CN104143920A - Resonant transformation circuit - Google Patents
Resonant transformation circuit Download PDFInfo
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- CN104143920A CN104143920A CN201310170176.7A CN201310170176A CN104143920A CN 104143920 A CN104143920 A CN 104143920A CN 201310170176 A CN201310170176 A CN 201310170176A CN 104143920 A CN104143920 A CN 104143920A
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Abstract
A resonant transformation circuit is used for converting output voltage of an external power source to be working voltage needed by power receiving equipment. The resonant transformation circuit comprises a voltage conversion circuit, a rectification filter circuit, a first sampling unit, a second sampling unit and a sudden detection circuit. The voltage conversion circuit is used for converting the output voltage of the external power source to be first voltage. The rectification filter circuit carries out rectification filtering on the first voltage and outputs second voltage. The first sampling unit is used for sampling current flowing through the power receiving equipment and outputting first sampling voltage of the sampling current. The second sampling unit outputs second sampling voltage according to the second voltage. The sudden detection circuit outputs a sudden signal according to the first sampling voltage output by the first sampling unit and the second sampling voltage output by the second sampling unit. By means of the resonant transformation circuit, power losses under a light-load or no-load state are reduced, the switchover frequency of a sudden mode is decreased, and the service life of the resonant transformation circuit is prolonged.
Description
Technical field
The present invention relates to resonant transform circuit, relate in particular to a kind of resonant transform circuit with burst mode.
Background technology
Resonant transform circuit has the advantage that conversion efficiency is high, in power supply changeover device, is more and more applied.Current, how to realize when resonant transform circuit output loading is zero load or underloading, reducing no-load power consumption or underloading power consumption is a large research topic.
Summary of the invention
In view of this, need provide a kind of resonant transform circuit, power consumption when it can reduce no-load or underloading.
A kind of resonant transform circuit that embodiment of the present invention provides, for external power source output voltage is converted to the required operating voltage of power receiving equipment, described resonant transform circuit comprises voltage conversion circuit, current rectifying and wave filtering circuit, the first sampling unit, the second sampling unit, burst testing circuit.Described voltage conversion circuit is used for being electrically connected described external power source, for converting the direct voltage of described external power source output to first voltage.Described current rectifying and wave filtering circuit is used for being electrically connected described voltage conversion circuit and described power receiving equipment, for described the first voltage is carried out rectifying and wave-filtering and exports second voltage, so that described power receiving equipment is powered.Described the first sampling unit is used for being electrically connected described power receiving equipment, for the electric current of the described power receiving equipment of flowing through being sampled and exporting the first sampled voltage of sample rate current.Described the second sampling unit is used for being electrically connected described current rectifying and wave filtering circuit, for exporting the second sampled voltage according to the second voltage of described current rectifying and wave filtering circuit output.Described burst testing circuit is used for being electrically connected described voltage conversion circuit, described the first sampling unit and described the second sampling unit, for exporting burst according to the second sampled voltage of the first sampled voltage of described the first sampling unit output and described the second sampling unit output.Wherein said voltage conversion circuit is also for regulating described the first voltage according to described burst.
Preferably, described voltage conversion circuit comprises Pwm controller, switch element, resonant element.Described Pwm controller is used for being electrically connected at described burst testing circuit, for generation of pulse width modulating signal and according to the pulse width modulating signal of the burst regulation output of described burst testing circuit output, to regulate the first voltage of described voltage conversion circuit output.Described switch element is used for being electrically connected at described Pwm controller and described external power source, for the converting direct-current voltage into alternating-current voltage that described external power source is exported.Described resonant element is used for being electrically connected at described switch element and described current rectifying and wave filtering circuit, for converting the alternating voltage of described switch element output to first voltage.
Preferably, described switch element comprises the first field-effect transistor, the second field-effect transistor.Described the first field effect transistor gate is electrically connected at described Pwm controller, and drain electrode is electrically connected at described external power source, and source electrode is electrically connected at described resonant element.Described the second field effect transistor gate is electrically connected at described Pwm controller, and drain electrode is electrically connected at the source electrode of described the first field-effect transistor, source ground.Described resonant element comprises transformer, the first inductance, the first electric capacity.Described transformer comprises primary side, secondary side, described primary side comprises high voltage input terminal, low pressure input, described secondary side comprises the first high-voltage output end, the second high-voltage output end and low-voltage output, and described secondary side is electrically connected at described current rectifying and wave filtering circuit.Described the first inductance is electrically connected between the source electrode of described the first field-effect transistor and the high voltage input terminal of described transformer.Described first electric capacity one end is electrically connected at the low pressure input of described transformer, other end ground connection.
Preferably, described current rectifying and wave filtering circuit comprises rectification unit, filter unit.Described rectification unit is used for being electrically connected between described voltage conversion circuit and described power receiving equipment, for the first voltage of described voltage conversion circuit output is carried out to rectification.Described filter unit is used for being electrically connected between described rectification unit and described power receiving equipment, for the first voltage of described voltage conversion circuit output is carried out to filtering.
Preferably, described rectification unit comprises the first diode, the second diode.Described the first diode cathode is electrically connected at described voltage conversion circuit, and negative pole is electrically connected at described power receiving equipment.Described the second diode cathode is electrically connected at described voltage conversion circuit, and negative pole is electrically connected at the negative pole of described the first diode.Described filter unit is the second electric capacity, and described second electric capacity one end is electrically connected at the common port of described the first diode and the second diode, other end ground connection.
Preferably, described the first sampling unit is the first resistance, and one end is electrically connected at described power receiving equipment and described burst testing circuit, other end ground connection.
Preferably, described the second sampling unit comprises the second resistance, the 3rd resistance.Described second resistance one end is electrically connected at described current rectifying and wave filtering circuit, and the other end is electrically connected at described burst testing circuit.Described the 3rd resistance one end is electrically connected at the other end of described the second resistance, other end ground connection.
When being not less than the second predeterminated voltage, exports the second sampled voltage that preferably, described burst testing circuit is less than the first predeterminated voltage and described the second sampling unit at the first sampled voltage of described the first sampling unit described burst.
Preferably, described voltage conversion circuit judges whether break-off according to the burst of described burst testing circuit output, and when described voltage conversion circuit detects described burst, described voltage conversion circuit is 0 by described the first voltage-regulation.
Preferably, described burst testing circuit comprises the first comparing unit, the first error amplifying unit, the second comparing unit, burst output unit.Described the first comparing unit is for comparing the first reference voltage and described the first sampled voltage and exporting the first comparison signal.Described the first error amplifying unit is for exporting the first error signal according to the second reference voltage and described the second sampled voltage.Described the second comparing unit is for exporting the second comparison signal according to described the first comparison signal and described the first error signal.Described burst output unit is for exporting burst according to the 3rd reference voltage and described the second comparison signal.
Preferably, described the first comparing unit comprises the first comparator, the 4th resistance.Described the first comparator comprises positive input, reverse input end and output, described positive input is used for receiving the first reference voltage, described reverse input end is electrically connected at described the first sampling unit, and described output is electrically connected at described the second comparing unit.Described the 4th resistance one end is electrically connected at the positive input of described the first comparator, and the other end is electrically connected at the output of described the first comparator.
Preferably, described the first error amplifying unit comprises the first amplifier, the 3rd electric capacity.Described the first amplifier comprises positive input, reverse input end and output, described positive input is used for receiving described the second reference voltage, described reverse input end is electrically connected at described the second sampling unit, and described output is electrically connected at described the second comparing unit.Described the 3rd electric capacity one end is electrically connected at the reverse input end of described the first amplifier, and the other end is electrically connected at the output of described the first amplifier.
Preferably, described the second comparing unit comprises the 5th resistance, the first optocoupler transducer.Described the 5th resistance one end is electrically connected at described the first comparing unit.Described the first optocoupler transducer comprises input and output, and described input is electrically connected between the other end and described the first error amplifying unit of described the 5th resistance, and described output is electrically connected between described burst output unit and ground.
Preferably, described burst output unit comprises the 6th resistance, the second comparator.Described the 6th resistance one end is electrically connected at described external power source, and the other end is electrically connected at described the second comparing unit.Described the second comparator comprises positive input, reverse input end and output, described positive input is used for receiving described the 3rd reference voltage, described reverse input end is electrically connected at the common port of described the 6th resistance and described the second comparing unit, and described output is electrically connected at described voltage conversion circuit.
Preferably, described resonant transform circuit also comprises feedback circuit, be used for being electrically connected described the second sampling unit and described voltage conversion circuit, for the second sampled voltage output feedback signal of exporting according to described the second sampling unit, described voltage conversion circuit is also for regulating described the first voltage according to described feedback signal.
Preferably, described feedback circuit is exported described feedback signal when the second sampled voltage of described the second sampling unit output is less than the 3rd predeterminated voltage.
Preferably, described voltage conversion circuit is also for reducing the frequency of the first voltage of output according to described feedback signal.
Preferably, described feedback circuit comprises the second error amplifying unit, feedback signal output unit.Described the second error amplifying unit is for exporting the second error signal according to the second sampled voltage of the 4th reference voltage and described the second sampling unit output.Described feedback signal output unit is used for according to described the second error signal output feedback signal.
Preferably, described the second error amplifying unit comprises the second amplifier, the 4th electric capacity.Described the second amplifier comprises positive input, reverse input end and output, described positive input is used for receiving described the 4th reference voltage, described reverse input end is electrically connected at described the second sampling unit, and described output is electrically connected at described feedback signal output unit.Described the 4th electric capacity one end is electrically connected at the reverse input end of described the second amplifier and the common port of described the second sampling unit, and the other end is electrically connected at the output of described the second amplifier.
Preferably, described feedback signal output unit comprises the 7th resistance, the second optocoupler transducer.Described the 7th resistance one end is electrically connected at described current rectifying and wave filtering circuit.Described the second optocoupler transducer comprises input and output, and described input is electrically connected between the other end and described the second error amplifying unit of described the 7th resistance, and described output is electrically connected between described voltage conversion circuit and ground.
Preferably, described the second reference voltage is less than described the 4th reference voltage.
Above-mentioned resonant transform circuit reduces the power loss under underloading or Light Condition, reduces burst mode switching times simultaneously, has extended circuit lifetime.
Accompanying drawing explanation
Fig. 1 is the module map of resonant transform circuit one execution mode of the present invention.
Fig. 2 is the module map of another execution mode of resonant transform circuit of the present invention.
Fig. 3 is the module map of the another execution mode of resonant transform circuit of the present invention.
Fig. 4 is the circuit diagram of resonant transform circuit one execution mode of the present invention.
Main element symbol description
External power source 10
Resonant transform circuit 20
Power receiving equipment 30
Voltage conversion circuit 200
Current rectifying and wave filtering circuit 202
The first sampling unit 204
The second sampling unit 206
Burst testing circuit 208
The first comparing unit 2082
The first error amplifying unit 2084
The second comparing unit 2086
Burst output unit 2088
Feedback circuit 210
The second error amplifying unit 2102
Feedback signal output unit 2104
The first to second diode D1, D2
First to fourth capacitor C 1, C2, C3, C4
The first to the 7th resistance R 1, R2, R3, R4, R5, R6,
R7
The first inductance L 1
The first to second field-effect transistor Q1, Q2
The first to second optocoupler transducer Q3, Q4
The first to second amplifier A1, A2
The first to second comparator EA1, EA2
Pwm controller U1
Transformer T1
First to fourth reference voltage Vref 1, Vref2, Vref3, Vref4
Following embodiment further illustrates the present invention in connection with above-mentioned accompanying drawing.
Embodiment
Fig. 1 is the module map of resonant transform circuit 20 1 execution modes of the present invention.In the present embodiment, resonant transform circuit 20 is converted to the required operating voltage of power receiving equipment 30 by external power source 10 input voltages.Resonant transform circuit 20 comprises voltage conversion circuit 200, current rectifying and wave filtering circuit 202, the first sampling unit 204, the second sampling unit 206, burst testing circuit 208.Voltage conversion circuit 200 is electrically connected external power source 10, converts external power source 10 input voltages to first voltage.Current rectifying and wave filtering circuit 202 is electrically connected voltage conversion circuit 200 and power receiving equipment 30, for the first voltage being carried out to rectifying and wave-filtering and exporting second voltage, so that power receiving equipment 30 is powered.The first sampling unit 204 is electrically connected at power receiving equipment 30, for convection current, through the electric current of power receiving equipment 30, samples and exports the first sampled voltage of sample rate current.The second sampling unit 206 is electrically connected current rectifying and wave filtering circuit 202, according to the second voltage of current rectifying and wave filtering circuit 202 outputs, exports the second sampled voltage.Burst testing circuit 208 is electrically connected voltage conversion circuit 200, the first sampling unit 204 and the second sampling unit 206, according to the second sampled voltage output burst of the first sampled voltage of the first sampling unit 204 outputs and the second sampling unit 206 outputs.Voltage conversion circuit 200 also regulates the first voltage according to the burst of burst testing circuit 208 outputs.In the present embodiment, when voltage conversion circuit 200 receives the burst of burst testing circuit 208 outputs, voltage conversion circuit 200 break-ofves, now the first voltage is zero.
As to further improvement of the present invention, resonant transform circuit 20 also comprises feedback circuit 210, as shown in Figure 2.Feedback circuit 210 is electrically connected the second sampling unit 206 and voltage conversion circuit 200, according to the second sampled voltage output feedback signal of the second sampling unit 206 outputs, voltage conversion circuit 200 also regulates the first voltage according to the feedback signal of feedback circuit 210 outputs.In the present embodiment, voltage conversion circuit 200 reduces the frequency of the first voltage of output according to the feedback signal of feedback circuit 210 outputs.
Fig. 3 is the module map of resonant transform circuit 20 another execution modes of the present invention.In the present embodiment, resonant transform circuit 20 is converted to the required operating voltage of power receiving equipment 30 by external power source 10 input voltages.Resonant transform circuit 20 comprises voltage conversion circuit 200, current rectifying and wave filtering circuit 202, the first sampling unit 204, the second sampling unit 206, burst testing circuit 208.
In the present invention's one specific embodiment, voltage conversion circuit 200 comprises Pwm controller U1, switch element 2002, resonant element 2004.Switch element 2002 is electrically connected at external power source 10 and Pwm controller U1.Resonant element 2004 is electrically connected at switch element 2002 and current rectifying and wave filtering circuit 202.Current rectifying and wave filtering circuit 202 comprises rectification unit 2022 and filter unit 2024.Rectification unit 2022 is electrically connected at resonant element 2004 and filter unit 2024.
When being not less than the second predeterminated voltage, exports the second sampled voltage that in the present embodiment, burst testing circuit is less than the first predeterminated voltage and the second sampling unit 206 at the first sampled voltage of the first sampling unit 204 burst.In the present embodiment, the first predeterminated voltage is that the first reference voltage Vref 1, the second predeterminated voltage is the second reference voltage Vref 2.
In the present embodiment, burst testing circuit 208 comprises the first comparing unit 2082, the first error amplifying unit 2084, the second comparing unit 2086, burst output unit 2088.The first comparing unit 2082 is electrically connected the first sampling unit 204 and the second comparing unit 2086, according to the first sampled voltage of the first reference voltage Vref 1 receiving and the first sampling unit 204 outputs, exports the first comparison signal.The first error amplifying unit 2084 is electrically connected the second sampling unit 206, the second comparing unit 2086, according to the second sampled voltage of the second reference voltage Vref 2 receiving and the second sampling unit 206 outputs, exports the first error signal.The second comparing unit 2086 is exported the second comparison signal according to the first error signal of the first comparison signal of the first comparing unit 2082 outputs and the first error amplifying unit 2084 outputs.Burst output unit 2088 is electrically connected the second comparing unit 2086 and Pwm controller U1, according to the 3rd reference voltage Vref 3 output bursts of the second comparison signal of the second comparing unit 2086 outputs and reception, with the first voltage of regulation voltage change-over circuit 200 outputs.
In the present embodiment, feedback circuit 210 is exported described feedback signal when the second sampled voltage of the second sampling unit 206 outputs is less than the 3rd predeterminated voltage.In the present embodiment, the 3rd predeterminated voltage is the 4th reference voltage Vref 4.
In the present embodiment, feedback circuit 210 comprises the second error amplifying unit 2102, feedback signal output unit 2104.The second error amplifying unit 2102 is electrically connected the second sampling unit 206, according to the 4th reference voltage Vref 4 output the second error signals of the second sampled voltage of the second sampling unit 206 outputs and reception.Feedback signal output unit 2104 is electrically connected at the second error amplifying unit 2102 and Pwm controller U1, according to the second error signal output feedback signal of the second error amplifying unit 2102 outputs.Pwm controller U1 regulates the first voltage according to the feedback signal of feedback signal output unit 2104 outputs.
Fig. 4 is the circuit diagram of resonant transform circuit 20 1 execution modes of the present invention.In the present embodiment, resonant transform circuit 20 comprises voltage conversion circuit 200, current rectifying and wave filtering circuit 202, the first sampling unit 204, the second sampling unit 206, burst testing circuit 208, feedback circuit 210.Voltage conversion circuit 200 comprises Pwm controller U1, switch element 2002 and resonant element 2004.Switch element 2002 comprises the first field-effect transistor Q1, the second field-effect transistor Q2.Resonant element 2004 comprises the first inductance L 1, the first capacitor C 1, transformer T1.Pwm controller U1 is electrically connected burst testing circuit 208 and feedback circuit 210.Transformer T1 comprises input, output, the input of transformer T1 comprises high voltage input terminal, low pressure input, the output of transformer T1 comprises the first high-voltage output end, the second high-voltage output end and low-voltage output, and the output of transformer T1 is electrically connected at current rectifying and wave filtering circuit 202.The grid of the first field-effect transistor Q1 is electrically connected at Pwm controller U1, and the source electrode that the drain electrode of the first field-effect transistor Q1 is electrically connected at external power source 10, the first field-effect transistor Q1 is electrically connected at the high voltage input terminal of transformer T1.The grid of the second field-effect transistor Q2 is electrically connected at Pwm controller U1, and the drain electrode of the second field-effect transistor Q2 is electrically connected at the source electrode of the first field-effect transistor Q1, the source ground of the second field-effect transistor Q2.The first inductance L 1 is electrically connected between the source electrode of the first field-effect transistor Q1 and the high voltage input terminal of transformer T1.First capacitor C 1 one end is electrically connected at the low pressure input of transformer T1, other end ground connection.Pwm controller U1 controls the first field-effect transistor Q1, the second field-effect transistor Q2 alternate conduction, in other words, when the first field-effect transistor Q1 conducting, the second field-effect transistor Q2 disconnects, during the second field-effect transistor Q2 conducting, the first field-effect transistor Q1 disconnects.When the first field-effect transistor Q1 conducting, the second field-effect transistor Q2 disconnects, and now the output dc voltage of external power source 10 is sent to transformer T1 by the first field-effect transistor Q1, and the first inductance L 1 is carried out energy storage simultaneously.When the second field-effect transistor Q2 conducting, the first field-effect transistor Q1 disconnects, and continues to maintain transformer T1 is powered by the first inductance L 1 electric discharge.Resonant element 2004 is inductance inductance capacitance network (LLC) resonant transform circuit.
In the present embodiment, the first field-effect transistor Q1 is N-type metal oxide semiconductor field effect tube, and the second field-effect transistor Q2 is N-type metal oxide semiconductor field effect tube.In other embodiments, the first field-effect transistor Q1, the second field-effect transistor Q2, also can be P-type mos field effect transistor or transistor.
In the present embodiment, current rectifying and wave filtering circuit 202 comprises rectification unit 2022 and filter unit 2024.Rectification unit 2022 comprises the first diode D1, the second diode D2.Filter unit is the second capacitor C 2.The first diode D1 positive pole is electrically connected at the first high-voltage output end of transformer T1, and negative pole is electrically connected at power receiving equipment 30.The second diode D2 positive pole is electrically connected at the second high-voltage output end of transformer T1, and negative pole is electrically connected at the common port of the first diode D1 and power receiving equipment 30.Second capacitor C 2 one end are electrically connected at the common port of the first diode D1 and the second diode D2, first end ground connection.By the first diode D1, the second diode D2, the second capacitor C 2, realize the voltage of transformer T1 output is carried out to rectification, filtering, to export second voltage.
In the present embodiment, the first sampling unit 204 is the first resistance R 1.First resistance R 1 one end is electrically connected at power receiving equipment 30 and burst testing circuit 208, other end ground connection.By the first resistance R 1 convection current, through the electric current of power receiving equipment 30, sample and convert sample rate current to first sampled voltage and export burst testing circuit 208 to.The first sampling unit 204 also can be induction coil, and the sample circuit that also can be other prior art is realized the sampling of electric current.In the present invention's one specific embodiment, the resistance of the first sampled voltage=sample rate current (electric current of the power receiving equipment 30 of flowing through) the * the first resistance R 1.
In the present embodiment, the second sampling unit 206 comprises the second resistance R 2, the 3rd resistance R 3.Second resistance R 2 one end are electrically connected at current rectifying and wave filtering circuit 202, and the other end is electrically connected at burst testing circuit 208.The 3rd resistance R 3 one end are electrically connected at the common port of the second resistance R 2 and burst testing circuit 208, other end ground connection.In the present embodiment, can regulate the resistance of the second resistance R 2, the 3rd resistance R 3 to regulate the scale of the second sampled voltage of the second sampling unit 206 outputs and the second voltage of current rectifying and wave filtering circuit 202 outputs according to actual conditions.In the present invention's one specific embodiment, the second sampled voltage=second voltage * (resistance of R3/(resistance of resistance+R2 of R3)).
In the present embodiment, burst testing circuit 208 comprises the first comparing unit 2082, the first error amplifying unit 2084, the second comparing unit 2086, burst output unit 2088.The first comparing unit 2082 comprises the first comparator EA1, the 4th resistance R 4.The first error amplifying unit 2084 comprises the first amplifier A1, the 3rd capacitor C 3.The second comparing unit 2086 comprises the 5th resistance R 5, the first optocoupler transducer Q3.Burst output unit 2088 comprises the second comparator EA2, the 6th resistance R 6.The first optocoupler transducer Q3 comprises input and output, and the input of the first optocoupler transducer Q3 comprises first input end, the second input, and the output of the first optocoupler transducer Q3 comprises the first output, the second output.The first optocoupler transducer Q3 input is emission part, inside include light-emitting diode, the first optocoupler transducer Q3 output is acceptance division, inside include phototriode, the first optocoupler transducer Q3 input and the first optocoupler transducer Q3 output are coupled by light, realize the transmission of signal by the variation of luminous intensity being converted to the variation of the signal of telecommunication.The first comparator EA1 comprises positive input, reverse input end and output, the positive input of the first comparator EA1 receives the first reference voltage Vref 1, the reverse input end of the first comparator EA1 is electrically connected at the common port of the first resistance R 1 and power receiving equipment 30, and the output of the first comparator EA1 is electrically connected at the 4th resistance R 4 and the 5th resistance R 5.The 4th resistance R 4 one end are electrically connected at the positive input of the first comparator EA1, and the other end is electrically connected at the output of the first comparator EA1.The 5th resistance R 5 one end are electrically connected at the output of the first comparator EA1, and the other end is electrically connected at the first input end of the first optocoupler transducer Q3.The first amplifier A1 comprises positive input, reverse input end and output, the positive input of the first amplifier A1 receives the second reference voltage Vref 2, the reverse input end of the first amplifier A1 is electrically connected at the common port of the second resistance R 2 and the 3rd resistance R 3, and the output of the first amplifier A1 is electrically connected at the second input of the first optocoupler transducer Q3.The 3rd capacitor C 3 one end are electrically connected at the reverse input end of the first amplifier A1, and the other end is electrically connected at the common port of the first amplifier A1 and the first optocoupler transducer Q3.The 6th resistance R 6 one end are electrically connected at external power source 10, and the other end is electrically connected at the first output of the first optocoupler transducer Q3.The second output head grounding of the first optocoupler transducer Q3.The second comparator EA2 comprises positive input, reverse input end and output, the positive input of the second comparator EA2 receives the 3rd reference voltage Vref 3, the reverse input end of the second comparator EA2 is electrically connected at the common port of the 6th resistance R 6 and the first optocoupler transducer Q3, and the output of the second comparator EA2 is electrically connected at Pwm controller U1.
Under initial condition, resonant transform circuit is in normal mode of operation.The second sampled voltage of the second sampling unit 206 outputs is not less than the second reference voltage Vref 2.Now, the partial pressure value of the first resistance R 1 is greater than the first reference voltage Vref 1, the first comparator EA1 is output as low level, the first amplifier A1 is output as low level, the first optocoupler transducer Q3 is in cut-off state, and the second comparator EA2 reverse input end voltage is the direct voltage of external power source 10 outputs, and it is greater than the 3rd reference voltage Vref 3, the second comparator EA2 is output as low level, and burst testing circuit 208 is exported without burst.When the power reduction of power receiving equipment 30, the second voltage of current rectifying and wave filtering circuit 202 outputs raises, the second sampled voltage of the second sampling unit 206 outputs also raises, and the current reduction of the power receiving equipment 30 of flowing through, the sample rate current that the first sampling unit 204 gathers also reduces, that is first sampled voltage reduce, the partial pressure value of the first resistance R 1 reduces, when the power reduction of power receiving equipment 30 is during to a critical value, the first sampled voltage of the first sampling unit 204 outputs is less than the first predeterminated voltage, that is the partial pressure value of the first resistance R 1 is less than the first reference voltage Vref 1, the first comparator EA1 is output as high level, the second sampled voltage of the second sampling unit 206 outputs is greater than the second reference voltage Vref 2, the first amplifier A1 output is electronegative potential, now the first optocoupler transducer Q3 is in conducting state, the second comparator EA2 reverse input end voltage reduces, its magnitude of voltage is close to 0, it is less than the 3rd reference voltage Vref 3, the second comparator EA2 output is high level, burst testing circuit 208 produces and exports burst to Pwm controller U1, Pwm controller U1 receives break-off after burst, voltage conversion circuit 200 Non voltage outputs, the first voltage is 0, resonant transform circuit 20 enters burst mode, the second capacitor C 2 electric discharges, the second voltage of current rectifying and wave filtering circuit 202 outputs reduces, the second sampled voltage of the second sampling unit 206 outputs also reduces, when the second sampled voltage of the second sampling unit 206 output is decreased to while being less than the second predeterminated voltage, in other words, the second sampled voltage of the second sampling unit 206 outputs is decreased to and is less than the second reference voltage Vref 2, the first amplifier A1 output is high level, the first optocoupler transducer Q3 is in cut-off state, the second comparator EA2 reverse input end voltage raises, it is greater than the 3rd reference voltage Vref 3, the second comparator EA2 output changes electronegative potential into, burst testing circuit 208 is exported without burst, resonant transform circuit 20 exits burst mode, Pwm controller U1 recovers normal work, resonant transform circuit 20 enters normal mode of operation.The switching of resonant transform circuit 20 repetitive burst patterns and normal mode of operation, so no longer describe in detail.
In the present embodiment, feedback circuit 210 comprises the second error amplifying unit 2102, feedback signal output unit 2104.The second error amplifying unit 2102 comprises the 4th capacitor C 4, the second amplifier A2.Feedback signal output unit 2104 comprises the 7th resistance R 7, the second optocoupler transducer Q4.The second optocoupler transducer Q4 comprises input and output, and the second optocoupler transducer Q4 input comprises first input end, the second input, and the second optocoupler transducer Q4 output comprises the first output, the second output.The second optocoupler transducer Q4 input is emission part, inside include light-emitting diode, the second optocoupler transducer Q4 output is acceptance division, inside include phototriode, the second optocoupler transducer Q4 input and the second optocoupler transducer Q4 output are coupled by light, realize the transmission of signal by the variation of luminous intensity being converted to the variation of the signal of telecommunication.The 7th resistance R 7 one end are electrically connected at the common port of current rectifying and wave filtering circuit 202 and the second resistance R 2, and the other end is electrically connected at the first input end of the second optocoupler transducer Q4.The second amplifier A2 comprises positive input, reverse input end and output, the positive input of the second amplifier A2 receives the 4th reference voltage Vref 4, the reverse input end of the second amplifier A2 is electrically connected at the common port of the second resistance R 2 and the 3rd resistance R 3, and the output of the second amplifier A2 is electrically connected at the second input of the second optocoupler transducer Q4.The 4th capacitor C 4 one end are electrically connected at the reverse input end of the second amplifier A2, and the other end is electrically connected at the output of the second amplifier A2.
Under initial condition, resonant transform circuit 20 is in normal mode of operation.It is low level that the second sampled voltage of the second sampling unit 206 outputs is not less than the 4th reference voltage Vref 4, the second amplifier A2 outputs, and the second optocoupler transducer Q4 is in conducting state, and its output voltage is the first output voltage.Along with the power reduction of power receiving equipment 30, the second voltage of current rectifying and wave filtering circuit 202 outputs raises, and the second sampled voltage of the second sampling unit 206 outputs also raises.When resonant transform circuit 20 enters burst mode, the second voltage of current rectifying and wave filtering circuit 202 outputs reduces, the second sampled voltage of the second sampling unit 206 outputs also reduces, when the second sampled voltage of the second sampling unit 206 output is decreased to while being less than the 3rd predeterminated voltage, in other words, when the second sampled voltage of the second sampling unit 206 outputs is less than the 4th reference voltage Vref 4, the second amplifier A2 output is high level, the input current of the second optocoupler transducer Q4 of flowing through reduces, the second optocoupler transducer Q4 is output as the second output voltage, utilize the variation of the second optocoupler transducer Q4 output end voltage, realize by the second optocoupler transducer Q4 and change output feedback signal according to the power of power receiving equipment 30.Pwm controller U1 receives the feedback signal of the second optocoupler transducer Q4 output, with output pulse width modulation signal, thereby regulate the time of the first field-effect transistor Q1, the second field-effect transistor Q2 conducting and shutoff, and then regulate LLC resonant transform circuit frequency.In the present embodiment, Pwm controller U1 receives the feedback signal of the second optocoupler transducer Q4 output, thereby extend the time of the first field-effect transistor Q1, the second field-effect transistor Q2 conducting and shutoff, that is reduce the first field-effect transistor Q1, the second field-effect transistor Q2 conducting and turn-off number of times in the unit interval, and then reduce LLC resonant transform circuit frequency, thereby realize, reduce the power loss of resonant transform circuit 20 under underload or Light Condition.
It should be noted that, in the present embodiment, the first reference voltage Vref 1, the second reference voltage Vref 2, the 3rd reference voltage Vref 3, the 4th reference voltage Vref 4 can specifically arrange its reference voltage level according to different demands or design, wherein, the second reference voltage Vref 2 preferably needs to be slightly less than the 4th reference voltage Vref 4, for example the second reference voltage Vref 2 equals the 4th reference voltage Vref 4 of 0.99 multiple, can guarantee that like this resonant transform circuit 20 is under burst mode, the voltage providing under normal mode of operation with resonant transform circuit 20 is provided the voltage minimum that offers power receiving equipment 30, the time that the first amplifier A1 output is high potential by low transition simultaneously will be later than the time that the second amplifier A2 output is high potential by low transition, thereby make resonant transform circuit 20 under burst mode, LLC resonant transform circuit is all the time in lower frequency state, transformer T1 primary side is passed to secondary side with ceiling capacity, and then minimizing burst mode switching times, extended circuit lifetime, also reduce the power loss of resonant transform circuit 20 under underloading or Light Condition.
Above-mentioned resonant transform circuit reduces the power loss under underloading or Light Condition, reduces burst mode switching times simultaneously, has extended circuit lifetime.
Claims (21)
1. a resonant transform circuit, for the direct voltage of external power source output is converted to the required operating voltage of power receiving equipment, is characterized in that, described resonant transform circuit comprises:
Voltage conversion circuit, for being electrically connected described external power source, for converting the direct voltage of described external power source output to first voltage;
Current rectifying and wave filtering circuit, for being electrically connected described voltage conversion circuit and described power receiving equipment, for described the first voltage is carried out rectifying and wave-filtering and exports second voltage, so that described power receiving equipment is powered;
The first sampling unit, for being electrically connected described power receiving equipment, for the electric current of the described power receiving equipment of flowing through being sampled and exporting the first sampled voltage of sample rate current;
The second sampling unit, for being electrically connected described current rectifying and wave filtering circuit, for exporting the second sampled voltage according to the second voltage of described current rectifying and wave filtering circuit output; And
Burst testing circuit, be used for being electrically connected described voltage conversion circuit, described the first sampling unit and described the second sampling unit, for exporting burst according to the second sampled voltage of the first sampled voltage of described the first sampling unit output and described the second sampling unit output;
Wherein, described voltage conversion circuit is also for regulating described the first voltage according to described burst.
2. resonant transform circuit as claimed in claim 1, is characterized in that, described voltage conversion circuit comprises:
Pwm controller, be used for being electrically connected at described burst testing circuit, for generation of pulse width modulating signal and according to the pulse width modulating signal of the burst regulation output of described burst testing circuit output, to regulate the first voltage of described voltage conversion circuit output;
Switch element, for being electrically connected at described Pwm controller and described external power source, for the converting direct-current voltage into alternating-current voltage that described external power source is exported; And
Resonant element, for being electrically connected at described switch element and described current rectifying and wave filtering circuit, for converting the alternating voltage of described switch element output to first voltage.
3. resonant transform circuit as claimed in claim 2, is characterized in that,
Described switch element comprises:
The first field-effect transistor, grid is electrically connected at described Pwm controller, and drain electrode is electrically connected at described external power source, and source electrode is electrically connected at described resonant element; And
The second field-effect transistor, grid is electrically connected at described Pwm controller, and drain electrode is electrically connected at the source electrode of described the first field-effect transistor, source ground;
Described resonant element comprises:
Transformer, comprises primary side, secondary side, and described primary side comprises high voltage input terminal, low pressure input, and described secondary side comprises the first high-voltage output end, the second high-voltage output end and low-voltage output, and described secondary side is electrically connected at described current rectifying and wave filtering circuit;
The first inductance, is electrically connected between the source electrode of described the first field-effect transistor and the high voltage input terminal of described transformer; And
The first electric capacity, one end is electrically connected at the low pressure input of described transformer, other end ground connection.
4. resonant transform circuit as claimed in claim 1, is characterized in that, described current rectifying and wave filtering circuit comprises:
Rectification unit, for being electrically connected between described voltage conversion circuit and described power receiving equipment, for the first voltage of described voltage conversion circuit output is carried out to rectification; And
Filter unit, for being electrically connected between described rectification unit and described power receiving equipment, for the first voltage of described voltage conversion circuit output is carried out to filtering.
5. resonant transform circuit as claimed in claim 4, is characterized in that, described rectification unit comprises:
The first diode, positive pole is electrically connected at described voltage conversion circuit, and negative pole is electrically connected at described power receiving equipment; And
The second diode, positive pole is electrically connected at described voltage conversion circuit, and negative pole is electrically connected at the negative pole of described the first diode;
Wherein said filter unit is the second electric capacity, and one end is electrically connected at the common port of described the first diode and the second diode, other end ground connection.
6. resonant transform circuit as claimed in claim 1, is characterized in that, described the first sampling unit is the first resistance, and one end is electrically connected at described power receiving equipment and described burst testing circuit, other end ground connection.
7. resonant transform circuit as claimed in claim 1, is characterized in that, described the second sampling unit comprises:
The second resistance, one end is electrically connected at described current rectifying and wave filtering circuit, and the other end is electrically connected at described burst testing circuit; And
The 3rd resistance, one end is electrically connected at the other end of described the second resistance, other end ground connection.
8. resonant transform circuit as claimed in claim 1, it is characterized in that, described voltage conversion circuit judges whether break-off according to the burst of described burst testing circuit output, when described voltage conversion circuit detects described burst, described voltage conversion circuit is 0 by described the first voltage-regulation.
9. resonant transform circuit as claimed in claim 1, it is characterized in that, when the second sampled voltage that described burst testing circuit is less than the first predeterminated voltage and described the second sampling unit at the first sampled voltage of described the first sampling unit is not less than the second predeterminated voltage, export described burst.
10. resonant transform circuit as claimed in claim 9, is characterized in that, described burst testing circuit comprises:
The first comparing unit, for comparing the first reference voltage and described the first sampled voltage and exporting the first comparison signal;
The first error amplifying unit, for exporting the first error signal according to the second reference voltage and described the second sampled voltage;
The second comparing unit, for exporting the second comparison signal according to described the first comparison signal and described the first error signal; And
Burst output unit, for exporting burst according to the 3rd reference voltage and described the second comparison signal.
11. resonant transform circuits as claimed in claim 10, is characterized in that, described the first comparing unit comprises:
The first comparator, comprise positive input, reverse input end and output, described positive input is used for receiving described the first reference voltage, and described reverse input end is electrically connected at described the first sampling unit, and described output is electrically connected at described the second comparing unit; And
The 4th resistance, one end is electrically connected at the positive input of described the first comparator, and the other end is electrically connected at the output of described the first comparator.
12. resonant transform circuits as claimed in claim 10, is characterized in that, described the first error amplifying unit comprises:
The first amplifier, comprise positive input, reverse input end and output, described positive input is used for receiving described the second reference voltage, and described reverse input end is electrically connected at described the second sampling unit, and described output is electrically connected at described the second comparing unit; And
The 3rd electric capacity, one end is electrically connected at the reverse input end of described the first amplifier, and the other end is electrically connected at the output of described the first amplifier.
13. resonant transform circuits as claimed in claim 10, is characterized in that, described the second comparing unit comprises:
The 5th resistance, one end is electrically connected at described the first comparing unit; And
The first optocoupler transducer, comprises input and output, and described input is electrically connected between the other end and described the first error amplifying unit of described the 5th resistance, and described output is electrically connected between described burst output unit and ground.
14. resonant transform circuits as claimed in claim 10, is characterized in that, described burst output unit comprises:
The 6th resistance, one end is electrically connected at described external power source, and the other end is electrically connected at described the second comparing unit; And
The second comparator, comprise positive input, reverse input end and output, described positive input is used for receiving described the 3rd reference voltage, described reverse input end is electrically connected at the common port of described the 6th resistance and described the second comparing unit, and described output is electrically connected at described voltage conversion circuit.
15. resonant transform circuits as claimed in claim 10, it is characterized in that, also comprise feedback circuit, be used for being electrically connected described the second sampling unit and described voltage conversion circuit, for the second sampled voltage output feedback signal of exporting according to described the second sampling unit, described voltage conversion circuit is also for regulating described the first voltage according to described feedback signal.
16. resonant transform circuits as claimed in claim 15, is characterized in that, described feedback circuit is exported described feedback signal when the second sampled voltage of described the second sampling unit output is less than the 3rd predeterminated voltage.
17. resonant transform circuits as claimed in claim 15, is characterized in that, described voltage conversion circuit is also for reducing the frequency of the first voltage of output according to described feedback signal.
18. resonant transform circuits as claimed in claim 15, is characterized in that, described feedback circuit comprises:
The second error amplifying unit, for exporting the second error signal according to the second sampled voltage of the 4th reference voltage and described the second sampling unit output; And
Feedback signal output unit, for according to described the second error signal output feedback signal.
19. resonant transform circuits as claimed in claim 18, is characterized in that, described the second error amplifying unit comprises:
The second amplifier, comprise positive input, reverse input end and output, described positive input is used for receiving described the 4th reference voltage, and described reverse input end is electrically connected at described the second sampling unit, and described output is electrically connected at described feedback signal output unit; And
The 4th electric capacity, one end is electrically connected at the reverse input end of described the second amplifier and the common port of described the second sampling unit, and the other end is electrically connected at the output of described the second amplifier.
20. resonant transform circuits as claimed in claim 18, is characterized in that, described feedback signal output unit comprises:
The 7th resistance, one end is electrically connected at described current rectifying and wave filtering circuit; And
The second optocoupler transducer, comprises input and output, and described input is electrically connected between the other end and described the second error amplifying unit of described the 7th resistance, and described output is electrically connected between described voltage conversion circuit and ground.
21. resonant transform circuits as claimed in claim 18, is characterized in that, described the second reference voltage is less than described the 4th reference voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310170176.7A CN104143920A (en) | 2013-05-10 | 2013-05-10 | Resonant transformation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310170176.7A CN104143920A (en) | 2013-05-10 | 2013-05-10 | Resonant transformation circuit |
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|---|---|
| CN104143920A true CN104143920A (en) | 2014-11-12 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310170176.7A Pending CN104143920A (en) | 2013-05-10 | 2013-05-10 | Resonant transformation circuit |
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| CN (1) | CN104143920A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108770124A (en) * | 2018-06-21 | 2018-11-06 | 英飞特电子（杭州）股份有限公司 | A kind of LED drive circuit and lighting apparatus |
| CN114567029A (en) * | 2021-09-30 | 2022-05-31 | 惠州市乐亿通科技有限公司 | Overvoltage protection circuit and charging device |
-
2013
- 2013-05-10 CN CN201310170176.7A patent/CN104143920A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108770124A (en) * | 2018-06-21 | 2018-11-06 | 英飞特电子（杭州）股份有限公司 | A kind of LED drive circuit and lighting apparatus |
| CN108770124B (en) * | 2018-06-21 | 2023-08-18 | 英飞特电子（杭州）股份有限公司 | LED drive circuit and lighting equipment |
| CN114567029A (en) * | 2021-09-30 | 2022-05-31 | 惠州市乐亿通科技有限公司 | Overvoltage protection circuit and charging device |
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Application publication date: 20141112 |