CN208226890U - A kind of switching power circuit - Google Patents
A kind of switching power circuit Download PDFInfo
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- CN208226890U CN208226890U CN201820527400.1U CN201820527400U CN208226890U CN 208226890 U CN208226890 U CN 208226890U CN 201820527400 U CN201820527400 U CN 201820527400U CN 208226890 U CN208226890 U CN 208226890U
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Abstract
The utility model 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 direct current that the AC power source of power grid can be become to stablize output by the utility model is used for the power supply of the electrical appliances such as electric pump；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 utility model belongs to technical field of circuit control, and in particular to a kind of switching power circuit.
Background technique
Electric pump is with the pump for all kinds of liquid mediums of all kinds of conveyings being driven by electricity, 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.
Existing exchange turns the generally existing following defect of switching power circuit of 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.
Utility model content
The purpose of this utility model is that being directed to the above problem in the prior art, a kind of switching power circuit, energy are provided
Enough direct currents that the AC power source of power grid is become stable output are used for the electrical appliances such as electric pump and are powered, and strong interference immunity makes
With safety.
To realize above-mentioned purpose of utility model, the utility model is adopted the technical scheme that
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 source, 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 source
Road；
The current rectifying and wave filtering circuit, for being transferred to main function after ac signal is converted to more stable DC signal
Rate switching tube circuit；
The master power switch pipe circuit, for controlling main function according to the pulse-width modulation PWM signal transmitted from control circuit
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
Feedback loop 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 carry out negative feedback control, and to main function
Rate switching tube circuit transmission pulse-width modulation PWM signal, makes master power switch pipe circuit on or off.
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 source are sequentially connected in series.
Above-mentioned input filter circuit includes the X filter capacitor C1 for collectively constituting π type filter circuit, the filter of mutual induction filter T1, Y
Wave capacitor C2 and Y filter capacitor C3；The both ends of X filter capacitor 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 of the rectifier bridge D1 connects input
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
Capacitor 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 circuit, and RCT absorbing circuit is 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；Anode common end after the diode D2 is in parallel with resistance R2 connect the grid of metal-oxide-semiconductor Q1 through resistance R3, and cathode is public
End is connect with the pole E of the pole 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 circuit；The pole C of triode Q2 is grounded；Output of the pole C of triode Q3 through resistance R4 connection isolated buck circuit
End.
The RCT absorbing circuit includes diode D6, resistance R17 and capacitor C9；Sun after resistance R17 is in parallel with capacitor C9
An input terminal of the pole common end through positive diode D6 connection isolated buck circuit, 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
The primary side of output end connection 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 rectifier, and the feeder ear of access control circuit.
Above-mentioned output rectifier and filter includes diode D4, diode D5, resistance R6, resistance R7, capacitor C5, capacitor
C6, electrolytic capacitor C7, electrolytic capacitor C8 and inductance L1；The Same Name of Ends on the secondary side 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 capacitor C5；Both ends are in parallel with diode D5 after resistance R7 connects with capacitor C6；
The Same Name of Ends on the secondary side 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 pressure stabilizing triode U2, potentiometer R8, resistance R9, resistance R10, resistance R11, resistance R12, resistance R13 and capacitor C9；It is described steady
Press the pole the C ground connection of triode U2；The resistance R12 that the pole E of pressure stabilizing triode U2 is concatenated connects output rectification filter with resistance R10
The DC output end anode of circuit；The pole B of pressure stabilizing triode U2 is successively grounded through potentiometer R8 and resistance R9, and through resistance
The DC output end anode of R11 connection output rectifier and filter；Both ends after resistance R13 connects with capacitor C7 are separately connected
The pole E and the pole B of pressure stabilizing triode U2；Node between the anode input terminal access resistance R10 and resistance R12 of photo-coupler U1,
The pole E of cathode input terminal connection pressure 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 be isolated negative-feedback circuit and Switching Power Supply control chip U3 connection；Current rectifying and wave filtering circuit is accessed in one end of current sampling circuit
Between master power switch pipe circuit, other end connection switch power supply control chip U3；The power supply of Switching Power Supply control 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；One end after resistance R15 connects with resistance R16 connects master power switch pipe circuit, the other end
Connect control circuit.
Compared with the prior art, the advantage of the utility model is:
A kind of switching power circuit provided by the utility model can become the AC power source of power grid to stablize the straight of output
Galvanic electricity is powered for electrical appliances such as electric pumps；And the output end of output rectifier and filter is negative anti-through sequentially connected isolation
Current feed circuit, control circuit, master power switch pipe circuit and isolated buck circuit form voltage negative feedback loop, can not only filter
Fall the high-frequency interferencing signal in input power, can also stablize the voltage of output direct current by voltage negative feedback loop, be adopted
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 utility model is applicable in various electric pumps, such as water pump, oil pump, concrete pump, can
Using direct current or a variety of power supplies of exchange, reliable and stable direct current is exported, strong interference immunity ensure that the safety of power supply
Property.
Detailed description of the invention
Fig. 1 is the circuit module block diagram of the utility model.
Fig. 2 is the circuit diagram of the utility model.
Appended drawing reference: 1- protection circuit, 2- input filter circuit, 3- current rectifying and wave filtering circuit, 4- master power switch pipe circuit,
Negative-feedback circuit, 8- control circuit, 9- discharge circuit is isolated in 5- isolated buck circuit, 6- output rectifier and filter, 7-.
Specific embodiment
With reference to embodiments and its attached drawing is further non-limitingly described in detail technical solutions of the utility model.
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 power source, 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 source
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 controlling main power and opening according to the pulse-width modulation PWM signal transmitted from control circuit
The on or off for closing pipe carries out negative feedback control by voltage negative feedback loop, stable friendship is exported to isolated buck circuit
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 opens to main power
Pipe circuit transmission pulse-width modulation PWM signal is closed, master power switch pipe circuit on or off is 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 source
(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 capacitor C1 (0.1UF), the mutual induction filter T1 for collectively constituting π type filter circuit
(common mode filtering inductance UU9.8), Y filter capacitor C2 and Y filter capacitor C3；The both ends of X filter capacitor 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 capacitor C1, mutual induction filter T1
Two output ends be grounded after Y filter capacitor C2 and Y filter capacitor 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 capacitor 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 circuit, and RCT absorbing circuit is 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；Anode common end after diode D2 is in parallel with resistance R2 connect MOS through resistance R3
The grid of pipe Q1, cathode common end are connect with the pole E of the pole E of triode Q2 and triode Q3 respectively；Triode Q2 and triode
Signal output end of the B of Q3 extremely jointly through resistance R5 connection control circuit；The pole C of triode Q2 is grounded；The pole C of triode Q3 passes through
The output end of resistance R4 connection isolated buck circuit.
RCT absorbing circuit includes diode D6 (FR207), resistance R17 (200K) and capacitor C9；Resistance R17 and capacitor C9
The high frequency switch transformer T2 primary side of anode common end after parallel connection through positive diode D6 connection isolated buck circuit 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 side 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
The primary side of outlet connection 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 rectifier, and the feeder ear of access 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, capacitor 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 side 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 capacitor C5；Electricity
Both ends are in parallel with diode D5 after resistance R7 connects with capacitor C6；The Same Name of Ends on the secondary side high frequency switch transformer T2 first is through inductance L1
Ground connection；Anode common end after electrolytic capacitor C7 is in parallel with electrolytic capacitor C8 connect the direct current electricity output of output rectifier and filter
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 capacitor C5, resistance R7 connects with capacitor 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, the resistance R20, 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 capacitor 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
Pressure stabilizing triode U2 (CJ431), potentiometer R8 (1K), resistance R9 (5.1K), resistance R10 (2K), resistance R11 (51K), resistance
R12 (1K), resistance R13 (1K) and capacitor C9；The pole C of pressure stabilizing triode U2 is grounded；The electricity that the pole E of pressure stabilizing triode U2 is concatenated
Resistance R12 connects the DC output end anode of output rectifier and filter with resistance R10；The pole B of pressure stabilizing triode U2 successively passes through
Potentiometer R8 and resistance R9 ground connection, and the anode of the DC output end through resistance R11 connection output rectifier and filter；Resistance
Both ends after R13 connects with capacitor C7 are separately connected the pole E and the pole B of pressure 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 pole E of pressure stabilizing triode U2；Photo-coupler U1's is defeated
The Switching Power Supply that outlet connects control circuit controls chip U3.
Control circuit 8 includes short-circuit protection circuit, current foldback circuit, power-down protection circuit, current sampling circuit, switch
Power supply control chip U3 (model: UC3843BD1R2G) and its peripheral circuit；Short-circuit protection circuit, current foldback circuit, power down
Protection circuit respectively with negative-feedback circuit and Switching Power Supply be isolated control chip U3 connection；The input of current sampling circuit terminates
Enter between current rectifying and wave filtering circuit and master power switch pipe circuit, output end connection switch 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；One end after resistance R15 connects with resistance R16 connects master power switch pipe
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 city 220V AC power source access protection circuit, protection circuit by self- recoverage insurance 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
Current rectifying and wave filtering circuit is transferred to after high-frequency electromagnetic interference signal filtering in galvanic electricity source；Current rectifying and wave filtering circuit turns ac signal
Master power switch pipe circuit is transferred to 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, stable ac signal is exported to isolated buck circuit；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
Output obtains stable direct current after the alternating current that isolated buck circuit exports is carried out rectifying and wave-filtering by current rectifying and wave filtering circuit out, uses
It can be applied to the electrical appliances such as electric pump 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 conducting, thus Switching Power Supply
The output duty cycle for controlling chip U3 output end 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, thus Switching Power Supply control chip U3 output end
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 function is transferred to
The duty ratio of the pulse-width modulation PWM signal of rate switching tube circuit, so as to adjust the time of power switch tube circuit on or off,
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 source, 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 source；
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 controlling main power and opening according to the pulse-width modulation PWM signal transmitted from control circuit
The on or off for closing pipe carries out negative feedback control by voltage negative feedback loop, stable friendship is exported to isolated buck circuit
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 opens to main power
Pipe circuit transmission pulse-width modulation PWM signal is closed, master power switch pipe circuit on or off is 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 insures F1, varistor MOV1, NTC thermistor
NCT1, AC power source 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 capacitor C1, mutual induction filter T1, the Y filter capacitor C2 and Y filter capacitor C3 of π type filter circuit；X filter capacitor
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 capacitor C10 ground connection of the 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 circuit；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 circuit
Circuit, RCT absorbing circuit is 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-semiconductor Q1, cathode common end respectively with the pole E of triode Q2 and triode
The pole E of Q3 connects；Triode Q2 extremely connects control circuit through resistance R5 jointly with the B of triode Q3；The pole C of triode Q2 connects
Ground；Output end of the pole C of triode Q3 through resistance R4 connection isolated buck circuit；
The RCT absorbing circuit includes diode D6, resistance R17 and capacitor C9；Anode after resistance R17 is in parallel with capacitor C9 is public
An input terminal of the end through positive diode D6 connection isolated buck circuit 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 connection 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 7, it is characterised in that: the output rectifier and filter includes
Diode D4, diode D5, resistance R6, resistance R7, capacitor C5, capacitor C6, electrolytic capacitor C7, electrolytic capacitor C8 and inductance L1；
The Same Name of Ends on the secondary side 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 capacitor C5
It is in parallel；Both ends are in parallel with diode D5 after resistance R7 connects with capacitor C6；The Same Name of Ends on the secondary side high frequency switch transformer T2 first
It is grounded through inductance L1；Anode common end after electrolytic capacitor C7 is in parallel with electrolytic capacitor C8 connect the straight of output rectifier and filter
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 pressure stabilizing triode U2, potentiometer R8, resistance R9,
Resistance R10, resistance R11, resistance R12, resistance R13 and capacitor C9；The pole C of the pressure stabilizing triode U2 is grounded；Pressure stabilizing triode
The resistance R12 that the pole E of U2 is concatenated connects the DC output end anode of output rectifier and filter with resistance R10；Pressure stabilizing three
The pole B of pole pipe U2 is successively grounded through potentiometer R8 and resistance R9, and the direct current through resistance R11 connection output rectifier and filter
Electricity output rectifies pole；Both ends after resistance R13 connects with capacitor C7 are separately connected the pole E and the pole B of pressure 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 pressure 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 connection 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
Connection switch 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；One end after resistance R15 connects with resistance R16 connects master power switch pipe circuit, other end connection
Control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820527400.1U CN208226890U (en) | 2018-04-13 | 2018-04-13 | A kind of switching power circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820527400.1U CN208226890U (en) | 2018-04-13 | 2018-04-13 | A kind of switching power circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208226890U true CN208226890U (en) | 2018-12-11 |
Family
ID=64529108
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820527400.1U Expired - Fee Related CN208226890U (en) | 2018-04-13 | 2018-04-13 | A kind of switching power circuit |
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| Country | Link |
|---|---|
| CN (1) | CN208226890U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108336917A (en) * | 2018-04-13 | 2018-07-27 | 王晓 | A kind of switching power circuit |
| CN116260349A (en) * | 2022-12-14 | 2023-06-13 | 航天深拓(北京)科技有限公司 | AC/DC switching power supply |
-
2018
- 2018-04-13 CN CN201820527400.1U patent/CN208226890U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108336917A (en) * | 2018-04-13 | 2018-07-27 | 王晓 | A kind of switching power circuit |
| CN116260349A (en) * | 2022-12-14 | 2023-06-13 | 航天深拓(北京)科技有限公司 | AC/DC switching power supply |
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| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
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| CF01 | Termination of patent right due to non-payment of annual fee |