TWI659597B - Power supply apparatus - Google Patents

Abstract

A power supply device for driving a light-emitting device. The power supply device includes a lossless vibration damping circuit and a power conversion circuit. The lossless vibration damping circuit has a first diode, a first inductor, and a second diode coupled in series between the input terminal and the first reference terminal, and has a first capacitor coupled between the first diode and the first diode. Between the two reference ends. The power conversion circuit includes a switch, a transformer, and a second inductor. The switch is coupled between the first reference terminal and the second reference terminal, and is turned on or off according to a control signal. The second inductor is coupled in parallel with the primary side of the transformer.

Description

Power supply device

The present invention relates to a power supply device, and more particularly, to a power supply device for driving a light-emitting device.

With the evolution of light emitting diode (LED) technology, it has become a trend to apply high-power light emitting diodes to construct high-brightness light-emitting devices (such as street lamps). According to statistics, in 2005 AD, global street lamps (including street lamps) consumed a total of 114 TWh of energy. Based on this estimate, there are about 130 million street lights worldwide. In addition, the number of global street lamps is growing year by year. Taking 2010 as an example, the global street lamp market size is about 160 to 180 million, and it is increasing with an annual growth rate of 20%.

On the other hand, as the issue of global warming gradually heats up, energy conservation and carbon reduction are important requirements for electronic devices. Therefore, it is an important issue for designers in the field to provide a high-efficiency power supply device for driving street lamps.

The invention provides a power supply device, which can have the effect of power factor correction.

The power supply device of the present invention is used to drive a light-emitting device. The power supply device includes a lossless vibration damping circuit and a power conversion circuit. The lossless vibration damping circuit has a first diode, a first inductor, and a second diode coupled in series between the input terminal and the first reference terminal, and has a first capacitor coupled between the first diode and the first Between the two reference terminals, the input terminal receives input power. The power conversion circuit includes a switch, a transformer, and a second inductor. The switch is coupled between the first reference terminal and the second reference terminal, and is turned on or off according to a control signal. The primary side of the transformer is coupled between the input terminal and the second reference terminal, and the secondary side of the transformer is coupled between the output terminal and the third reference terminal. The second inductor is coupled in parallel with the primary side of the transformer.

In an embodiment of the invention, the power supply device further includes a third diode. The third diode is coupled between the secondary side of the transformer and the output terminal.

In an embodiment of the present invention, the switch is turned on in the first time interval, the input terminal provides input power to make the current on the second inductor rise linearly, the first capacitor transmits power to the first inductor, and the second two The polar body is turned on, and the first diode and the third diode are turned off.

In an embodiment of the present invention, the switch is turned off in a second time interval after the first time interval, so that the first diode, the second diode, and the third diode are turned on, so that the first diode is turned on. The two inductors provide power to the output through the transformer, and the current on the second inductor decreases linearly.

In an embodiment of the present invention, during the second time interval, the power on the first inductor is transmitted to the input terminal.

In an embodiment of the present invention, the In the third time interval, the first diode and the second diode are turned off, and the second inductor transmits power to the output terminal through the transformer.

In an embodiment of the present invention, the anode of the first diode is coupled to the input terminal, the cathode of the first diode is coupled to the first terminal of the first inductor, and the second terminal of the first inductor is coupled Connected to the anode of the second diode, the cathode of the second diode is coupled to the first reference terminal, and the first capacitor is coupled between the cathode of the first diode and the second reference terminal.

In an embodiment of the invention, the power supply device further includes a third inductor. The third inductor is coupled between the second inductor and the anode of the first diode.

In an embodiment of the invention, the power supply device further includes an input capacitor and an output capacitor. The input capacitor is coupled between the input terminal and the first reference terminal. The output capacitor is coupled between the output terminal and the third reference terminal.

In an embodiment of the invention, the power supply device further includes a control signal generator. The control signal generator is coupled to the switch, the output terminal, the input terminal, and the transformer. The control signal generator obtains a plurality of feedback signals according to the voltage signals and / or current signals detected on the output terminal, the input terminal, and the transformer, and generates the control signals according to the feedback signals.

In an embodiment of the present invention, the control signal generator includes an AC input voltage detection circuit, an inductor current detection circuit, an output voltage and current feedback circuit, and a pulse width modulation signal generator. The AC input voltage detection circuit is coupled to the input terminal, and generates a first feedback signal according to the voltage on the input terminal. The inductor current detection circuit is coupled to the transformer, and generates a second feedback signal according to the voltage on the transformer. The output voltage and current feedback circuit is coupled to the output terminal. And the current generates a third feedback signal. The pulse width modulation signal generator is coupled to an AC input voltage detection circuit, an inductor current detection circuit, and an output voltage and current feedback circuit. control signal.

In an embodiment of the present invention, the control signal generator further includes an optical coupler. The photocoupler is coupled to the output voltage and current feedback circuit and the pulse width modulation signal generator. The optical coupler transmits the third feedback signal to the pulse width modulation signal generator through the optical coupling method.

In an embodiment of the present invention, the source supply device further includes a filter and a bridge rectifier. The filter receives AC power and filters the AC power. The bridge rectifier is coupled to the filter, rectifies the AC power and generates an input power.

Based on the above, the power supply device provided by the present invention can design the transformer's magnetizing inductance (second inductance) in a discontinuous conduction mode (Discontinuous-Conduction Mode, DCM), and can have a function of power factor correction. In addition, the power supply device of the present invention can achieve the effect of high power factor by designing the current of the magnetizing inductance (the second inductance) to operate in the boundary conduction mode, and by controlling the on and off times of the switch.

In order to make the above features and advantages of the present invention more comprehensible, embodiments are hereinafter described in detail with reference to the accompanying drawings.

100, 300, 500‧‧‧ power supply units

101, 301, 501‧‧‧ light-emitting devices

110, 310, 510‧‧‧‧Lossless damping circuit

120, 320, 520‧‧‧ Power Conversion Circuit

330‧‧‧Filter

340‧‧‧bridge rectifier

550‧‧‧Control signal generator

551‧‧‧AC input voltage detection circuit

556‧‧‧Inductive current detection circuit

554‧‧‧Output voltage and current feedback circuit

552‧‧‧ Pulse Width Modulation Signal Generator

553‧‧‧ Optocoupler

D ₁ ~ D ₇ ‧‧‧ Diode

L _B 、 L _m 、 L _sn 、 L _lk 、 L _f ‧‧‧Inductance

C _DC 、 C _f 、 C _sn ‧‧‧Capacitor

RE1, RE2, RE3‧‧‧ reference terminal

INE‧‧‧input

OUE‧‧‧ output

SW1‧‧‧Switch

T ₁ ‧‧‧Transformer

n _P ‧‧‧ primary side

n _n ‧‧‧ secondary side

C _o ‧‧‧ output capacitor

C _in ‧‧‧ input capacitor

VIN‧‧‧ input power

i _Lm , i _LB ‧‧‧ current

R _O ‧‧‧ resistance

FIG. 1 is a schematic diagram of a power supply device according to an embodiment of the invention.

FIG. 2A to FIG. 2D are isoelectric circuit diagrams showing the operating state of the power supply device.

FIG. 3 is a schematic diagram of a power supply device according to another embodiment of the invention.

FIG. 4A to FIG. 4D are isoelectric circuit diagrams showing the operating state of the power supply device.

FIG. 5 is a schematic diagram of a power supply device according to still another embodiment of the present invention.

Please refer to FIG. 1, which is a schematic diagram of a power supply device according to an embodiment of the present invention. The power supply device 100 includes a lossless vibration damping circuit 110 and a power conversion circuit 120. The lossless vibration damping circuit 110 includes diodes D ₅ , D ₆ , an inductor L _B, and a capacitor C _DC . Among them, the diode D ₆ , the inductor L _B and the diode D _{5 are} connected in series between the input terminal INE and the reference terminal RE1. For details, the anode of the diode D ₆ is coupled to the input terminal INE, and the cathode of the diode D ₆ is coupled to the first terminal of the inductor L _B. The second terminal of the inductor L _B is coupled to the anode of the diode D ₅ , and the cathode of the diode D ₅ is coupled to the reference terminal RE1. The capacitor C _{DC is} coupled between the cathode of the diode D ₆ and the reference terminal RE2.

On the other hand, in the present embodiment, the power conversion circuit 120 includes a switch SW1, inductor L _m and a transformer T _1. The switch SW1 may be constructed by a power transistor and coupled between the reference terminal RE1 and the reference terminal RE2. The switch SW1 is controlled by the control signal S1 to be turned on or off. The transformer T ₁ has a primary side n _P and a secondary side n _n . The primary side n _{P of the} transformer T ₁ is coupled between the input terminal INE and the reference terminal RE ₂ , and the secondary side n _{n of the} transformer T ₁ is coupled to the output terminal. Between OUE and RE3. The inductance L _m is coupled in parallel with the primary side n _{P of the} transformer T ₁ .

In addition, the power conversion circuit 120 includes a diode D ₇ and an output capacitor _Co. The anode of the diode D ₇ is coupled to the secondary side n _n of the transformer T ₁ , and the cathode of the diode D ₇ is coupled to Output OUE. The output capacitor C _o is connected in series between the output terminal and the reference terminal OUE RE3. Among them, the reference terminal RE2 can be used as the reference ground terminal of the primary side n _P of T ₁ , and the reference terminal RE3 can be used as the reference ground terminal of the secondary side n _n of T ₁ .

For details of the operation of the power supply device 100, please refer to the isochronous circuit diagram of the operation state of the power supply device shown in FIGS. 2A to 2D. In FIG. 2A, the power supply device 100 is operated in a first time period, wherein the switch SW1 is turned on according to the control signal S ₁ , the diode D _{5 is} turned on, and the diodes D ₆ and D ₇ are in an off state. At the same time, the capacitor C _DC , the inductor L _B , the diode D ₅ and the switch SW1 form a loop. Capacitor C _DC electrical energy is transferred to the inductance L _B, the current i _LB on the linear increase and the inductance L _B. On the other hand, the inductor L _m , the input power source VIN, and the switch SW1 also form another loop, and according to the power provided by the input power source VIN, the current i _Lm on the inductor L _m increases linearly correspondingly.

On the other hand, the output capacitor _Co provides the stored electric energy to generate an output current I _O , and drives the light emitting device 101 through the output current I _{O to} make the light emitting device 101 emit light. The light emitting device 101 may be a street lamp constructed by a light emitting diode.

Please refer to FIG. 2B. In FIG. 2B, the power supply device 100 operates in a first stage of a second time period. At this time, the switch SW1 according to the control signal S ₁ is turned off, diode D _5, D ₆ and D ₇ are conducting state. Among them, the input power source VIN, the diode D ₆ , the inductor L _B and the diode D ₅ form a loop. At this time, the current i _LB of the inductance L _B as the damping inductance linearly decreases and returns to the energy input terminal INE. In addition, the inductor L _m , the diode D _6, and the capacitor C _DC form a second loop, and the current i _Lm of the inductor L _m as the magnetized inductor linearly decreases, and the power is transmitted to the output terminal OUE through the transformer T ₁ to drive the light.装置 101。 Device 101.

Please refer to FIG. 2C. In FIG. 2C, the power supply device 100 operates in the second stage of the second time period. At this time, the switch SW1 according to the control signals S ₁ continues to be turned off. Diode D ₅ is in an off state, and diodes D ₆ and D ₇ are both in an on state. At this time, the electric energy in the inductor L _B is released, the loop formed by the inductor L _m , the diode D ₆ and the capacitor C _DC continues to _operate , and the current i _{Lm of the} inductor L _m decreases linearly and is transmitted through the transformer T ₁ The electric energy is output to the output terminal OUE, and the light emitting device 101 is driven by the output current I _O.

Please refer to FIG. 2D. In FIG. 2D, the power supply device 100 operates in the third stage of the second time period. In this case, the switch SW1 according to the control signals S ₁ continues to be turned off, based on the energy of the inductance L _m is released is completed, diode D ₆ and D ₇ is turned off corresponds. At this time, the output capacitor _Co provides power to generate an output current I _O to drive the light emitting device 101. And, after this stage, the switch SW1 is turned on again to enter the next power supply cycle (first time period).

Through the three-phase-based and periodic actions of the first time period and the second time period described above, the power supply device 100 can continuously provide power to drive the light-emitting device 101. Through the function of the lossless vibration damping circuit 110, the voltage rising phenomenon on the switch SW1 generated when the switch SW1 is switched can be slowed down, thereby achieving the purpose of vibration damping. In addition, when the switch SW1 is turned off, the power on the capacitor C _DC can be recovered to the input terminal INE to reduce power consumption.

Please refer to FIG. 3 below, which illustrates a schematic diagram of a power supply device according to another embodiment of the present invention. The power supply device 300 is used to drive the light-emitting device 301. The power supply device 300 includes a lossless vibration damping circuit 310, a power conversion circuit 320, a filter 330, a bridge rectifier 340, an input capacitor _Cin , an output capacitor _Co, and a diode D7. The filter 330 is coupled to the AC power source V _AC and filters the AC power source V _AC . The bridge rectifier 340 is coupled to the filter 330 to rectify the AC power V _AC and generate an input power VIN. The filter 330 is a low-pass filter composed of an inductor L _f and a capacitor C _f . The bridge rectifier 340 is composed of diodes D ₁ to D ₄ . The input capacitor C _{in is} set between the input terminal INE and the reference terminal RE1 and receives the input power VIN. The lossless damping circuit 310 is coupled to the input terminal INE, and includes a diode D ₅ , an inductor L _sn and a diode D ₆ connected in series between the input terminal INE and the reference terminal RE1, and includes a coupling between the diode D ₆ and the diode D ₆ . The capacitance C _sn between the cathode terminal of the electrode body D ₅ and the transformer T ₁ .

The power conversion circuit 320 is coupled to the lossless damping circuit 310. The power conversion circuit 320 includes a switch SW1, an inductor L _lk , an inductor L _m, and a transformer T ₁ . Different from the foregoing embodiment, the power conversion circuit 320 of this embodiment includes an inductor L _lk , where the inductor L _{lk is} coupled between the input terminal INE and the transformer T ₁ and can be used as a leakage inductance.

For details of the operation of the power supply device 300, please refer to the isochronous circuit diagrams of the operation state of the power supply device shown in FIGS. 4A to 4D. In FIG. 4A, the power supply device operates in a first time period, wherein the switch SW1 according to the control signal S ₁ is turned on, diode D _5, diode D ₆ is turned on, while the diode D ₇ is in the off state. At the same time, the capacitor C _sn , the inductor L _sn , the diode D ₆ and the switch SW1 form a loop. The electric energy in the capacitor C _sn is transferred to the inductor L _sn , and the current on the inductor L _sn is increased linearly. On the other hand, the inductor L _m , the inductor L _lk , the input capacitor C _in and the switch SW1 also form another loop, and according to the power provided by the input power source VIN, the currents on the inductor L _m and the inductor L _lk increase linearly.

On the other hand, the output capacitor _Co provides the stored electric energy to generate an output current, drives the light emitting device 301 through the output current, and causes the light emitting device 301 to emit light. The light emitting device 301 may be a street lamp constructed by a light emitting diode.

Please refer to FIG. 4B. In FIG. 4B, the power supply device is operated in the first stage of the second time period. At this time, the switch SW1 according to the control signal S ₁ is turned off, diode D _5, D ₆ and D ₇ are conducting state. The input capacitor C _in , the diode D ₅ , the inductor L _sn, and the diode D ₆ form a loop. At this time, the current of the inductor L _sn as the damping inductor linearly decreases, and the electric energy is returned to the input capacitor C _in . In addition, the inductor L _lk , the diode D _5, and the capacitor C _sn form a second loop, and the current of the inductor L _lk as the leakage inductance linearly decreases, and the power is transmitted to the output terminal OUE through the transformer T ₁ to drive the light emitting device 301. . In addition, the inductance L _m and the primary side n _{P of the} transformer T ₁ form a third loop, and the current of the inductance L _m as the magnetizing inductance linearly decreases, and the electric energy is transmitted to the output terminal OUE through the transformer T ₁ to drive the light-emitting device 301.

Please refer to FIG. 4C. In FIG. 4C, the power supply device operates in the second stage of the second time period. At this time, the switch SW1 according to the control signals S ₁ continues to be turned off. Diodes D ₅ to D ₇ are all in an on state. At this time, the electric energy in the inductor L _lk is completely released, and the inductor L _m and the primary side n _{P of the} transformer T ₁ form a loop to continue to operate. The current of the inductance L _m as the magnetizing inductance decreases linearly, and the electric energy is transmitted to the output terminal OUE through the transformer T ₁ to drive the light emitting device 301. At the same time, the loop formed by the input capacitor C _in , the diode D ₅ , the inductor L _sn, and the diode D ₆ continues to operate, and the inductor L _sn continues to return energy to the input capacitor C _in .

Please refer to FIG. 4D. In FIG. 4D, the power supply device is operated in the third stage of the second time period. In this case, the switch SW1 according to the control signals S ₁ continues to be turned off, based on the energy of the inductance L _sn completed is released, the corresponding diode D ₅ is turned off. At this time, the inductor L _m and the primary side n _{P of the} transformer T ₁ form a loop to continuously operate, and the inductor L _m provides power through the transformer T ₁ to drive the light-emitting device 301. And, after this stage, the switch SW1 is turned on again to enter the next power supply cycle (first time period).

Through the three-phase-based and periodic actions of the first time period and the second time period described above, the power supply device 300 can continuously provide power to drive the light-emitting device 301. Through the function of the lossless vibration damping circuit 310, the voltage rising phenomenon on the switch SW1 generated when the switch SW1 is switched can be slowed down to achieve the purpose of vibration damping. In addition, when the switch SW1 is turned off, the power on the capacitor C _sn can be recovered to the input terminal INE to reduce power consumption.

Please refer to FIG. 5 below, which illustrates a schematic diagram of a power supply device according to still another embodiment of the present invention. The power supply device 500 includes a filter 530, a bridge rectifier 540, a lossless snubber circuit 510, a power conversion circuit 520, the input capacitance C _in, C _o and the output capacitance diode D _7. The power supply device 500 receives an AC power source V _AC and is used to drive the light emitting device 501. The circuit operation details of the power supply device 500 have been described in detail in the foregoing embodiments, and will not be repeated here.

Unlike the previous embodiment, the power supply device 500 further includes a control signal generator 550. A control signal generator 550 is coupled to the switch SW1, the output terminal OUE, INE and the transformer input terminals T _1. The control signal generator 550 obtains a plurality of feedback signals according to the voltage signals and / or current signals on the detection output terminal OUE, the input terminal INE, and the transformer T ₁ . The control signal generator 550 generates a control signal S ₁ according to the feedback signal described above.

In this embodiment, the control signal generator 550 includes an AC input voltage detection circuit 551, an inductor current detection circuit 556, an output voltage and current feedback circuit 554, a pulse width modulation signal generator 552, and an optical coupler 553. The AC input voltage detection circuit 551 is coupled to the input terminal INE, and generates a first feedback signal according to the voltage on the input terminal INE. The inductor current detection circuit 556 is coupled to the transformer T ₁ and generates a second feedback signal according to the voltage on the transformer T ₁ . The output voltage and current feedback circuit 554 is coupled to the output terminal OUE, and generates a third feedback signal according to the voltage and current on the output terminal OUE. The PWM signal generator 552 is coupled to the AC input voltage detection circuit 551, the inductor current detection circuit 556, and the output voltage and current feedback circuit 554. According to the first feedback signal, the second feedback signal, and the third feedback Signal to generate a control signal S ₁ .

Incidentally, the primary and secondary sides of the transformer T ₁ have different reference terminals RE2 and RE3 respectively. Therefore, in the control signal generator 550, the PWM signal generator 552 and the output voltage and current feedback can be feedbacked. An optical coupler 553 is provided between the circuits 554. The optical coupler 553 transmits the third feedback signal to the pulse width modulation signal generator 552 through the optical coupling method.

In addition, in order to detect the current on the light emitting device 501, a resistor R _O may be connected in series with the reference terminal RE3 in the light emitting device 501. By measuring the voltage difference between the resistor R _O and the reference terminal RE3, the magnitude of the current on the light emitting device 501 can be known.

In the embodiment of the present invention, by designing the current of the inductor L _m to operate in the boundary conduction mode, the signals fed back by the AC input voltage detection circuit 551 and the inductor current detection circuit 556 are sent to a pulse having a multiplier function. The wide modulation signal generator 552 can make the current signal at the input terminal INE track the voltage of the AC input power supply V _AC , and can achieve the effect of high power factor. In addition, the output voltage and current feedback circuit 550 can detect the voltage and current signals of the light-emitting device 501, and send them to the pulse width modulation signal generator 552 with a multiplier function through the optical coupler 553, and change the switch by this. The switching frequency of SW1 can control the output voltage and output current of the light-emitting device 501.

In summary, the present invention can effectively recover the input power and save power consumption through the cooperation of the lossless vibration damping circuit and the power conversion circuit. In addition, by designing and operating the transformer's magnetized inductance (second inductance) in the discontinuous conduction mode, it can have the function of power factor correction, and by controlling the time when the switch is turned on and off, it can achieve a high power factor .

Although the present invention has been disclosed as above with the examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims (13)

A power supply device for driving a light-emitting device includes a lossless vibration damping circuit having a first diode, a first inductor, and a first diode coupled in series between an input terminal and a first reference terminal. A second diode having a first capacitor coupled between the first diode and a second reference terminal, wherein the input terminal receives an input power source; and a power conversion circuit including: a switch, a coupling Is connected between the first reference terminal and a second reference terminal, and is turned on or off according to a control signal; a transformer, the negative terminal of the primary side is coupled to the input terminal and the positive terminal is coupled to the second reference terminal The secondary side of the transformer is coupled between an output terminal and a third reference terminal; and a second inductor is coupled in parallel with the primary side of the transformer. The power supply device according to item 1 of the scope of patent application, further comprising: a third diode, coupled between the secondary side of the transformer and the output terminal. The power supply device according to item 2 of the scope of patent application, wherein the switch is turned on in a first time interval, the input terminal provides the input power to make the current on the second inductor rise linearly, and the first capacitor transmits The electric energy reaches the first inductor, and the second diode is turned on, and the first diode and the third diode are turned off. The power supply device according to item 3 of the scope of patent application, wherein the switch is turned off a second time interval after the first time interval, so that the first diode, the second diode, and The third diode is turned on, so that the second inductor provides power to the output terminal through the transformer, and the current on the second inductor decreases linearly. The power supply device according to item 4 of the scope of patent application, wherein in the second time interval, the power on the first inductor is transmitted to the input terminal. The power supply device according to item 4 of the scope of patent application, wherein in a third time interval after the second time interval, the first diode and the second diode are turned off, and the second inductor is turned off. Power is transmitted to the output terminal through the transformer. The power supply device according to item 1 of the scope of patent application, wherein the anode of the first diode is coupled to the input terminal, the cathode of the first diode is coupled to the first terminal of the first inductor, The second terminal of the first inductor is coupled to the anode of the second diode, the cathode of the second diode is coupled to the first reference terminal, and the first capacitor is coupled to the first diode. Between the cathode and the second reference terminal. The power supply device according to item 1 of the patent application scope further includes a third inductor coupled between the second inductor and the anode of the first diode. The power supply device according to item 1 of the patent application scope further includes: an input capacitor coupled between the input terminal and the first reference terminal; and an output capacitor coupled between the output terminal and the third Between reference ends. The power supply device according to item 1 of the scope of patent application, further comprising: a control signal generator coupled to the switch, the output terminal, the input terminal, and the transformer, and the output terminal and the input terminal are detected based on the detection. And the voltage signal and / or current signal on the transformer to obtain a plurality of feedback signals respectively, and generate the control signal according to the feedback signals. The power supply device according to item 10 of the patent application scope, wherein the control signal generator includes: an AC input voltage detection circuit coupled to the input terminal to generate a first circuit based on the voltage on the input terminal. An inductive current detection circuit coupled to the transformer to generate a second feedback signal based on the voltage on the transformer; an output voltage and current feedback circuit coupled to the output terminal according to the output A voltage and current on the terminal generates a third feedback signal; and a pulse width modulation signal generator coupled to the AC input voltage detection circuit, the inductor current detection circuit, and the output voltage and current feedback circuit, The control signal is generated according to the first feedback signal, the second feedback signal, and the third feedback signal. The power supply device according to item 11 of the scope of patent application, wherein the control signal generator further comprises: an optical coupler coupled to the output voltage and current feedback circuit and the pulse width modulation signal generator. In the optical coupling mode, the third feedback signal is transmitted to the pulse width modulation signal generator. The power supply device according to item 1 of the patent application scope further includes: a filter that receives an AC power source and filters the AC power source; and a bridge rectifier that is coupled to the filter and targets the AC power source Rectify and generate this input power.