage stabilizing triode U2；Photo-coupler U1's is defeated
Outlet connects the Switching Power Supply control chip U3 of control circuit.
Control circuit 8 includes short-circuit protection circuit, current foldback circuit, power-down protection circuit, current sampling circuit, switch
Power supply control chip U3 (models：) and its peripheral circuit UC3843BD1R2G；Short-circuit protection circuit, current foldback circuit, power down
Protection circuit respectively be isolated negative-feedback circuit and Switching Power Supply control chip U3 connections；The input of current sampling circuit terminates
Enter between current rectifying and wave filtering circuit and master power switch pipe circuit, output end connecting valve power supply control chip U3；Switching Power Supply control
The output end of the feeder ear connection isolated buck circuit of coremaking piece U3.
Current sampling circuit includes resistance R14, resistance R15 and resistance R16；One end of resistance R14 is grounded, other end connection
The source electrode of the metal-oxide-semiconductor Q1 of master power switch pipe circuit；Resistance R15 connects master power switch pipe with one end after resistance R16 series connection
The source electrode of the metal-oxide-semiconductor Q1 of circuit, the other end connect control circuit.
A kind of course of work of above-mentioned switching power circuit：
By the cities 220V AC power access protection circuit, protection circuit by self- recoverage insure F1, varistor MOV1 and
NTC thermistor NCT1 inhibits the current or voltage of input power excessive, and circuit is protected not to be burned；Input filter circuit will be handed over
It is transferred to current rectifying and wave filtering circuit after high-frequency electromagnetic interference signal filtering in galvanic electricity source；Current rectifying and wave filtering circuit turns ac signal
It is transferred to master power switch pipe circuit after being changed to more stable DC signal；Master power switch pipe circuit is according to from control circuit
The pulse-width modulation PWM signal transmitted controls the on or off of master power switch pipe, is carried out by voltage negative feedback loop negative anti-
Feedback control, the ac signal stable to isolated buck circuit output；Isolated buck circuit is by master power switch pipe circuit output
Ac signal be depressured, and be transferred to output rectifier and filter and control circuit respectively after high frequency spurs are isolated；It is defeated
Go out output after the alternating current that isolated buck circuit exports is carried out rectifying and wave-filtering by current rectifying and wave filtering circuit and obtain stable direct current, uses
The electrical appliances such as electric pump are can be applied in externally output stable DC, the direct current.
The direct current of output rectifier and filter output, by by output rectifier and filter, isolation negative-feedback circuit, control
The voltage negative feedback loop that circuit and master power switch pipe circuit processed is formed carries out negative feedback control, makes the DC voltage of output
It keeps stablizing.
When the DC voltage of output rectifier and filter output increases, photo-coupler U1 conductings, to Switching Power Supply
The output duty cycle for controlling chip U3 output ends reduces, and the voltage of master power switch pipe circuit output reduces；When output rectification filter
When the DC voltage of wave circuit output reduces, photo-coupler U1 is not turned on, to Switching Power Supply control chip U3 output ends
Output duty cycle increases, and the voltage of master power switch pipe circuit output increases, in cycles, to make output rectifier and filter
The DC voltage of output keeps stablizing.
The signal that control circuit receives isolation negative-feedback circuit output carries out negative feedback control, by adjusting main work(is transferred to
The duty ratio of the pulse-width modulation PWM signal of rate switching tube circuit, so as to adjust power switch tube circuit turn-on or the time of shutdown,
And then the DC voltage of current rectifying and wave filtering circuit output is adjusted, make exported DC voltage keep stablizing.In addition, control electricity
Road includes short-circuit protection circuit, current foldback circuit, power-down protection circuit, has short-circuit protection, overcurrent protection and power down protection
Function.
Claims (10)
1. a kind of switching power circuit, it is characterised in that：Including sequentially connected protection circuit, input filter circuit, rectification filter
Wave circuit, master power switch pipe circuit, isolated buck circuit and output rectifier and filter；The output of output rectifier and filter
End forms voltage through sequentially connected isolation negative-feedback circuit, control circuit, master power switch pipe circuit and isolated buck circuit
Negative feedback loop；Wherein：
The protection circuit is connect with AC power, for inhibiting the current or voltage of input power excessive, protect circuit not by
It burns out；
The input filter circuit, for current rectifying and wave filtering circuit will to be transferred to after the electromagnetic interference signal filtering in AC power；
The current rectifying and wave filtering circuit is transferred to main power after more stable DC signal and opens for being converted to ac signal
Close pipe circuit；
The master power switch pipe circuit, for according to the pulse-width modulation PWM signal transmitted from control circuit, controlling main power and opening
The on or off for closing pipe carries out negative feedback control by voltage negative feedback loop, the friendship stable to isolated buck circuit output
Galvanic electricity signal；
The isolated buck circuit, for the alternating current of master power switch pipe circuit output to be depressured, and it is miscellaneous that high frequency is isolated
Output rectifier and filter and control circuit are transferred to after wave respectively；
The output rectifier and filter, alternating current for exporting isolated buck circuit export after rectifying and wave-filtering obtaining
Stable direct current；
The isolation negative-feedback circuit passes through negative voltage feedback for receiving the direct current exported by output rectifier and filter
Circuit carries out negative feedback control, and the DC voltage of output is made to keep stablizing；
The control circuit, the signal for receiving isolation negative-feedback circuit output carries out negative feedback control, and is opened to main power
Pipe circuit transmission pulse-width modulation PWM signal is closed, master power switch pipe circuit turn-on or shutdown are made.
2. a kind of switching power circuit according to claim 1, it is characterised in that：The protection circuit includes that self- recoverage is protected
Dangerous F1, varistor MOV1 and NTC thermistor NCT1；The self- recoverage insurance F1, varistor MOV1, NTC thermistor
NCT1, AC power are sequentially connected in series.
3. a kind of switching power circuit according to claim 1, it is characterised in that：The input filter circuit includes common
Form X filter capacitors C1, mutual induction filter T1, the Y filter capacitor C2 and Y filter capacitor C3 of π type filter circuits；X filter capacitors
The both ends of C1 are separately connected two output ends of protection circuit；Two output ends of mutual induction filter T1 connect current rectifying and wave filtering circuit
Two input terminals.
4. a kind of switching power circuit according to claim 1, it is characterised in that：The current rectifying and wave filtering circuit includes rectification
Bridge D1 and filter capacitor C4；The input terminal of the rectifier bridge D1 connects input filter circuit, and positive and negative the two poles of the earth of output end connect respectively
Connect the anode and cathode of filter capacitor C4；The coupled capacitance C10 ground connection of anode of filter capacitor C4, the cathode point of filter capacitor C4
It Lian Jie not master power switch pipe circuit and ground connection.
5. a kind of switching power circuit according to claim 1, it is characterised in that：The master power switch pipe circuit includes
Metal-oxide-semiconductor Q1, pull-up resistor R1, metal-oxide-semiconductor driving circuit and RCT absorbing circuits；The grid of the metal-oxide-semiconductor is through metal-oxide-semiconductor driving circuit
Control circuit is connected, metal-oxide-semiconductor driving circuit is used to make metal-oxide-semiconductor Q1 lead according to the pulse-width modulation PWM signal transmitted from control circuit
Logical or shutdown；The source electrode of metal-oxide-semiconductor Q1 connects current rectifying and wave filtering circuit；The drain electrode of metal-oxide-semiconductor Q1 connects isolated buck through RCT absorbing circuits
Circuit, RCT absorbing circuits are for absorbing peak voltage and electric current；The both ends of pull-up resistor R1 are separately connected the grid of metal-oxide-semiconductor Q1
And source electrode.
6. a kind of switching power circuit according to claim 5, it is characterised in that：The metal-oxide-semiconductor driving circuit includes three
Pole pipe Q2, triode Q3, diode D2, resistance R2, resistance R3, resistance R4, resistance R5；The diode D2 is in parallel with resistance R2
Grid of the anode common end afterwards through resistance R3 connection metal-oxide-semiconductors Q1, cathode common end respectively with the poles E of triode Q2 and triode
The poles E of Q3 connect；Triode Q2 extremely connects control circuit through resistance R5 jointly with the B of triode Q3；The poles C of triode Q2 connect
Ground；Output end of the poles C of triode Q3 through resistance R4 connection isolated buck circuits.
The RCT absorbing circuits include diode D6, resistance R17 and capacitance C9；Anode after resistance R17 is in parallel with capacitance C9 is public
An input terminal of the end through positive diode D6 connection isolated buck circuits altogether, cathode common end is separately connected metal-oxide-semiconductor Q1's
Another input terminal of drain electrode and connection isolated buck circuit.
7. a kind of switching power circuit according to claim 1, it is characterised in that：The isolated buck circuit includes high frequency
Switch transformer T2；Master power switch pipe circuit connects the original of high frequency switch transformer T2 with the output end of current rectifying and wave filtering circuit
Side；The secondary side of the first of high frequency switch transformer T2 connects output rectifier and filter；The secondary side of the second of high frequency switch transformer T2
Same Name of Ends ground connection, different name end input terminal of activated resistance R18 connections filter rectifier again respectively after diode D3, with
And the feeder ear of access control circuit.
8. a kind of switching power circuit according to claim 1, it is characterised in that：The output rectifier and filter includes
Diode D4, diode D5, resistance R6, resistance R7, capacitance C5, capacitance C6, electrolytic capacitor C7, electrolytic capacitor C8 and inductance L1；
The Same Name of Ends on the secondary sides the high frequency switch transformer T2 first and different name end are total through positive diode D4 and diode D5 respectively
With the DC output end anode for being connected to output rectifier and filter；Both ends and diode D4 after resistance R6 connects with capacitance C5
It is in parallel；Both ends are in parallel with diode D5 after resistance R7 connects with capacitance C6；The Same Name of Ends on the secondary sides high frequency switch transformer T2 first
It is grounded through inductance L1；Electrolytic capacitor C7 connect the straight of output rectifier and filter with the anode common end after electrolytic capacitor C8 parallel connections
Galvanic electricity output head anode, cathode common end grounding.
9. a kind of switching power circuit according to claim 1, it is characterised in that：The isolation negative-feedback circuit includes light
Coupler U1 and voltage negative feedback circuit；The voltage negative feedback circuit include voltage stabilizing triode U2, potentiometer R8, resistance R9,
Resistance R10, resistance R11, resistance R12, resistance R13 and capacitance C9；The poles C of the voltage stabilizing triode U2 are grounded；Voltage stabilizing triode
The resistance R12 that the poles E of U2 are concatenated connects the DC output end anode of output rectifier and filter with resistance R10；Voltage stabilizing three
The poles B of pole pipe U2 are successively through potentiometer R8 and resistance R9 ground connection, and the direct current through resistance R11 connection output rectifier and filters
Electricity output rectifies pole；Both ends after resistance R13 connects with capacitance C7 are separately connected the poles E and the poles B of voltage stabilizing triode U2；Optical coupling
Node between the anode input terminal access resistance R10 and resistance R12 of device U1, cathode input terminal connect the E of voltage stabilizing triode U2
Pole；The output end of photo-coupler U1 connects control circuit.
10. a kind of switching power circuit according to claim 1, it is characterised in that：The control circuit includes that short circuit is protected
Protection circuit, current foldback circuit, power-down protection circuit, current sampling circuit, Switching Power Supply control chip U3 and its peripheral circuit；
The short-circuit protection circuit, current foldback circuit, power-down protection circuit respectively with negative-feedback circuit and Switching Power Supply control is isolated
The U3 connections of coremaking piece；Between one end access current rectifying and wave filtering circuit and master power switch pipe circuit of current sampling circuit, the other end
Connecting valve power supply control chip U3；Switching Power Supply controls the output end of the feeder ear connection isolated buck circuit of chip U3.
The current sampling circuit includes resistance R14, resistance R15 and resistance R16；One end of resistance R14 is grounded, other end connection
Master power switch pipe circuit；Resistance R15 connects master power switch pipe circuit, other end connection with one end after resistance R16 series connection
Control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810333152.1A CN108336917A (en) | 2018-04-13 | 2018-04-13 | A kind of switching power circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810333152.1A CN108336917A (en) | 2018-04-13 | 2018-04-13 | A kind of switching power circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108336917A true CN108336917A (en) | 2018-07-27 |
Family
ID=62934197
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810333152.1A Pending CN108336917A (en) | 2018-04-13 | 2018-04-13 | A kind of switching power circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108336917A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109039089A (en) * | 2018-08-21 | 2018-12-18 | 珠海瑞捷电气股份有限公司 | The isolating switch power of super wide voltage input |
| CN109947688A (en) * | 2019-04-03 | 2019-06-28 | 昆山通达测科电子科技有限公司 | UART/I2C bus programmable pulls up voltage control circuit |
| CN113541458A (en) * | 2021-05-31 | 2021-10-22 | 广州金升阳科技有限公司 | Filter circuit |
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| CN109947688A (en) * | 2019-04-03 | 2019-06-28 | 昆山通达测科电子科技有限公司 | UART/I2C bus programmable pulls up voltage control circuit |
| CN113541458A (en) * | 2021-05-31 | 2021-10-22 | 广州金升阳科技有限公司 | Filter circuit |
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