TWI554015B - Single - stage high power return - forward converter and light source system - Google Patents

Description

Single-stage high-power return-forward converter and light source system

The invention relates to a single-stage high-power-return-forward converter and a light source system, in particular to an output power that can be provided when the switching device is turned on, and also has a power output when the switch is turned off, when the switch is turned off. There is still power input, there is power input when the switch is turned on, and a single-stage flyback converter and light source system with Power Factor Correction (PFC) function, and a leakage inductance energy recovery circuit is added to reduce the switch. The voltage across the board and the efficiency of the circuit to meet the high power, high efficiency and low cost of the current light source system.

With the advancement of modern technology and the rapid development of portable electronic products, the performance and applications of converters have received increasing attention. In recent years, due to the great advancement of power electronics technology and the development of nanotechnology, electronic equipment has become increasingly thin and light, energy-saving, and cost-reducing. The internal power converters also need to be light, short, and energy-saving. Trend design for increasing power and reducing production costs.

Please refer to the first figure, which is a schematic diagram of a conventional flyback converter 1. The conventional flyback converter 1 includes a power factor correction stage 11 , a power stage 12 and a feedback stage 13 ; the power factor correction stage 11 includes a power a factor correction inductor LPFC, a power factor correction switch SPFC, a power factor correction control circuit 111 and an input storage capacitor Cin, the power factor correction circuit 111 is controlled by a current loop and a voltage loop on the receiving circuit to control the power The turn-on cycle time of the factor correction switch SPFC is used to actively adjust the current mode; the power factor correction inductor LPFC uses the filter characteristic of the inductor to achieve the passive adjustment of the current mode; and the input storage capacitor Cin is used to stabilize The power factor corrects the voltage output by stage 11.

The power stage 12 includes an electronic sensing device 121, a switching device 122, a driving circuit 123, and an output storage capacitor 124. The electronic sensing device 121 has a diode D, a primary sensing circuit LP, and a primary electronic device. The sensing circuit LS; wherein the diode D acts as a rectifier and only allows current flowing in a single direction, and the primary sensing circuit LP and the secondary electronic sensing circuit LS are implemented by a coupled inductor or a transformer. It is used to convert the input voltage Vin into an output voltage Vout. The output storage capacitor 124 is electrically connected to the secondary electronic induction circuit LS to stabilize the output voltage of the secondary side. The switching device 122 is electrically connected to the electronic sensing device 121 for selectively establishing an electrical connection according to a control signal. The driving circuit 123 is coupled to the switching device 122 for determining and selecting according to an indication signal. The cycle time of the electrical connection is adjusted to generate the control signal.

The feedback stage 13 is electrically connected to the electronic sensing device 121 to receive an output voltage generated by the secondary electronic sensing circuit LS, and performs comparison of the output voltage with the predetermined voltage to generate the indication signal.

When the switching device 122 is turned on, the current from the power source begins to flow to the primary sensing circuit LP, the primary sensing circuit LP begins to store energy until the switching device 12 is turned off; and when the switching device 12 is turned off, the primary sensing circuit LP begins to release. The energy generates magnetic energy until the primary induction circuit LP is depleted, and the magnetic energy is transmitted through the iron powder core or other conductor, and the magnetic energy is coupled to the secondary electronic induction circuit LS, so that the secondary electronic induction circuit LS is magnetically An induced current is generated, which is the output current.

It can be known from the above that the output power of the conventional flyback converter is determined by the energy storage capacity of the primary sensing circuit LP or the opening time of the switching device 12, and the energy storage energy of the primary sensing circuit LP. Restricted by the volume of the electronic sensing device 121; and although the power factor correction stage 11 can improve the power factor, the resulting parts and manufacturing costs are also increased, and how can the cost and product volume be particularly important today? Providing greater output power is an important issue for flyback converters without increasing product size and excessive cost.

Therefore, in order to solve the problem of the conventional method, the inventor has carefully studied and experimented and developed the single-stage high-power-return-forward converter and light source system proposed in this case, which will be in a flyback converter. Separating the secondary side of the electronic sensing circuit into a first secondary electronic sensing circuit and a second secondary electronic sensing circuit, so that the first secondary electronic sensing circuit and the second secondary electronic sensing circuit are respectively turned on and off at the switching device The power output is generated to make the converter have the effect of a forward converter output; in addition, a power factor correction inductor is directly connected to the switching device of the original power stage, and the switching device replaces the original power factor correction switch, and utilizes When the circuit is in steady state, the on-time of the switching device is fixed, so that the current on the power factor correction inductor is proportional to the input voltage, so that the flyback converter does not need to be equipped with a power factor correction switch and a power factor correction circuit, and the same can be achieved. The power factor correction function whereby the more conventional flyback converter of the present invention provides greater output power and lowers manufacturing and material costs.

For the foregoing purposes, the present invention provides a high power output flyback converter including: a power factor correction inductor located at the input of the single stage high power factor return-forward converter An electronic sensing device electrically connected to the power factor correction inductor, the electronic sensing device having a plurality of diodes, a primary electronic sensing circuit, a first secondary electronic sensing circuit, and a first a second secondary electronic sensing circuit, the plurality of diodes are electrically connected to the first secondary electronic sensing circuit and the second secondary electronic sensing circuit respectively; a switching device electrically connected to the power factor correcting inductor And the electronic sensing device for selectively establishing an electrical connection according to a control signal; a driving circuit connected to the switching device for generating the control signal according to an indication signal; a feedback stage The feedback stage is electrically connected to the secondary side of the electronic sensing device for performing a comparison of an output voltage with the predetermined voltage to generate the indication signal; An output inductor is electrically connected to the first secondary electronic induction circuit for suppressing or storing energy output by the first secondary electronic induction circuit; an output storage capacitor, the output storage capacitor is electrically connected to The secondary side of the electronic sensing device stabilizes the output voltage of the secondary side; an input storage capacitor, the input energy storage A capacitor is electrically coupled to the primary electronic sensing circuit to store or release energy through the primary electronic sensing circuit.

The single-stage high-power-return-forward converter and light source system proposed in this case has the following beneficial effects:

1. Electrically connected to a switching device through a power factor correction inductor, so that the single-stage high-power return-forward converter does not need to be additionally equipped with a power factor correction switch and a power factor correction circuit, and can also achieve a power factor. Corrected features.

2. The first secondary electronic sensing circuit inside the electronic sensing device can perform energy output when the switching device is turned on to increase the output power.

3. The output inductor can suppress the energy output of the first secondary electronic induction circuit when the switching device is turned on to avoid damage of the diode.

4. The output inductor can absorb the energy output of the first secondary electronic induction circuit when the switching device is turned on to perform energy output when the switching device is turned off.

5. When the switching device is turned off, the energy stored on the primary side is output through the second inductive circuit.

6. The total output power of the flyback-forward converter can be more than 150W by the energy output of the first secondary electronic induction circuit and the second secondary electronic induction circuit, which is more suitable for the medium and high power light source system. Power demand.

7. The storage capacitor on the primary side has energy input regardless of whether the switch is turned on or off.

1‧‧‧return converter

11‧‧‧Power factor correction stage

111‧‧‧Power factor correction circuit

12‧‧‧Power level

121‧‧‧Electronic sensing device

122‧‧‧Switching device

123‧‧‧Drive circuit

124‧‧‧ Output storage capacitor

13‧‧‧Reward level

Cin‧‧‧ input storage capacitor

D‧‧‧ diode

LPFC‧‧‧Power Factor Correction Inductor

LP‧‧‧Primary electronic sensing circuit

LS‧‧‧Secondary electronic sensing circuit

Vin‧‧‧Input voltage signal

Vout‧‧‧ output voltage signal

SPFC‧‧‧Power Factor Correction Switch

2‧‧‧Single-stage high-power return-forward converter

21‧‧‧Power factor correction inductor

22‧‧‧Electronic sensing device

221‧‧‧Auxiliary sensing circuit

222‧‧‧Primary leakage inductance energy recovery circuit

2221‧‧‧Leakage Inductance Energy Storage Capacitor

2222‧‧‧Leakage inductance energy recovery winding

2223‧‧‧Signal amplification circuit

2224‧‧‧ Current sense resistor

2225‧‧‧ Valley Detection Circuit

23‧‧‧Switching device

24‧‧‧Drive Circuit

25‧‧‧Feedback circuit

26‧‧‧Output inductance

261‧‧‧Output inductance sensing circuit

27‧‧‧ Output storage capacitor

28‧‧‧Input storage capacitor

29‧‧‧ Zero current detection circuit

LS1‧‧‧First secondary electronic sensing circuit

LS2‧‧‧Second secondary electronic sensing circuit

D1‧‧‧ diode

D2‧‧‧ diode

R‧‧‧Output load

I28‧‧‧Input storage capacitor current

IO1‧‧‧First secondary electronically induced current

I21‧‧‧Power Factor Correction Inductor Current

IO2‧‧‧Second secondary electronic induced current

I26‧‧‧ Output inductor current

D3‧‧‧ diode

3‧‧‧Single-level high-power-return-direct converter light source system

31‧‧‧Power factor correction inductor

32‧‧‧Electronic sensing device

33‧‧‧Switching device

34‧‧‧Drive circuit

35‧‧‧Feedback circuit

6‧‧‧Output inductance

37‧‧‧ Output storage capacitor

38‧‧‧Input storage capacitor

39‧‧‧Light source module

D4‧‧‧Lighting diode

First picture: Circuit diagram of a conventional flyback converter.

Second Figure: Circuit diagram of a single stage high power factor flyback-forward converter of the present invention.

Third Embodiment: An equivalent circuit diagram of the driving circuit and the feedback stage in the operation mode 1 is omitted in the embodiment of the present invention.

Fourth: The embodiment of the present invention omits the equivalent circuit diagram of the driving circuit and the feedback stage in the operation mode 2.

Fifth Figure: A first embodiment of the present invention.

Figure 6: A second embodiment of the invention.

Seventh embodiment: A third embodiment of the present invention.

Eighth view: A fourth embodiment of the present invention.

Ninth view: A fifth embodiment of the present invention.

Tenth Figure: A sixth embodiment of the present invention.

Figure 11: A seventh embodiment of the present invention.

Twelfth Figure: An eighth embodiment of the present invention.

Thirteenth Diagram: Circuit diagram of the light source system of the single stage high power factor return-forward converter of the present invention.

In order to provide a further understanding of the features and technical aspects of the present invention, reference should be made to the following detailed description of the invention and the accompanying drawings.

In order to help the implementer to clarify the essence of the present invention, please refer to the second figure, which is a single-stage high-power-return-forward converter 2 of the present invention, which is a single-stage high-performance return-shun-shun The converter 2 includes a power factor correction inductor 21 located at the input of the single-stage high-power flyback-forward converter 2; an electronic sensing device 22, the electronic sensing device 22 Electrically connected to the power factor correction inductor 21, the electronic sensing device 22 has a plurality of diodes D1, D2, a primary electronic sensing circuit LP, a first secondary electronic sensing circuit LS1, and a second secondary The electronic induction circuit LS2, the plurality of diodes D1, D2 are electrically connected to the first secondary electronic induction circuit LS1 and the second secondary electronic induction circuit LS2, respectively, and the electronic induction circuit LS2 and the diode D2 can be increased. Output power 50% to the output capacitor 27; a switching device 23, the switching device 23 is electrically connected to the power factor correction inductor 21 and the electronic sensing device 22, used to selectively establish an electrical connection according to a control signal; a driving circuit 24, the driving circuit is connected to the switching device for generating the control signal according to an indication signal; a feedback stage 25, the feedback stage 25 is electrically connected to the secondary side of the electronic sensing device 22 for performing an comparison of an output voltage with the predetermined voltage to generate the indication signal; an output inductor 26 electrically connected to the first secondary The electronic sensing circuit LS1 is configured to suppress or store the energy output by the first secondary electronic sensing circuit LS1; an output storage capacitor 27 is electrically connected to the secondary side of the electronic sensing device 22, The output voltage of the secondary side is stabilized; an input storage capacitor 28 is electrically connected to the primary electronic sensing circuit LP to store or release energy passing through the primary electronic sensing circuit LP.

The purpose of the driving circuit 24 and the feedback stage 13 is to control the switching of the switching device 23. The operation principle is the same as that of the prior art. In order to facilitate the description of the operation principle of the present invention, it is simplified in the circuit diagram of the embodiment, and details are not described below.

3 is an equivalent circuit diagram omitting a driving circuit and a feedback stage in an operation mode 1 according to an embodiment of the present invention, wherein R is an output load; when the switching device 23 starts to conduct, the input current starts to charge the power factor correction inductor 21, and A power factor correction inductor current I21 is generated to flow through the switching device 23; and the input storage capacitor 28 releases the energy stored in the operation mode 2 in the previous cycle, thereby generating the input storage capacitor current I28 via the primary electronic sensing circuit LP. Coupling the energy to the first secondary electronic sensing circuit LS1; the first secondary electronic sensing circuit LS1 generates a first secondary electronic induced current IO1 due to the coupling of the electronic sensing device 22, the first secondary electronically induced current The IO1 passes through the diode D1 and the output inductor 26, and is used by the output storage capacitor 27 to store and output the load R. The output inductor 26 is used for storing and suppressing the first secondary electronic induced current IO1 to prevent the current flow from being excessively burned. Polar body D1.

The fourth diagram is an equivalent circuit diagram in which the driving circuit and the feedback stage are in operation mode 2, wherein R is an output load, and the power factor correction inductor 21 that stores energy in the operation mode 1 starts when the switching device 23 is turned off. Discharge, the power factor correction inductor current I21 flows through the primary electronic induction circuit LP and charges the input storage capacitor 28, and the power factor correction inductor current I21 flows through the primary electron The energy of the sensing circuit LP and the stored energy of the primary electronic sensing circuit LP itself in the operating mode are coupled to the second secondary electronic sensing circuit LS2 to generate a second secondary electronically induced current IO2, the second secondary electron The induced current IO2 is stored through the diode D2 to the output storage capacitor 27 and the output load R; and the output inductor 26, which also stores energy in the operation mode 1, also releases the output inductor current I26 to provide the output storage capacitor 27 for storage. And the output load R is used.

The fifth figure is a first embodiment of the present invention. When the switching device 23 is turned on by the circuit of the primary electronic sensing circuit LP in the center tapping coil, the current output by the power factor correcting inductor 21 flows through the primary electronic sensing circuit. A portion of the current of the LP charges the input storage capacitor 28, and a portion of the current flows through the switching device 23, thereby reducing the current flow through the switching device 23 to reduce the current demand specification of the switching device 23.

The sixth embodiment is a second embodiment of the present invention. When the diode D3 is added to the first secondary electronic sensing circuit LS1, the output inductor current I26 of the output inductor 26 in the operation mode 2 does not pass the first A secondary electronic induction circuit LS1 is reflected back to the second secondary electronic induction circuit LS2 to slow down the attenuation speed of the output inductor current I26 and boost the output power of the single-stage high-power flyback-forward converter 2. And reducing the current burden of the second secondary electronic induction circuit LS2 diode D2.

In order to avoid the energy loss caused by the Zero Current Switching (ZCS), as shown in the seventh figure, an auxiliary sensing circuit 221 is coupled to the electronic sensing device 22, and a zero current detecting circuit (Zero) is provided. The current Detecting Circuit (ZCD Circuit) 29 is coupled to the auxiliary sensing circuit 221 and the driving circuit 24; the auxiliary sensing circuit 221 can sense the change of the magnetic field in the electronic sensing device 22, thereby confirming the primary electronic sensing circuit LP. Whether the current flows in the first secondary electronic sensing circuit LS1 and the second secondary electronic sensing circuit LS2; and the zero current detecting circuit 29 is configured to detect the auxiliary sensing circuit 221 and transmit the indication signal Up to the driving circuit 24, thereby controlling the operation of the switching device 23; the primary electronic sensing circuit IP, the first secondary electronic sensing circuit LS1, and the Switching is performed after the current of the second secondary electronic induction circuit LS2 is zero to reduce the energy consumption of the non-zero current switching.

However, if the second embodiment of the present invention has a zero current switching function, as shown in the eighth figure, in addition to the electronic sensing device 22 coupling the auxiliary sensing circuit 221, the output inductor 26 needs to add an additional output. Inductive sensing circuit 261; the zero current detecting circuit 29 is coupled to the auxiliary sensing circuit 221, the driving circuit 24 and the output inductor sensing circuit 261; since the secondary side of the electronic sensing device 22 is equipped with a diode D3, so that a part of the current on the secondary side of the electronic sensing device 22 does not pass through the first secondary electronic sensing circuit LS1 and the second secondary electronic sensing circuit LS2, and the output is sensed through the output inductor sensing circuit 261. The switching operation of the switching device 23 is performed only after the current on the inductor 26 confirms that the condition of zero current switching has been satisfied.

Further, as shown in the ninth embodiment of the fifth embodiment of the present invention, a primary leakage inductance energy recovery circuit 222 can be added to the single-stage high-power flyback-forward converter 2, the primary leakage inductance energy. The recovery circuit 222 is coupled to the primary electronic induction circuit LP and the switching device 23; the primary leakage inductance energy recovery circuit 222 includes a leakage inductance energy storage capacitor 2221 and a leakage inductance energy recovery winding 2222 when the switching device 23 is turned off. The leakage inductance energy recovery capacitor 2221 can store the leakage inductance energy of the primary side of the electronic sensing device 22. When the switching device 23 is turned on, the leakage inductance energy recovery capacitor 2221 will be stored in the leakage inductance of the recovery capacitor 2221. The energy is transmitted through the leakage inductance energy recovery winding 2222 to the primary electronic induction circuit LP, and the leakage inductance energy is transmitted to the input storage capacitor 28; this design can recover the leakage inductance energy and reduce the switching device 23 The voltage is across to avoid the next time the switching device 23 is turned off, the surge voltage caused by the leakage inductance energy in the circuit damages the switching device 23 to extend the switch Set the service life of 23.

In the fifth embodiment of the present invention, the primary leakage inductance energy recovery circuit 222 includes the leakage inductance energy recovery winding 2222. Therefore, if the fifth embodiment of the present invention has a zero current switching function, it can be as shown in the tenth figure. As shown, the leakage inductance energy recovery winding 2222 is coupled in a circuit manner of a center tap coil. The zero current detecting circuit 29 is coupled to the driving circuit 24, and when the zero current detecting circuit 29 confirms that the leakage inductance energy recovery winding 2222 has a voltage drop of 0, An indication signal is sent to the drive circuit 24 to control the operation of the switching device 23 to meet the conditions of zero current switching.

The eleventh embodiment of the present invention is the seventh embodiment of the present invention. When the switching device 23 is turned on by the circuit of the primary electronic sensing circuit LP in the center tapped coil, the current output by the power factor correcting inductor 21 flows through the primary electronic sensing. A portion of the current of the circuit LP charges the input storage capacitor 28, and a portion of the current flows through the switching device 23, thereby reducing the current flow through the switching device 23 to reduce the current demand specification of the switching device 23. A current sensing resistor 2224 is added under the switch to have a resistance of about 0.025 ohms, and then the voltage of the current sensing resistor is about four times passed through the signal amplifying circuit 2223, and the maximum value is about 0.5 V. When the voltage exceeds When the error voltage in the circuit is feedback, the switch turns-off. Since the series resistance is very small (0.025 ohms), the power consumption is below 1W (assuming the maximum current is 6A), which can reduce the power consumed by the current sensing resistor. , thereby improving efficiency.

The twelfth embodiment is an eighth embodiment of the present invention. The auxiliary induction circuit 221 outputs a zero current signal V _ZCD1 and the output inductor 26 to the output inductor sensing circuit 261 to output a zero current signal V _ZCD2 , and then two zero currents. After the signals are multiplied by the weights of K ₁ and K ₂ respectively, they are added in the Valley detecting circuit. When the output inductor 26 has a current flowing, the zero current is outputted to the output inductor sensing circuit 261. The signal V _ZCD2 signal is a positive voltage. At this time, the zero current signal V _ZCD1 outputted by the auxiliary sensing circuit 221 is a negative voltage when the valley is generated, and the K ₂ weight multiplied by the zero current signal V _{ZCD2 outputted} by the output inductor sensing circuit 261 is compared. Large, so the two signals are still positive after they are added, so the bottom cannot be detected. Until the current of the output inductor 26 is zero, the zero current signal V _ZCD2 outputted to the output inductor sensing circuit 261 is zero voltage, so when the zero current signal V _ZCD1 outputted by the auxiliary sensing circuit 221 generates a negative voltage at the bottom, the two signals After adding in the Valley detecting circuit, the valley bottom of V _ZCD1 can be detected, and the switch device 122 turns-on at the bottom of the valley, which can reduce the switching loss and improve the efficiency.

The thirteenth picture is a circuit diagram of the light source system 3 of the single-stage high-power-return-forward converter of the creation, the single-stage high-power-return-forward converter light source system 3 includes a power factor The inductor 31 is modified, and the power factor correction inductor 31 is located at an input end of the single-stage high-power return-to-forward converter light source system 3; an electronic sensing device 32 is electrically connected to the power factor The inductor 31 is modified. The electronic sensing device 31 has a plurality of diodes D1, D2, a primary electronic sensing circuit LP, a first secondary electronic sensing circuit LS1, and a second secondary electronic sensing circuit LS2. The plurality of diodes D1, D2 are electrically connected to the first secondary electronic sensing circuit LS1 and the second secondary electronic sensing circuit LS2, respectively; a switching device 33 electrically connected to the power factor correcting inductor The electronic sensing device 32 is configured to selectively establish an electrical connection according to a control signal; a driving circuit 34 is coupled to the switching device 33 for generating the control signal according to an indication signal; a light source module 39, The light source module 39 is electrically connected to the secondary side of the electronic sensing device. The light source module 39 has a light emitting diode D4, and a feedback stage 35. The feedback stage 35 is electrically connected to the light source module. 39, configured to perform a comparison of an output voltage with a predetermined voltage and a comparison of an output current with a predetermined current to generate the indication signal; an output inductor 36 electrically coupled to the first secondary electronic induction The circuit LS1 is configured to suppress or store the energy output by the first secondary electronic induction circuit LS1; an output storage capacitor 37 electrically connected to the secondary side of the electronic sensing device 32, The output voltage of the stage side is stable; an input storage capacitor 38 is electrically connected to the primary electronic sensing circuit LP to store or release energy passing through the primary electronic sensing circuit LP.

Since the general light-emitting diode is quite sensitive to the operating voltage and the operating current, in the circuit of the general light source system, constant voltage control and current limiting control must be provided, and the voltage and current output to the light-emitting diode are controlled in the light. The working voltage and the operating current range that the diode can withstand; therefore, as shown in FIG. 11 , the feedback stage 35 is electrically connected to the light source module 39 for detecting the output to the light emitting diode The voltage and current in D4 make the feedback stage 35 compare its output current and output voltage. The range of the light-emitting diode D4 can be received, and the indication signal control is sent to the switch device 33 to prevent the light-emitting diode D4 from being able to withstand the output current and the output voltage and burned.

The above is only a preferred embodiment for explaining the present invention, and is not intended to limit the present invention in any way, and any modifications or alterations to the present invention made in the spirit of the same invention are still It should be included in the scope of the intention of the present invention.

2‧‧‧Single-stage high-power return-forward converter

21‧‧‧Power factor correction inductor

22‧‧‧Electronic sensing device

23‧‧‧Switching device

24‧‧‧Drive Circuit

25‧‧‧Feedback circuit

26‧‧‧Output inductance

27‧‧‧ Output storage capacitor

28‧‧‧Input storage capacitor

Vin‧‧‧Input voltage

Vout‧‧‧ output voltage

LP‧‧‧Primary electronic sensing circuit

LS1‧‧‧First secondary electronic sensing circuit

LS2‧‧‧Second secondary electronic sensing circuit

D1‧‧‧ diode

D2‧‧‧ diode

Claims (25)

A single-stage high-power-return-forward converter includes: a power factor correction inductor located at an input of the single-stage high-power return-forward converter; an electronic induction a device, the electronic sensing device is coupled to the power factor correction inductor, the electronic sensing device has a plurality of diodes, a primary electronic sensing circuit, a first secondary electronic sensing circuit, and a second secondary electronic sensing a circuit, the plurality of diodes are electrically connected to the first secondary electronic sensing circuit and the second secondary electronic sensing circuit, respectively; a switching device electrically connected to the power factor correction inductor and the electronic sensing device The driving circuit is connected to the switching device for generating the control signal according to an indication signal; and a feedback stage, the feedback stage is electrically connected to the driving circuit. The driving circuit is connected to the switching device for generating the control signal according to an indication signal. The secondary side of the electronic sensing device is configured to perform an comparison between an output voltage and a predetermined voltage to generate the indication signal; an output inductor, the output inductor is electrically connected The first secondary electronic sensing circuit is configured to suppress or store energy output by the first secondary electronic sensing circuit; an output storage capacitor electrically connected to the secondary side of the electronic sensing device The output voltage of the secondary side is stabilized; an input storage capacitor is electrically connected to the primary electronic sensing circuit to store or release energy passing through the primary electronic sensing circuit. The single-stage high-efficiency flyback-forward converter according to the first aspect of the patent application, wherein the driving circuit is a current mode controlled Pulse Width Modulation (PWM) control loop. The single-stage high-power-return-forward converter according to the second aspect of the patent application, wherein the current mode control pulse width modulation control loop is a current mode controlled pulse width modulation integrated body Circuit. A single-stage high power factor return-forward converter as described in claim 1 wherein the switching device is a transistor switch. The single-stage high-power-return-forward converter according to the first aspect of the patent application, wherein the first secondary electronic induction circuit is a center-tapped coil. The single-stage high-power-return-forward converter according to the first aspect of the patent application, wherein the electronic sensing device is coupled with an auxiliary sensing circuit for zero current detection. The single-stage high-power-return-forward converter according to the sixth aspect of the patent application, wherein the auxiliary sensing circuit is coupled to a Zero Current Detecting Circuit (ZCD Circuit). The single-stage high-power-return-forward converter according to the first aspect of the patent application, wherein the first secondary electronic sensing circuit and the second secondary sensing circuit are added with a diode, and can be added The output power is 50% to the output capacitor. A single-stage high-power-return-forward converter as described in claim 8 wherein the electronic sensing device is coupled to an auxiliary sensing circuit. The single-stage high-power-return-forward converter according to the ninth aspect of the patent application, wherein the output inductor is coupled to an output inductor sensing circuit. The single-stage high-power-return-forward converter according to the tenth aspect of the patent application, wherein the auxiliary sensing circuit and the output inductor sensing circuit are coupled to a zero current detecting circuit. The single-stage high-power-return-forward converter according to the first aspect of the patent application, wherein the primary electronic induction circuit and the switching device are coupled to a primary leakage inductance energy recovery circuit. The single-stage high-power-return-forward converter according to the first application of the patent application scope has a current sensing resistor connected in series below the switch, and then the current sensing resistor is amplified by a signal amplifying circuit. A light source system with a single-stage high-power return-forward converter, comprising: a power factor correction inductor, the power factor correction inductor is located in the single-stage high-power return-forward converter The input end; an electronic sensing device electrically connected to the power factor correction inductor, the electronic sensing device having a plurality of diodes, a primary electronic sensing circuit, and a first secondary electronic sensing circuit And a second secondary electronic sensing circuit, the plurality of diodes are electrically connected to the first secondary electronic sensing circuit and the second secondary electronic sensing circuit, respectively; a switching device electrically connected to the power a factor correction inductor and the electronic sensing device for selectively establishing an electrical connection according to a control signal; a driving circuit connected to the switching device for generating the control signal according to an indication signal; a light source a module, the light source module is electrically connected to a secondary side of the electronic sensing device, the light source module has a light emitting diode; a feedback stage, the The feedback stage is electrically connected to the light source module, configured to perform a comparison of an output voltage with a predetermined voltage and a comparison of an output current with a predetermined current to generate the indication signal; An output inductor electrically connected to the first secondary electronic sensing circuit for suppressing or storing energy output by the first secondary electronic sensing circuit; an output storage capacitor, the output storage capacitor being electrically connected And on the secondary side of the electronic sensing device, the output voltage of the secondary side is stabilized; an input storage capacitor is electrically connected to the primary electronic sensing circuit to store or release energy passing through the primary electronic sensing circuit An auxiliary sensing circuit detects the zero current of the output inductor and sends a zero current signal. A single-stage high-power-return-forward converter light source system as described in claim 14 wherein the drive circuit is a current mode controlled pulse width modulation (PWM) Control loop. A light source system with a single-stage high-power-return-forward converter as described in claim 14 of the patent application, wherein the current mode control pulse width modulation control loop is a current mode controlled pulse width Modulate the integrated circuit. A light source system having a single-stage high-power return-forward converter as described in claim 14 of the patent application, wherein the switching device is a transistor switch. A light source system having a single-stage high power factor return-forward converter as described in claim 14 wherein the first secondary electronic induction circuit is a center tap coil. A light source system having a single-stage high-power-return-forward converter as described in claim 14 wherein the electronic sensing device is coupled to an auxiliary sensing circuit. A light source system with a single-stage high-power-return-forward converter as described in claim 19, wherein the auxiliary sensing circuit is coupled to a zero current detecting circuit. A light source system with a single-stage high-power-return-forward converter as described in claim 14 of the patent application, wherein the first secondary electronic induction circuit is provided with a diode. The light source system of the single-stage high-power-return-forward converter according to the fourth aspect of the patent application, wherein the output inductor is coupled to an output inductor sensing circuit, and the sensing circuit is configured to detect the output inductor Zero current and send a zero current signal. The light source system of the single-stage high-power-return-forward converter, as described in claim 22, wherein the auxiliary induction circuit and the output inductor sensing circuit are coupled to a zero current detecting circuit. The light source system of the single-stage high-power-return-forward converter according to the fourteenth aspect of the patent application, wherein the primary electronic induction circuit and the switching device are coupled to a primary leakage inductance energy recovery circuit. The light source system of the single-stage high-power-return-forward converter, as described in claim 14 of the patent application, utilizes the output inductor zero current detection signal and the zero current detection signal of the auxiliary induction circuit, respectively, a weight, when the output inductor zero current detection signal drops to zero, the valley of the zero current detection signal of the auxiliary sensing circuit can be detected, and the switching device is turned on at the bottom of the valley, wherein the auxiliary sensing circuit is Detecting the zero current of the output inductor and sending a zero current signal.