Summary of the invention
The present invention overcomes the defective that exists in the above-mentioned prior art, a kind of current reference generation circuit has been proposed, this current reference generation circuit can produce the primary current reference signal of the high power factor constant current Switching Power Supply main circuit that is applicable to controllable silicon light modulation control, and realizes output constant current control.
The technical scheme that technical solution problem of the present invention is taked is:
The primary current benchmark generation circuit of high power factor constant current Switching Power Supply comprises angle of flow testing circuit, first multiplier, second multiplier and electric current loop.An input of first multiplier is as an input of primary current benchmark generation circuit, the input of angle of flow testing circuit is as another input of primary current benchmark generation circuit, output is connected with another input of first multiplier, the output of first multiplier is as an input of electric current loop, another input of electric current loop is as another input of primary current benchmark generation circuit, the output of electric current loop is connected with an input of second multiplier, another input of second multiplier is connected with the input of angle of flow testing circuit, and the output of second multiplier is as the output of primary current benchmark generation circuit.
A kind of way of realization of electric current loop comprises input resistance, operational amplifier and compensating network, one end of input resistance is as an input of electric current loop, the negative input of another termination operational amplifier, defeated another input of the forward of operational amplifier as electric current loop, the output of operational amplifier is as the output of electric current loop, one end of compensating network is connected with the negative input of operational amplifier, and the other end of compensating network is connected with the output of operational amplifier.
The another kind of way of realization of described electric current loop comprises input resistance, operational amplifier and compensating network, one end of input resistance is as an input of electric current loop, the negative input of another termination operational amplifier, defeated another input of the forward of operational amplifier as electric current loop, the output of operational amplifier is as the output of electric current loop, one end of compensating network is connected with the output of operational amplifier, the other end ground connection of compensating network.
Further say, described primary current benchmark generation circuit also comprises first filter and second filter, the input of first filter is as the input of primary current benchmark generation circuit, the output of first filter is connected with an input of first multiplier, the input of second filter is as the input of primary current benchmark generation circuit, and the output of second filter is connected with an input of electric current loop.
Further say, described primary current benchmark generation circuit also comprises the 3rd filter and the 3rd multiplier, the input of the 3rd filter is as primary current benchmark generation circuit input end, the output of the 3rd filter is connected with an input of the 3rd multiplier, another input of the 3rd multiplier is as another input of primary current benchmark generation circuit, and the output of the 3rd multiplier is connected with the input of second filter.
The implementation method of primary current benchmark generation circuit comprises the steps:
(1) mean value of the primary current of acquisition Switching Power Supply main circuit
(2) the switching tube driving pulse ON time signal Ton of acquisition reflection Switching Power Supply main circuit;
(3) the output diode ON time signal Toff1 of acquisition reflection Switching Power Supply main circuit;
(4) signal alpha of the thyristor operating angle of acquisition reflection Switching Power Supply main circuit;
(5) make by control
Mean value be steady state value K, and obtain
With
Error amplification signal Verror between the mean value;
(6) the commutating voltage waveform signal Iac of the rectifier bridge output of acquisition Switching Power Supply main circuit;
(7) the voltage waveform signal Iac of error amplification signal Verror that step (5) is obtained and step (6) acquisition multiplies each other, and produces primary current benchmark Iref.
When the Switching Power Supply main circuit is operated in electric current continuously or during the critical flow Discontinuous Conduction mode, above-mentioned steps can further be reduced to:
(1) mean value of the primary current of acquisition Switching Power Supply main circuit
(2) the switching tube driving pulse duty cycle signals D of acquisition Switching Power Supply main circuit;
(3) signal alpha of the thyristor operating angle of acquisition reflection Switching Power Supply main circuit;
(4) make by control
Mean value be steady state value K, and obtain
With
Error amplification signal Verror between the mean value;
(5) the commutating voltage waveform signal Iac of the rectifier bridge output of acquisition Switching Power Supply main circuit;
(6) the voltage waveform signal Iac of error amplification signal Verror that step (4) is obtained and step (5) acquisition multiplies each other, and produces primary current benchmark Iref.
Beneficial effect of the present invention: the current reference generation circuit that the present invention proposes only need detect the primary current signal and can realize producing close-loop feedback control to the output current constant current former limit simultaneously and realize the required current reference of High Power Factor control; The present invention is that mean value by the primary current signal obtains to the constant current of output current control, keep and need not sampling, eliminated the error that the sampling maintenance brings, improved the constant current accuracy of output current, and not only be applicable to continuous current mode but also be applicable to the discontinuous current pattern, and can realize phase-controlled dimming control.
Embodiment
Be elaborated below in conjunction with block diagram of the present invention and specific embodiment schematic diagram content of the present invention.
As shown in Figure 6A, primary current benchmark generation circuit of the present invention comprises:
Angle of flow testing circuit 105: angle of flow testing circuit receives the output waveform signals Vac from the rectifier bridge of Switching Power Supply main circuit, the output reflection controllable silicon dimmer angle of flow and the fixing pulse signal of amplitude;
First multiplier 106: described first multiplier 106 receives from the drive signal Vg of the switching tube of Switching Power Supply main circuit and the output signal of angle of flow testing circuit 105, exports the product of the two;
Electric current loop 107: described electric current loop 107 comprises operational amplifier Uf, input resistance R1, compensating network C1; Wherein input resistance R1 one termination is received the primary current signal ipri from the Switching Power Supply main circuit, the negative terminal input of resistance R 1 another termination operational amplifier, the anode input of operational amplifier Uf connects the output of second multiplier 106, and operational amplifier Uf is output as the output of electric current loop 107; Described electric current loop 107 has the average value filtering function, therefore at the input of operational amplifier Uf, the mean value of primary current signal ipri and the output signal of second multiplier 106 compare, the error signal of the two output after operational amplifier Uf and compensating network C1 amplification.
Introduced two filters at the primary current benchmark generation circuit shown in the relative Fig. 6 A of primary current benchmark generation circuit shown in Fig. 6 B, wherein:
First filter 104: described first filter receives the drive signal Vg from the switching tube of Switching Power Supply main circuit, its high-frequency harmonic component of filtering, an input of output termination first multiplier of first filter;
Second filter 101: the primary current signal ipri that described second filter 101 receives from the Switching Power Supply main circuit, its harmonic component of filtering, the mean value of output ipri, the end of the input resistance R1 of the output termination electric current loop 107 of second filter 101;
Primary current benchmark generation other part of module of circuit shown in Fig. 6 B and annexation are identical with the primary current benchmark generation circuit shown in Fig. 6 A.
The primary current benchmark generation circuit shown in relative Fig. 6 B has been introduced the 3rd filter 103 and the 3rd multiplier 102 in the primary current benchmark generation circuit shown in Fig. 6 C, wherein, the control signal Vtoff1 of an input termination reflection secondary diode current flow time of the 3rd filter 103, an input of output termination the 3rd multiplier 102 of the 3rd filter 103, the average value signal of the primary current signal ipri of another input termination second filter 101 outputs of the 3rd multiplier 102, the product of the two is delivered to an input of electric current loop 107; Primary current benchmark generation other part of module of circuit shown in Fig. 6 C and annexation are identical with the primary current benchmark generation circuit shown in Fig. 6 B.
Further, the position of the 3rd filter 103 in the primary current benchmark generation circuit shown in Fig. 6 C can change, shown in Fig. 6 D, the input of change back the 3rd filter 103 connects the output of the 3rd multiplier 102, the output of the 3rd filter 103 connects an input of electric current loop 107, the control signal Vtoff1 of one of the 3rd multiplier input termination reflection secondary diode current flow time, his part of module and annexation are identical with the primary current benchmark generation circuit shown in Fig. 6 C.
Described first multiplier 106 and the 3rd multiplier 102 are multiplier or the equivalent electric circuit module that realizes equivalent function.
Described control signal Vtoff1 is from the auxiliary winding of switching mode power supply transformer or the gate pole control signal of Switching Power Supply.
Identical or the approximately equal of output diode ON time of the positive pulse width of described control signal Vtoff1 and Switching Power Supply main circuit.
The compensating network of described electric current loop 107 is known technologies such as proportional integral link that electric capacity, resistance and electric capacity constitute;
The operational amplifier of described electric current loop 107 is current mode operational amplifiers, and compensating network is connected between the output and ground of operational amplifier Uc.
The operational amplifier of described electric current loop 107 is voltage-type operational amplifiers, and compensating network is connected between the output and negative input end of operational amplifier Uc.
Former limit switching tube electric current and secondary diode current waveform were respectively as shown in Figure 7 and Figure 8 when Switching Power Supply was operated in continuous current mode and discontinuous current pattern; The expression formula that can derive output current Io under above-mentioned two kinds of mode of operations according to waveform is all:
(1)
Wherein,
Be the mean value of secondary diode current,
Be the mean value of former limit switching tube electric current, Np is the former limit of the transformer number of turn, and Ns is the transformer secondary number of turn, and Ton is a former limit switching tube ON time,
Be the cycle mean value of former limit switching tube ON time, Toff1 is the secondary diode continuousing flow time,
Be the cycle mean value of secondary diode continuousing flow time.
The principle of the primary current benchmark of the present invention shown in Fig. 6 C is: gather primary current ipri earlier, obtain the mean value of primary current after 101 filtering of second filter
, the mean value of Vtoff1 after the 3rd filter 103 with the control signal that reflects secondary diode continuousing flow time T off1 multiplies each other then, obtains
, obtain the Ton signal by former limit switching drive signal Vg, after first filter, 104 filtering high fdrequency components, obtain the mean value of Ton signal
Send into electric current loop after multiplying each other with the D. C. value of setting, know as long as two input end signals of Control current ring operational amplifier equate can realize exporting constant current that by formula (1) the output waveform signals Vac of the rectifier bridge of the output signal of operational amplifier and Switching Power Supply main circuit output waveform after the 3rd multiplier 108 multiplies each other is that the reference signal Iref of the primary current of half-sinusoid controls to realize PFC; When need carried out phase-controlled dimming, controllable silicon dimmer angle of flow signal was through the pulse signal of the angle of flow testing circuit 105 output reflection angles of flow, with the mean value of Ton signal
Benchmark is sent into electric current loop after multiplying each other, and can realize the output current brightness adjustment control.
Because
Be approximately a direct current level, as can be known
, so Fig. 6 C circuit can be deformed into the primary current reference circuit of the present invention shown in Fig. 6 D, principle is: gather primary current ipri earlier, obtain the mean value of primary current after 101 filtering of second filter
, the control signal Vtoff1 with reflection secondary diode continuousing flow time T off1 multiplies each other then, obtains after 103 filtering of the 3rd filter
, obtain the Ton signal by former limit switching drive signal Vg, after first filter, 104 filtering high fdrequency components, obtain the mean value of Ton signal
Send into electric current loop after multiplying each other with the D. C. value of setting, know as long as two input end signals of Control current ring operational amplifier equate can realize exporting constant current that by formula (1) the output waveform signals Vac of the rectifier bridge of the output signal of operational amplifier and Switching Power Supply main circuit output waveform after the 3rd multiplier 108 multiplies each other is that the reference signal Iref of the primary current of half-sinusoid controls to realize PFC; When need carried out phase-controlled dimming, controllable silicon dimmer angle of flow signal was through the pulse signal of the angle of flow testing circuit 105 output reflection angles of flow, with the mean value of Ton signal
Benchmark is sent into electric current loop after multiplying each other, and can realize the output current brightness adjustment control.
When the Switching Power Supply main circuit is operated in continuous current mode or critical flow Discontinuous Conduction mode, because Ton+Toff1=Ts, wherein Ts is the switch periods of former limit switching tube, can release (2) formula relation by (1) formula.
(2)
According to (2) formula, primary current benchmark generation circuit of the present invention can be simplified shown in Fig. 6 B.Compare with invention circuit block diagram shown in Fig. 6 D with Fig. 6 C, the module relevant second multiplier 102 and the 3rd filter 103 have been saved among Fig. 6 B with Toff1, the primary current signal ipri of Switching Power Supply main circuit directly sends into electric current loop after second filter 101 is average, other module and annexation are all identical with circuit block diagram shown in Fig. 6 C.
Further, because electric current loop 107 has filter function, first filter 104 and second filter 101 among Fig. 6 B can further dispense, as shown in Figure 6A, the primary current signal ipri of Switching Power Supply main circuit directly sends into electric current loop, and other module and annexation are constant.
Based on primary current benchmark generation circuit of the present invention shown in Figure 6, high power factor constant current switching power source control circuit first specific embodiment of former limit control as shown in Figure 9, it is continuous that this control circuit is fit to electric current, interrupted and critical flow Discontinuous Conduction mode, comprise current reference generation circuit 1001, output diode ON time detection module 200, comparator 300, switching tube conducting control module 400 and rest-set flip-flop 500, and the splicing ear of control circuit and main circuit comprises primary current sampling end Isen, output diode ON time test side Idet, rectifier bridge voltage waveform signal test side Iac and drive end Drv; Wherein, described current reference generation circuit 1001 adopts structure shown in Fig. 6 C; Output diode ON time detection module is through the ON time of output diode ON time test side sense switch electric power main circuit diode, and Vtoff1 is to current reference generation circuit for the output control signal; The primary current sampled signal is received the positive input terminal of comparator 300 and the Ipri end of current reference generation circuit through primary current sampling end Isen, the half-sinusoid signal Iref of the negative input end input current benchmark generation circuit output of comparator 300, the output waveform signals of the rectifier bridge of led driver main circuit is received the Vac end of current reference generation circuit 1001 through rectifier bridge voltage waveform signal test side Iac, the input R of rest-set flip-flop 500 connects the output of comparator 300, the output of the input S termination switching tube conducting control module 400 of rest-set flip-flop 500, the output signal of rest-set flip-flop 500 is picked gate pole to former limit switch through drive end Drv; Current reference generation circuit 1001 produces half-sinusoid signal Iref, when the primary current sampled signal rises to when touching half-sinusoid signal Iref, the output signal of comparator 300 is high level from the low level upset, after this drop to when being lower than half-sinusoid signal Iref when the primary current sampled signal, comparator 300 output signals are low level from the high level upset; When the rising edge saltus step from the low level to the high level of 300 to one of the reset terminal R of rest-set flip-flop 500 end detection comparators, the output signal of rest-set flip-flop 500 is reset to low level from high level, the shutoff of the switching tube of control switching main circuit, when the set end S of rest-set flip-flop 500 end detects the rising edge saltus step from the low level to the high level of 400 1 of switching tube conducting control modules, the output signal of rest-set flip-flop 500 is a high level from low level set, and the generation pulse signal so goes round and begins again.
High power factor constant current switching power source control circuit second specific embodiment of former limit control of the present invention as shown in figure 10, this control circuit is fit to the continuous and critical flow Discontinuous Conduction mode of electric current, comprise current reference generation circuit 1002, comparator 300, switching tube conducting control module 400 and rest-set flip-flop 500, and the splicing ear of control circuit and main circuit comprises primary current sampling end Isen, rectifier bridge voltage waveform signal test side Iac and drive end Drv; Wherein, described current reference generation circuit adopts structure shown in Fig. 6 B; The primary current sampled signal is received the positive input terminal of comparator 300 and the Ipri end of current reference generation circuit through primary current sampling end Isen, the half-sinusoid signal Iref of the negative input end input current benchmark generation circuit output of comparator 300, the output waveform signals of the rectifier bridge of led driver main circuit is received the Vac end of current reference generation circuit 1002 through rectifier bridge voltage waveform signal test side Iac, the input R of rest-set flip-flop 500 connects the output of comparator 300, the output of the input S termination switching tube conducting control module 400 of rest-set flip-flop 500, the output signal of rest-set flip-flop 500 is picked gate pole to former limit switch through drive end Drv; Current reference generation circuit 1002 produces half-sinusoid signal Iref, when the primary current sampled signal rises to when touching half-sinusoid signal Iref, the output signal of comparator 300 is high level from the low level upset, after this drop to when being lower than half-sinusoid signal Iref when the primary current sampled signal, comparator 300 output signals are low level from the high level upset; When the rising edge saltus step from the low level to the high level of 300 to one of the reset terminal R of rest-set flip-flop 500 end detection comparators, the output signal of rest-set flip-flop 500 is reset to low level from high level, the shutoff of the switching tube of control switching main circuit, when the set end S of rest-set flip-flop 500 end detects the rising edge saltus step from the low level to the high level of 400 1 of switching tube conducting control modules, the output signal of rest-set flip-flop 500 is a high level from low level set, and the generation pulse signal so goes round and begins again.
High power factor constant current switching power source control circuit the 3rd specific embodiment of former limit control of the present invention as shown in figure 11, this control circuit is fit to continuous, the interrupted and critical flow Discontinuous Conduction mode of electric current, comprise current reference generation circuit 1001, output diode ON time detection module 200, electric current loop 301, comparator 302 and sawtooth waveforms generation module 303, and the splicing ear of control circuit and main circuit comprises primary current sampling end Isen, output diode ON time test side Idet, rectifier bridge voltage waveform signal test side Iac and drive end Drv; Wherein, described current reference generation circuit 1001 adopts structure shown in Fig. 6 C; Output diode ON time detection module is through the ON time of output diode ON time test side inspection Idet slowdown monitoring switch electric power main circuit diode, and Vtoff1 is to current reference generation circuit for the output control signal; The primary current sampled signal is received the Ipri end of current reference generation circuit 1001 through primary current sampling end Isen, the output signal of the filter 101 in the current reference generation circuit 1001 is received the negative input end of the operational amplifier Uf2 of electric current loop 301 through resistance R 3, the half-sinusoid signal Iref of the positive input terminal input current benchmark generation circuit output of the operational amplifier Uf2 of electric current loop 301, the output waveform signals of the rectifier bridge of led driver main circuit is received the Vac end of current reference generation circuit 1001 through rectifier bridge voltage waveform signal test side Iac, the output of the operational amplifier Uf2 of electric current loop 301 connects R2 and the compensating network of C2 serial connection formation and the positive input terminal of comparator 302, the other end ground connection of compensating network, the output signal of the negative input end input sawtooth waveforms generation module 303 of comparator 302; The mean value of 301 pairs of primary current sampled signals of electric current loop and current reference generation circuit I ref compare, the error of the two is amplified output through electric current loop 301, the sawtooth signal that the error amplification signal of 302 pairs of electric current loops of comparator, 301 outputs and sawtooth waveforms generation module 303 produce compares, the sawtooth waveforms amplitude that is higher than the sawtooth signal generation of sawtooth waveforms generation module 303 generations when the error amplification signal amplitude of electric current loop 301 outputs, comparator 302 output high level, when the error amplification signal amplitude of electric current loop 301 output is lower than the sawtooth waveforms amplitude that sawtooth signal that sawtooth waveforms generation module 303 produces produces, comparator 302 output low levels.
High power factor constant current switching power source control circuit the 4th specific embodiment of former limit control of the present invention as shown in figure 12, this control circuit is fit to the continuous and critical flow Discontinuous Conduction mode of electric current, comprise current reference generation circuit 1002, electric current loop 301, comparator 302 and sawtooth waveforms generation module 303, and the splicing ear of control circuit and main circuit comprises primary current sampling end Isen, rectifier bridge voltage waveform signal test side Iac and drive end Drv; Wherein, described current reference generation circuit 1002 adopts structure shown in Fig. 6 B; The primary current sampled signal is received the Ipri end of current reference generation circuit 1002 through primary current sampling end Isen, the output signal of the filter 101 in the current reference generation circuit 1002 is received the negative input end of the operational amplifier Uf2 of electric current loop 301 through resistance R 3, the half-sinusoid signal Iref of the positive input terminal input current benchmark generation circuit output of the operational amplifier Uf2 of electric current loop 301, the output waveform signals of the rectifier bridge of led driver main circuit is received the Vac end of current reference generation circuit 1002 through rectifier bridge voltage waveform signal test side Iac, the output of the operational amplifier Uf2 of electric current loop 301 connects R2 and the compensating network of C2 serial connection formation and the positive input terminal of comparator 302, the other end ground connection of compensating network, the output signal of the negative input end input sawtooth waveforms generation module 303 of comparator 302; The mean value of 301 pairs of primary current sampled signals of electric current loop and current reference generation circuit I ref compare, the error of the two is amplified output through electric current loop 301, the sawtooth signal that the error amplification signal of 302 pairs of electric current loops of comparator, 301 outputs and sawtooth waveforms generation module 303 produce compares, the sawtooth waveforms amplitude that is higher than the sawtooth signal generation of sawtooth waveforms generation module 303 generations when the error amplification signal amplitude of electric current loop 301 outputs, comparator 302 output high level, when the error amplification signal amplitude of electric current loop 301 output is lower than the sawtooth waveforms amplitude that sawtooth signal that sawtooth waveforms generation module 303 produces produces, comparator 302 output low levels.
Switching tube conducting control module 400 can adopt clocked flip-flop as shown in figure 13, is applicable to decide frequency control, and wherein clocked flip-flop belongs to this professional skill field known technology.
Switching tube conducting control module 400 can adopt circuit as shown in figure 14, be applicable to critical discontinuous mode, wherein zero passage detection 501 inputs embody the signal Idet of secondary diode current flow time, output and the anti-phase zero passage detection signal of Idet, time delay process 502 is used for compensating secondary diode current zero crossing and switching tube the lowest point, the former limit error between opening, open-minded to realize switching tube the lowest point, former limit, zero passage detection 501 can realize with conventional comparator, belong to this professional skill field known technology.
Figure 15 is a specific embodiment of output diode ON time detection module 200, comprises comparator 201, biasing benchmark 202, inverter 203, rest-set flip-flop 204 and XOR gate 205.An input signal Idet of the positive input termination output diode ON time detection module 200 of comparator 201 wherein, the negative input end of comparator 201 connects biasing benchmark 202, the input of the output termination inverter 203 of comparator 201, the output of inverter 203 connects the R end (reset terminal) of rest-set flip-flop 204 and an input of XOR gate 205 respectively, the S end (set end) of rest-set flip-flop 204 meets another input signal Vg of output diode ON time detection module 200, the output Q output Vtoff1 of rest-set flip-flop 204.The key waveforms of output diode ON time detection module 200 embodiment shown in Figure 15 when led driver is operated in discontinuous current as shown in figure 16, the waveform of input Idet when wherein VIdet connects the auxiliary winding different name end of main circuit for input Idet; V201 is the output waveform of comparator 201; V203 is the output waveform signals of inverter 203; Vg is the former limit of a main circuit switching tube gate electrode drive signals; V204 is the output waveform signals of rest-set flip-flop 204; Vtoff1 is the output signal of XOR gate 205.From waveform shown in Figure 16 as can be seen, output diode ON time detection module shown in Figure 15 can detect the interval of the auxiliary winding different name end high level of main circuit, thereby roughly detects main circuit output diode ON time interval.
Figure 17 is the specific embodiment that the high power factor constant current switching power source control circuit of the former limit control that constitutes of Fig. 9 and primary current benchmark generation circuit of the present invention shown in Figure 11 is applied to inverse-excitation type constant current switch power supply, and wherein inverse-excitation type switch power-supply is operated in continuous current mode, discontinuous mode or critical discontinuous mode.Inverse-excitation type switch power-supply comprises: inverse-excitation type main circuit and control circuit, wherein, described main circuit comprises interchange input 10, controllable silicon dimmer 11, rectifier bridge 12, input capacitance 13, rectifier bridge voltage waveform sample circuit 14, transformer 15, former limit switching tube 16, sampling resistor 17, output diode 18 and output capacitance 19; Circuit connecting relation is as follows: exchange input 10 connects rectifier bridge 12 through controllable silicon dimmer 11 two inputs, one end of the positive output termination input capacitance 13 of rectifier bridge 12, the end of the same name of one end of rectifier bridge voltage waveform sample circuit 14 and transformer 15 former limit windings, the negative output terminal ground connection of rectifier bridge 12, the other end ground connection of input capacitance 12, the rectifier bridge voltage waveform signal test side Idet of the other end connection control circuit of rectifier bridge voltage waveform sample circuit 14, the drain electrode of the former limit of the different name termination switching tube 16 of the former limit winding of transformer 15, the source electrode of former limit switching tube 16 meets an end of sampling resistor 17 and the primary current sampling end Isen of control circuit, the other end ground connection of sampling resistor 16, the drive end Drv of the gate pole connection control circuit of former limit switching tube 16, the anode of the different name termination output diode 18 of the secondary winding of transformer 15, the negative electrode of output diode 18 connects the positive pole of output capacitance 19, the end of the same name of the secondary winding of transformer 15 links to each other with the negative pole of output capacitance 19, the end ground connection of the same name of the auxiliary winding of transformer 15, the output diode ON time test side Idet of the different name termination control circuit of the auxiliary winding of transformer 15.
Figure 18 is the specific embodiment that the high power factor constant current switching power source control circuit of the former limit control that constitutes of Figure 10 and primary current benchmark generation circuit of the present invention shown in Figure 12 is applied to inverse-excitation type constant current switch power supply, and wherein inverse-excitation type switch power-supply is operated in discontinuous mode or critical discontinuous mode.Inverse-excitation type switch power-supply comprises: inverse-excitation type main circuit and control circuit, wherein, described main circuit comprises interchange input 10, controllable silicon dimmer 11, rectifier bridge 12, input capacitance 13, rectifier bridge voltage waveform sample circuit 14, transformer 15, former limit switching tube 16, sampling resistor 17, output diode 18 and output capacitance 19; Circuit connecting relation is as follows: exchange input 10 connects rectifier bridge 12 through controllable silicon dimmer 11 two inputs, one end of the positive output termination input capacitance 13 of rectifier bridge 12, the end of the same name of one end of rectifier bridge voltage waveform sample circuit 14 and transformer 15 former limit windings, the negative output terminal ground connection of rectifier bridge 12, the other end ground connection of input capacitance 12, the rectifier bridge voltage waveform signal test side Idet of the other end connection control circuit of rectifier bridge voltage waveform sample circuit 14, the drain electrode of the former limit of the different name termination switching tube 16 of the former limit winding of transformer 15, the source electrode of former limit switching tube 16 meets an end of sampling resistor 17 and the primary current sampling end Isen of control circuit, the other end ground connection of sampling resistor 16, the drive end Drv of the gate pole connection control circuit of former limit switching tube 16, the anode of the different name termination output diode 18 of the secondary winding of transformer 15, the negative electrode of output diode 18 connects the positive pole of output capacitance 19, and the end of the same name of the secondary winding of transformer 15 links to each other with the negative pole of output capacitance 19.
The concrete module that the present invention includes, those skilled in the art can have numerous embodiments under the prerequisite of its spirit, or by various compound mode, form different specific embodiments, for example multiplication module can realize with switch combination, is not described in detail here.
No matter above how detailed explanation is, can have many modes to implement the present invention in addition, and as numeral control etc., described in the specification is specific embodiment of the present invention.All equivalent transformations that spirit is done according to the present invention or modification all should be encompassed within protection scope of the present invention.
The above-mentioned detailed description of the embodiment of the invention be not exhaustive or be used to limit the present invention to above-mentioned clear and definite in form.Above-mentioned with schematic purpose specific embodiment of the present invention and example are described in, those skilled in the art will recognize that and can carry out various equivalent modifications within the scope of the invention.
At above-mentioned declarative description specific embodiment of the present invention and having described in the anticipated optimal set pattern, no matter how detailed explanation appearred hereinbefore, also can be implemented in numerous ways the present invention.The details of foregoing circuit structure and control mode thereof is carried out in the details at it can carry out considerable variation, yet it still is included among the present invention disclosed herein.
Should be noted that as above-mentioned that employed specific term should not be used to be illustrated in when explanation some feature of the present invention or scheme redefines this term here with restriction of the present invention some certain features, feature or the scheme relevant with this term.In a word, should be with the terminological interpretation in the claims of enclosing, used for not limiting the invention to disclosed specific embodiment in the specification, unless above-mentioned detailed description part defines these terms clearly.Therefore, actual range of the present invention not only comprises the disclosed embodiments, also is included in to implement or carry out all equivalents of the present invention under claims.