CN203590041U - Flyback step-up protection circuit - Google Patents
Flyback step-up protection circuit Download PDFInfo
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- CN203590041U CN203590041U CN201320541902.7U CN201320541902U CN203590041U CN 203590041 U CN203590041 U CN 203590041U CN 201320541902 U CN201320541902 U CN 201320541902U CN 203590041 U CN203590041 U CN 203590041U
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Abstract
The utility model provides a flyback step-up protection circuit. The protection circuit comprises a power supply module, a transformation module, a direct-current rectification and filtering module, a switch module, a control module and a feedback module. A first voltage-regulator tube is added to the circuit, and is connected with an optical coupling circuit in series. By setting a first voltage-regulating parameter reasonably, the limit use voltage of a control chip TL431 in the optical coupling circuit can be greatly increased, so that when the use voltage is higher than the limit use voltage of the control chip TL431, the use voltage of the circuit is enabled to meet the requirement by connecting in series with the first voltage-regulator tube having a voltage equal to the difference between the use voltage and the limit use voltage of the control chip. Besides, the circuit is simple and reliable, and is low in cost.
Description
Technical field
The utility model relates to circuit protection technical field, particularly relates to a kind of flyback supercharging protective circuit.
Background technology
When circuit of reversed excitation refers to the conducting of main circuit switching tube, secondary side diode turn-offs, transformer energy storage; When main switch turn-offs, secondary side diode current flow, the circuit that transformer energy storage discharges to load.
At present; conventional pulse width modulation mode carries out power supply overvoltage protection; in circuit, the Voltage Feedback of late-class circuit is to the pressure feedback port of pulse width modulating chip; after the voltage signal of feedback and inner reference voltage being compared by pulse width modulating chip again, by pulse width modulating chip, controlled conducting and the disconnection of metal-oxide-semiconductor.
The control chip TL431 arranging in late-class circuit has corresponding limiting voltage; in feedback module, different magnitudes of voltage can be detected; when running into the magnitude of voltage detecting and be greater than the limiting voltage of control chip TL431; conventionally can adopt independent power supply to power to TL431, so that the voltage of TL431 meets the requirement of detected voltage.
But, adopt independent power supply to power and increased the complexity of circuit to TL431, increased cost.
Summary of the invention
Based on this, the utility model is to overcome the defect of prior art, and the flyback supercharging that a kind of circuit is simple and reliable, cost is low protective circuit is provided.
Its technical scheme is as follows:
A kind of flyback supercharging protective circuit, comprise power module, voltage changing module, direct current rectification filtering module, switch module, control module and feedback module, described voltage changing module comprises input winding and output winding, and described input winding interacts with output winding; The Same Name of Ends of described input winding is connected with the output of described power module, the different name end of described input winding is connected with the input of described switch module, the input of described control module is connected with the output of described switch module, the output of described control module is connected with the control end of switch module, and the output head grounding of described switch module; The different name end of described output winding is connected with described direct current rectification filtering module, the Same Name of Ends ground connection of described output winding; The input of described feedback module connects described direct current rectification filtering module, and the output of described feedback module is connected with described control module; Described control module comprises pulse width modulating chip, sampling resistor, timing resistor and timing capacitor, the voltage sample end of described pulse width modulating chip and the output of described switch module are all connected one end of described sampling resistor, the other end ground connection of described sampling resistor; Described timing resistor and timing capacitor are connected in series, the timing end of described pulse width modulating chip is connected with the common port of described timing resistor and timing capacitor, the other end of described timing resistor is connected with the reference voltage terminal of described pulse width modulating chip, the other end ground connection of described timing capacitor, the earth terminal ground connection of described pulse width modulating chip; The output of described pulse width modulating chip is connected with the control end of described switch module, and the power end of described pulse width modulating chip is connected with the output of described power module; Described feedback module comprises the first voltage-stabiliser tube and optocoupler loop, described the first voltage-stabiliser tube is connected with described optocoupler loop, the one end in the negative electrode of described the first voltage-stabiliser tube and described optocoupler loop is all connected with the output of described direct current rectification filtering module, the anode of described the first voltage-stabiliser tube links with the other end in described optocoupler loop, and described optocoupler loop ground connection.
Below further technical scheme is described:
Described optocoupler loop comprises optocoupler, control chip, the first current-limiting resistance, the first divider resistance and the second divider resistance; Described optocoupler comprises reflector and receiver, the input of described reflector is connected with described first current-limiting resistance one end, the anodic bonding of the other end of described the first current-limiting resistance and described the first voltage-stabiliser tube, the negative electrode of described the first voltage-stabiliser tube is connected with the output of described direct current rectification filtering module, and the output of described reflector is connected with the input of described control chip; The input of described receiver is connected with the frequency compensation end of described pulse width modulating chip, the output head grounding of described receiver; Described the first divider resistance and the second divider resistance are connected in series, the control end of described control chip is connected with the common port of the second divider resistance with described the first divider resistance, the other end of described the first divider resistance is connected with the output of described direct current rectification filtering module, the other end ground connection of described the second divider resistance, the output head grounding of described control chip; Described control chip is in VD conducting during higher than its voltage threshold.
Described optocoupler loop also comprises building-out capacitor and the first filter capacitor; The two ends of described building-out capacitor are connected with control end with the input of described control chip respectively, and described the first filter capacitor and described the second divider resistance are connected in parallel.
Also comprise the first biasing resistor and the second biasing resistor, the two ends of described the first biasing resistor connect respectively reference voltage terminal and the voltage sample end of described pulse width modulating chip; The two ends of described the second biasing resistor connect respectively the output of described power module and the voltage sample end of described pulse width modulating chip.
Described voltage changing module also comprises feedback winding, the first resistance, the first diode, the first electric capacity and the second voltage-stabiliser tube, described feedback winding is responded to the voltage of described output winding, the different name end of described feedback winding is connected with the positive pole of described the first diode, the negative pole of described the first diode is connected with one end of described the first resistance, the Same Name of Ends ground connection of described feedback winding, the common port of the other end of described the first resistance and one end of described the first electric capacity is connected with the negative electrode of described the second voltage-stabiliser tube and the power end of described pulse width modulating chip, the other end of described the first electric capacity is connected with the Same Name of Ends of described feedback winding, the voltage sample end of described pulse width modulating chip is connected the anode of described the second voltage-stabiliser tube with the common port of described the second biasing resistor.
Described direct current rectification filtering module comprises the second diode and the second filter capacitor, the positive pole of described the second diode is connected with the different name end of described output winding, the negative pole of described the second diode is the output of described direct current rectification filtering module, described second filter capacitor one end is connected with the negative pole of described the second diode, described the second filter capacitor other end ground connection.
Described direct current rectification filtering module also comprises the second resistance, the 3rd filter capacitor, the first filter inductance, the 4th filter capacitor and the 3rd resistance; The two ends of described the second resistance are connected with one end of described the 3rd filter capacitor with the positive pole of described the second diode respectively, and the other end of described the 3rd filter capacitor is connected with the negative pole of described the second diode; The two ends of described the first filter inductance are connected with one end of described the 4th filter capacitor with the positive pole of described the second filter capacitor respectively, and the other end of described the 4th filter capacitor is connected with the negative pole of described the second filter capacitor; Described the 3rd resistance is in parallel with described the 4th filter capacitor.
Described switch module comprises N-channel MOS FET, the 3rd biasing resistor, the second current-limiting resistance and the 5th filter capacitor, the drain electrode of described N-channel MOS FET is the input of described switch module, the source electrode of described N-channel MOS FET is the output of described switch module, the grid of described N-channel MOS FET is the control end of described switch module, and the grid of described N-channel MOS FET is connected with the output of described pulse width modulating chip by described the second current-limiting resistance, described the 3rd biasing resistor is connected between the grid and source electrode of described N-channel MOS FET; The two ends of described the 5th filter capacitor are connected with source electrode with the drain electrode of described N-channel MOS FET respectively.
Described control module comprises filter unit, and described filter unit comprises filter resistance and the 6th filter capacitor, and the two ends of described filter resistance connect respectively the output of described switch module and the voltage sample end of described pulse width modulating chip; One end of described the 6th filter capacitor connects the voltage sample end of described pulse width modulating chip, other end ground connection.
Described power module comprises the 7th filter capacitor, the 8th filter capacitor, the second filter inductance, the 3rd diode, the 4th diode, the 4th resistance, the 5th resistance and triode; Described the 7th filter capacitor one end is connected with voltage input end, other end ground connection; Described the second filter inductance input is connected with voltage input end, and output is connected with described the 8th filter capacitor one end, described the 8th filter capacitor other end ground connection; Described the 3rd diode, the 4th diode and the 4th resistance are connected in series, and be connected in parallel with described the 8th filter capacitor, the positive pole of described the 3rd diode is connected with described the 8th filter capacitor one end, and described the 4th resistance one end is connected with described the 8th filter capacitor other end; Described the 5th resistance one end is connected with the positive pole of described the 3rd diode, the other end is connected with the emitter of described triode, the base stage of described triode is connected with the negative pole of described the 4th diode, and the collector electrode of described triode is connected with the negative electrode of described the second voltage-stabiliser tube and the power end of described pulse width modulating chip.
Below the principle of aforementioned techniques scheme, effect etc. are described:
In circuit, add the first voltage-stabiliser tube, and the first voltage-stabiliser tube is connected with optocoupler loop, by setting rational the first voltage stabilizing parameter, can greatly expand the limit of control chip TL431 in optocoupler loop and use voltage, when the limit of using voltage to be greater than control chip TL431 is used voltage, the magnitude of voltage of connecting, for using voltage and the control chip limit to use the first voltage-stabiliser tube of the difference of voltage, can make the use voltage of circuit reach requirement, circuit is simple and reliable, and cost is low.
Accompanying drawing explanation
Fig. 1 is the circuit theory diagrams of the utility model flyback supercharging protective circuit;
Fig. 2 is the inside theory diagram of pulse width modulating chip UC3843.
Description of reference numerals:
100. flyback supercharging protective circuits, 110. power modules, 120. voltage changing modules, 140. switch modules; 130. direct current rectification filtering modules, 150. feedback modules, 160. control modules, 162. filter units; 210. error amplifiers, 220. comparators, 230.PWM latch.
Embodiment
Below embodiment of the present utility model is elaborated:
As shown in Figure 1, a kind of flyback supercharging protective circuit 100, comprises power module 110; Voltage changing module 120, for carrying out step-down to the rectifying and wave-filtering voltage of power module 110 outputs; Direct current rectification filtering module 130, carries out rectifying and wave-filtering and exports VD from the output of direct current rectification filtering module 130 for the rectifying and wave-filtering voltage to after step-down; Switch module 140, for rectification filtering module is carried out to switch control, thereby obtains stable magnitude of voltage; Feedback module 150, for gathering VD; And control module 160.Voltage changing module 120 comprises input winding T1Aa-b and output winding T1Ae-f, and input winding T1Aa-b interacts with output winding T1Ae-f; The Same Name of Ends T1Aa of input winding T1Aa-b is connected with the input of switch module 140 with the different name end T1Ab that the output of power module 110 is connected, inputs winding T1Aa-b, the input of control module 160 is connected with the output of switch module 140, the output of control module 160 is connected with the control end of switch module 140, and the output head grounding of switch module 140; The different name end T1Ae of output winding T1Ae-f is connected with direct current rectification filtering module 130, the Same Name of Ends T1Af ground connection of output winding T1Ae-f.The input of feedback module 150 connects direct current rectification filtering module 130, the output of feedback module 150 is connected with control module 160, feedback module 150 sends feedback signal in VD during higher than voltage threshold, and the current potential of frequency compensation end COMP is dragged down.Control module 160 comprises pulse width modulating chip U1, sampling resistor R5, timing resistor R11 and timing capacitor C4, as shown in Figure 2, voltage sample end Ics and the output of switch module 140 of pulse width modulating chip U1 is all connected one end of sampling resistor R5, the other end ground connection of sampling resistor R5; Timing resistor R11 and timing capacitor C4 are connected in series, the timing end RT/CT of pulse width modulating chip U1 is connected with the common port of timing capacitor C4 with timing resistor R11, the other end of timing resistor R11 is connected with the reference voltage terminal Verf of pulse width modulating chip U1, the other end ground connection of timing capacitor C4, the earth terminal Gnd ground connection of pulse width modulating chip U1; The output Output of pulse width modulating chip U1 is connected with the control end of switch module 140, and the power end Vcc of pulse width modulating chip U1 is connected with the output of power module 110.The model of pulse width modulating chip U1 in the present embodiment is UC3843.
Described feedback module 150 comprises the first voltage-stabiliser tube ZE2 and optocoupler loop, described the first voltage-stabiliser tube ZE2 connects with described optocoupler loop, the one end in the negative electrode of described the first voltage-stabiliser tube ZE2 and described optocoupler loop is all connected with the output of described direct current rectification filtering module 130, the anode of described the first voltage-stabiliser tube ZE2 links with the other end in described optocoupler loop, and described optocoupler loop ground connection.
In circuit, add the first voltage-stabiliser tube ZE2, and the first voltage-stabiliser tube ZE2 is connected with optocoupler loop, by setting rational the first voltage stabilizing parameter, can greatly expand the limit of control chip TL431 in optocoupler loop and use voltage, when the limit of using voltage to be greater than control chip TL431 is used voltage, the magnitude of voltage of connecting, for using voltage and the control chip limit to use the first voltage-stabiliser tube ZE2 of the difference of voltage, can make the use voltage of circuit reach requirement, circuit is simple and reliable, and cost is low.
When the limiting voltage of control chip TL431 is 40V, if need to detect while being greater than the voltage of 40V, just can not directly use; As: it is 40V that the limit of control chip TL431 is used voltage, the first voltage-stabiliser tube ZE2 of a 15V of series connection, the use voltage of control chip TL431 just can reach 55V so, if the first voltage-stabiliser tube ZE2 of a 100V of series connection, the use voltage of control chip TL431 just can reach 140V so.
As shown in Figure 1, in an embodiment, optocoupler loop comprises optocoupler U3, control chip U2, the first current-limiting resistance R8, the first divider resistance R7 and the second divider resistance R4 therein.In the present embodiment, control chip U2 adopts TL431 chip, the control end that the reference edge of control chip U2 is control switch, the input that the negative electrode of control chip U2 is control switch, the output that the anode of control chip U2 is control switch.Optocoupler U3 comprises reflector U3A and receiver U3B; the input of described reflector U3A is connected with described first current-limiting resistance R8 one end; the anodic bonding of the other end of described the first current-limiting resistance R8 and described the first voltage-stabiliser tube ZE2, the negative electrode of described the first voltage-stabiliser tube ZE2 is connected with the output of described direct current rectification filtering module 130; The output of reflector U3A is connected with the input of control chip U2, and the input of receiver U3B is connected with the frequency compensation end COMP of pulse width modulating chip U1, the output head grounding of receiver U3B; The first divider resistance R7 and the second divider resistance R4 are connected in series, the control end of control chip U2 is connected with the common port of the second divider resistance R4 with the first divider resistance R7, the other end of the first divider resistance R7 is connected with the output of direct current rectification filtering module, the other end ground connection of the second divider resistance R4, the output head grounding of control chip U2; Control chip U2 is in VD conducting during higher than its voltage threshold.
In an embodiment, optocoupler loop also comprises building-out capacitor C22 and the first filter capacitor CR4 therein; The two ends of building-out capacitor C22 are connected with control end with the input of control chip U2 respectively, and the first filter capacitor CR4 and the second divider resistance R4 are connected in parallel.
In the present embodiment, the frequency compensation end COMP of pulse width modulating chip U1 can directly pass through receiver ground connection; be between receiver and compensation end COMP, other components and parts such as contact resistance not between receiver and ground wire; after receiver conducting, make frequency compensation end COMP current potential to drag down fast, make overcurrent protection reaction sensitiveer.
As shown in Figure 1, therein in an embodiment, also comprise the first biasing resistor R9 and the second biasing resistor R6, the two ends of the first biasing resistor R9 connect respectively reference voltage terminal Verf and the voltage sample end Ics of pulse width modulating chip U1, and the two ends of the second biasing resistor R6 connect respectively the output of power module 110 and the voltage sample end Ics of pulse width modulating chip U1.In circuit, add the first biasing resistor R9 and the second biasing resistor R6, be used to the voltage sample end Ics of pulse width modulating chip U1 that extra current offset is provided; The first biasing resistor R9 introduces power supply from the reference voltage terminal Verf of pulse width modulating chip U1, electric current through the first biasing resistor R9 flow through pulse width modulating chip U1 voltage sample end Ics, through filter resistance R13 and sampling resistor R5, flow to the earth again; The second biasing resistor R6 introduces power supply from the output of power module 110, electric current through the second biasing resistor R6 flow through pulse width modulating chip U1 voltage sample end Ics, through filter resistance R13 and sampling resistor R5, flow to the earth again; The electric current of the switch module 140 of flowing through of exporting from power module 110 outputs also flows to the earth through sampling resistor R5.The resistance of filter resistance R13 is generally in 1K Ω left and right, only need several milliamperes of zero points and just can make the voltage of filter resistance R13 reach several volts at zero point, so, can adjust the resistance of the first biasing resistor R9 and the second biasing resistor R6 and set by the electric current of filter resistance R13.Guaranteeing under the condition of stable triggering pulse width modulating chip U1 detection threshold value, the required voltage providing of sampling resistor R5 can provide and reduce because of the voltage of filter resistance R13, so the power loss of sampling resistor R5 is corresponding reduction also, improved the conversion efficiency of product.
As shown in Figure 1, voltage changing module 120 also comprises feedback winding T1Bc-d, the first resistance R 10, the first diode D4, the first capacitor C 9 and the second voltage-stabiliser tube ZE1, the voltage of feedback winding T1Bc-d induction output winding T1Ae-f, the different name end T1Bc of feedback winding T1Bc-d is connected with the positive pole of the first diode D4, the negative pole of the first diode D4 is connected with one end of the first resistance R 10, the Same Name of Ends T1Bd ground connection of feedback winding T1Bc-d, the common port of the other end of the first resistance R 10 and one end of the first capacitor C 9 is connected with the power end Vcc of the negative electrode of the second voltage-stabiliser tube ZE1 and pulse width modulating chip U1, the other end of the first capacitor C 9 is connected with the Same Name of Ends T1Bd of feedback winding T1Bc-d, the voltage sample end Ics of pulse width modulating chip U1 is connected the anode of the second voltage-stabiliser tube ZE1 with the common port of the second biasing resistor.The power end Vcc that the voltage of responding in feedback winding T1Bc-d is received pulse width modulating chip U1 after the effect of the first resistance R 10, the first diode D4 and the first capacitor C 9 provides operating voltage for pulse width modulating chip U1.
In circuit, add the second voltage-stabiliser tube ZE1, for the overvoltage protection of initiatively exporting; In circuit, feed back winding T1Bc-d and be proportional to output winding T1Ae-f, when the output voltage of circuit raises, feedback winding T1Bc-d can sense the lifting of output winding T1Ae-f output voltage, so the voltage of feedback winding T1Bc-d different name end T1Bc will raise; The second voltage-stabiliser tube ZE1 negative electrode is connected with the different name end T1Bc of feedback winding T1Bc-d, so the cathode voltage of the second voltage-stabiliser tube ZE1 raises.By the voltage stabilizing parameter of selected rational the second voltage-stabiliser tube ZE1, can guarantee when certain voltage, to puncture the second voltage-stabiliser tube ZE1, electric current flows to the anode of the second voltage-stabiliser tube ZE1 from the negative electrode of the second voltage-stabiliser tube ZE1, and resistance and sampling resistor R5 ground connection after filtering, after the second voltage-stabiliser tube ZE1 is breakdown, can keep voltage constant, the electric current lifting of coming from the second voltage-stabiliser tube ZE1 the voltage of filter resistance and sampling resistor R5, the current potential of the voltage sample end Ics of pulse width modulating chip U1 rises, the signal that pulse width modulating chip U1 obtains voltage sample end Ics sampling and the voltage of frequency compensation end COMP are inputted respectively inner comparator 220 and are compared, and comparative result is inputted to inner PWM latch 230, output pwm signal is also exported by the output Output of pulse width modulating chip U1, finally impel the output Output of pulse width modulating chip U1 to close Voltage-output, thereby turn-off the voltage input of the input winding T1Aa-b of transformer, transformer has lost the energy input on former limit, thereby the further rising that has naturally just suppressed output voltage reaches the object of protection late-class circuit.Wherein, error amplifier 210 one end are connected with the pressure feedback port FB of pulse width modulating chip U1, and the pressure feedback port FB ground connection of pulse width modulating chip U1.
As shown in Figure 1, therein in an embodiment, direct current rectification filtering module 130 comprises the second diode D1 and the second filter capacitor C11, the positive pole of the second diode D1 is connected with the different name end T1Ae of output winding T1Ae-f, the negative pole of the second diode D1 is the output of direct current rectification filtering module 130, second filter capacitor C11 one end is connected with the negative pole of the second diode D1, the second filter capacitor C11 other end ground connection.Through 130 rectifications of direct current rectification filtering module, filtered electric current, the alternating voltage of positive and negative variation can be become to unidirectional pulsating voltage, the fluctuation conspicuousness of power supply is reduced, meet the electricity consumption requirement of the electrical appliance of electric current steady.
In an embodiment, direct current rectification filtering module 130 also comprises the second resistance R 15, the 3rd filter capacitor C8, the first filter inductance L1, the 4th filter capacitor C12 and the 3rd resistance R D therein; The two ends of the second resistance R 15 are connected with one end of the 3rd filter capacitor C8 with the positive pole of the second diode D1 respectively, and the other end of the 3rd filter capacitor C8 is connected with the negative pole of the second diode D1; The two ends of the first filter inductance L1 are connected with one end of the 4th filter capacitor C12 with the positive pole of the second filter capacitor C11 respectively, and the other end of the 4th filter capacitor C12 is connected with the negative pole of the second filter capacitor C11; The 3rd resistance R D is in parallel with the 4th filter capacitor C12; Further guarantee that the fluctuation that alternating voltage becomes unidirectional pulsating voltage and power supply reduces.
As shown in Figure 1, therein in an embodiment, switch module 140 comprises N-channel MOS FET TR1, the 3rd biasing resistor R12, the second current-limiting resistance R3 and the 5th filter capacitor C10, the drain electrode of N-channel MOS FET TR1 is the input of switch module 140, the source electrode of N-channel MOS FET TR1 is the output of switch module 140, the grid of N-channel MOS FET TR1 is the control end of switch module 140, and the grid of N-channel MOS FET TR1 is connected with the output Output of pulse width modulating chip U1 by the second current-limiting resistance R3, the 3rd biasing resistor R12 is connected between the grid and source electrode of N-channel MOS FET, the two ends of the 5th filter capacitor C10 are connected with source electrode with the drain electrode of N-channel MOS FET TR1 respectively.The output Output output pwm signal of pulse width modulating chip U1 is controlled the turn-on and turn-off of N-channel MOS FET TR1, thus the on off operating mode of control transformer.
Therein in an embodiment, control module 160 comprises filter unit 162, filter unit 162 comprises filter resistance R13 and the 6th filter capacitor C5, the output of the two ends difference connecting valve module 140 of filter resistance R13 and the voltage sample end Ics of pulse width modulating chip U1; One end of the 6th filter capacitor C5 connects the voltage sample end Ics of pulse width modulating chip U1, other end ground connection.
As shown in Figure 1, power module 110 comprises the 7th filter capacitor C0, the 8th filter capacitor C1, the second filter inductance L0, the 3rd diode D3, the 4th diode D5, the 4th resistance R 2, the 5th resistance R 1 and triode Q1.The 7th filter capacitor C0 one end is connected with voltage input end, other end ground connection; The second filter inductance L0 input is connected with voltage input end, and output is connected with the 8th filter capacitor C1 one end, the 8th filter capacitor C1 other end ground connection; The 3rd diode D3, the 4th diode D5 and the 4th resistance R 2 are connected in series, and are connected in parallel with the 8th filter capacitor C1, and the positive pole of the 3rd diode D3 is connected with the 8th filter capacitor C1 one end, and the 4th resistance R 2 one end are connected with the 8th filter capacitor C1 other end; The 5th resistance R 1 one end is connected with the positive pole of the 3rd diode D3, the other end is connected with the emitter of triode Q1, the base stage of triode Q1 is connected with the negative pole of the 4th diode D5, and the collector electrode of triode Q1 is connected with the negative electrode of the second voltage-stabiliser tube ZE1 and the power end Vcc of pulse width modulating chip U1.Can carry out rectifying and wave-filtering to input voltage, and triode Q1 can control whether conducting of triode Q1 according to the height of input voltage, thereby control pulse width modulating chip U1 power end Vcc, whether connect with power module 110.
The above embodiment has only expressed embodiment of the present utility model, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to the utility model the scope of the claims.It should be pointed out that for the person of ordinary skill of the art, without departing from the concept of the premise utility, can also make some distortion and improvement, these all belong to protection range of the present utility model.
Claims (10)
1. a flyback supercharging protective circuit, comprise power module, voltage changing module, direct current rectification filtering module, switch module, control module and feedback module, described voltage changing module comprises input winding and output winding, and described input winding interacts with output winding; The Same Name of Ends of described input winding is connected with the output of described power module, the different name end of described input winding is connected with the input of described switch module, the input of described control module is connected with the output of described switch module, the output of described control module is connected with the control end of switch module, and the output head grounding of described switch module; The different name end of described output winding is connected with described direct current rectification filtering module, the Same Name of Ends ground connection of described output winding; The input of described feedback module connects described direct current rectification filtering module, and the output of described feedback module is connected with described control module; It is characterized in that, described control module comprises pulse width modulating chip, sampling resistor, timing resistor and timing capacitor, the voltage sample end of described pulse width modulating chip and the output of described switch module are all connected one end of described sampling resistor, the other end ground connection of described sampling resistor; Described timing resistor and timing capacitor are connected in series, the timing end of described pulse width modulating chip is connected with the common port of described timing resistor and timing capacitor, the other end of described timing resistor is connected with the reference voltage terminal of described pulse width modulating chip, the other end ground connection of described timing capacitor, the earth terminal ground connection of described pulse width modulating chip; The output of described pulse width modulating chip is connected with the control end of described switch module, and the power end of described pulse width modulating chip is connected with the output of described power module; Described feedback module comprises the first voltage-stabiliser tube and optocoupler loop, described the first voltage-stabiliser tube is connected with described optocoupler loop, the one end in the negative electrode of described the first voltage-stabiliser tube and described optocoupler loop is all connected with the output of described direct current rectification filtering module, the anode of described the first voltage-stabiliser tube links with the other end in described optocoupler loop, and described optocoupler loop ground connection.
2. flyback supercharging protective circuit according to claim 1, is characterized in that, described optocoupler loop comprises optocoupler, control chip, the first current-limiting resistance, the first divider resistance and the second divider resistance; Described optocoupler comprises reflector and receiver, the input of described reflector is connected with described first current-limiting resistance one end, the anodic bonding of the other end of described the first current-limiting resistance and described the first voltage-stabiliser tube, the negative electrode of described the first voltage-stabiliser tube is connected with the output of described direct current rectification filtering module, and the output of described reflector is connected with the input of described control chip; The input of described receiver is connected with the frequency compensation end of described pulse width modulating chip, the output head grounding of described receiver; Described the first divider resistance and the second divider resistance are connected in series, the control end of described control chip is connected with the common port of the second divider resistance with described the first divider resistance, the other end of described the first divider resistance is connected with the output of described direct current rectification filtering module, the other end ground connection of described the second divider resistance, the output head grounding of described control chip; Described control chip is in VD conducting during higher than its voltage threshold.
3. flyback supercharging protective circuit according to claim 2, is characterized in that, described optocoupler loop also comprises building-out capacitor and the first filter capacitor; The two ends of described building-out capacitor are connected with control end with the input of described control chip respectively, and described the first filter capacitor and described the second divider resistance are connected in parallel.
4. flyback supercharging protective circuit according to claim 1, is characterized in that, also comprises the first biasing resistor and the second biasing resistor, and the two ends of described the first biasing resistor connect respectively reference voltage terminal and the voltage sample end of described pulse width modulating chip; The two ends of described the second biasing resistor connect respectively the output of described power module and the voltage sample end of described pulse width modulating chip.
5. flyback supercharging protective circuit according to claim 4, it is characterized in that, described voltage changing module also comprises feedback winding, the first resistance, the first diode, the first electric capacity and the second voltage-stabiliser tube, described feedback winding is responded to the voltage of described output winding, the different name end of described feedback winding is connected with the positive pole of described the first diode, the negative pole of described the first diode is connected with one end of described the first resistance, the Same Name of Ends ground connection of described feedback winding, the common port of the other end of described the first resistance and one end of described the first electric capacity is connected with the negative electrode of described the second voltage-stabiliser tube and the power end of described pulse width modulating chip, the other end of described the first electric capacity is connected with the Same Name of Ends of described feedback winding, the voltage sample end of described pulse width modulating chip is connected the anode of described the second voltage-stabiliser tube with the common port of described the second biasing resistor.
6. flyback supercharging protective circuit according to claim 1; it is characterized in that; described direct current rectification filtering module comprises the second diode and the second filter capacitor; the positive pole of described the second diode is connected with the different name end of described output winding; the negative pole of described the second diode is the output of described direct current rectification filtering module; described second filter capacitor one end is connected with the negative pole of described the second diode, described the second filter capacitor other end ground connection.
7. flyback supercharging protective circuit according to claim 6, is characterized in that, described direct current rectification filtering module also comprises the second resistance, the 3rd filter capacitor, the first filter inductance, the 4th filter capacitor and the 3rd resistance; The two ends of described the second resistance are connected with one end of described the 3rd filter capacitor with the positive pole of described the second diode respectively, and the other end of described the 3rd filter capacitor is connected with the negative pole of described the second diode; The two ends of described the first filter inductance are connected with one end of described the 4th filter capacitor with the positive pole of described the second filter capacitor respectively, and the other end of described the 4th filter capacitor is connected with the negative pole of described the second filter capacitor; Described the 3rd resistance is in parallel with described the 4th filter capacitor.
8. flyback supercharging protective circuit according to claim 1, it is characterized in that, described switch module comprises N-channel MOS FET, the 3rd biasing resistor, the second current-limiting resistance and the 5th filter capacitor, the drain electrode of described N-channel MOS FET is the input of described switch module, the source electrode of described N-channel MOS FET is the output of described switch module, the grid of described N-channel MOS FET is the control end of described switch module, and the grid of described N-channel MOS FET is connected with the output of described pulse width modulating chip by described the second current-limiting resistance, described the 3rd biasing resistor is connected between the grid and source electrode of described N-channel MOS FET, the two ends of described the 5th filter capacitor are connected with source electrode with the drain electrode of described N-channel MOS FET respectively.
9. flyback supercharging protective circuit according to claim 1, it is characterized in that, described control module comprises filter unit, described filter unit comprises filter resistance and the 6th filter capacitor, and the two ends of described filter resistance connect respectively the output of described switch module and the voltage sample end of described pulse width modulating chip; One end of described the 6th filter capacitor connects the voltage sample end of described pulse width modulating chip, other end ground connection.
10. flyback supercharging protective circuit according to claim 5, it is characterized in that, described power module comprises the 7th filter capacitor, the 8th filter capacitor, the second filter inductance, the 3rd diode, the 4th diode, the 4th resistance, the 5th resistance and triode; Described the 7th filter capacitor one end is connected with voltage input end, other end ground connection; Described the second filter inductance input is connected with voltage input end, and output is connected with described the 8th filter capacitor one end, described the 8th filter capacitor other end ground connection; Described the 3rd diode, the 4th diode and the 4th resistance are connected in series, and be connected in parallel with described the 8th filter capacitor, the positive pole of described the 3rd diode is connected with described the 8th filter capacitor one end, and described the 4th resistance one end is connected with described the 8th filter capacitor other end; Described the 5th resistance one end is connected with the positive pole of described the 3rd diode, the other end is connected with the emitter of described triode, the base stage of described triode is connected with the negative pole of described the 4th diode, and the collector electrode of described triode is connected with the negative electrode of described the second voltage-stabiliser tube and the power end of described pulse width modulating chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320541902.7U CN203590041U (en) | 2013-09-02 | 2013-09-02 | Flyback step-up protection circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320541902.7U CN203590041U (en) | 2013-09-02 | 2013-09-02 | Flyback step-up protection circuit |
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| CN203590041U true CN203590041U (en) | 2014-05-07 |
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| CN201320541902.7U Expired - Fee Related CN203590041U (en) | 2013-09-02 | 2013-09-02 | Flyback step-up protection circuit |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106253719A (en) * | 2016-08-06 | 2016-12-21 | 刘超 | A kind of load power source control circuit and device |
| DE102016110846A1 (en) * | 2016-06-14 | 2017-12-14 | Endress + Hauser Gmbh + Co. Kg | Switching Power Supply |
-
2013
- 2013-09-02 CN CN201320541902.7U patent/CN203590041U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102016110846A1 (en) * | 2016-06-14 | 2017-12-14 | Endress + Hauser Gmbh + Co. Kg | Switching Power Supply |
| US10594222B2 (en) | 2016-06-14 | 2020-03-17 | Endress+Hauser SE+Co. KG | Switching power supply |
| CN106253719A (en) * | 2016-08-06 | 2016-12-21 | 刘超 | A kind of load power source control circuit and device |
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