KR20190054992A - Low-voltage DC-DC Converter AND BATTERY CHARGER - Google Patents

Abstract

The present invention relates to a low-voltage DC-DC converter which is a noise-free, and a battery charger. The low-voltage DC-DC converter comprises: a gate driver unit including a gate driver IC and an LLC resonant converter to which a gallium nitride high electron mobility transistor is applied; a resonant driver unit including an LLC resonant driver IC; and a rectifying unit including a secondary side synchronous rectifier and a driver IC.

Description

TECHNICAL FIELD [0001] The present invention relates to a low-voltage DC-DC converter and a battery charger,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter or a battery charger used for charging a battery of an electric vehicle or an electric motorcycle, and more particularly, to a low-voltage DC-DC converter Using the new material GaN-HEMT, the high efficiency is maintained even at low voltage, and the switching characteristic is improved and the switching loss is small.

In the situation where the electric vehicle is commercialized and running on the road, it is necessary to respond to the maintenance situation. In particular, companies are aiming to miniaturize and optimize Switching Mode Power Supply (SMPS), one of the key components, to facilitate immediate replacement in the event of maintenance. In this case, switching devices such as IGBTs and MOSFETs have been used in consideration of design cost, but a heat sink is essential while increasing the switching frequency and considering the breakdown voltage, but the influence on the overall unit price (MC) is significant.

LLC resonant converter (LLC resonant converter) is capable of ZVS (Zero Voltage Switching) under all load conditions and has a simple structure. Therefore, LLC resonant converter can be used in various SMPS design fields from small capacity to large capacity It is the attractive topology that is being used. However, there is still a limit to achieving the high efficiency of the power supply required by the enterprise and miniaturization of the PCB circuit.

Low-voltage DC-DC converters (LDCs) used in environmentally friendly vehicles are an important component for charging low-voltage auxiliary batteries that supply power to in-vehicle electrical systems from high voltages. However, it is difficult to maintain high efficiency at low voltage, large loss voltage at switching, and sudden decrease in load current.

Korean Patent Registration No. 10-1287803, LLC Synchronous Rectifier Drive Circuit for Resonant Half-Bridge Converter and Driving Method Thereof Korean Patent Registration No. 10-1286509, a battery charger using a series resonant converter

In order to solve the above-mentioned problems, the present invention can minimize the size of the LLC resonant converter by varying the resonance frequency by applying GaN HEMT (Gallium Nitride High Electron Mobility Transistor).

In the present invention, a synchronous rectification (SR) LLC topology circuit is added to the secondary side instead of a diode to satisfy both of the increase in efficiency and the temperature characteristic.

The present invention provides a converter capable of varying in various capacities by hiding the gate control circuit of the LLC controller and the SR driver of the synchronous rectification stage.

 The present invention makes it possible to vary the frequency of the concealed control circuit to diversify the capacity and efficiency.

A low voltage DC converter according to an embodiment of the present invention includes a gate driver unit including a gate driver IC and an LLC resonant converter to which a gallium nitride high electron mobility transistor is applied; A resonant driver section including an LLC resonant driver IC; And a rectifying section including a secondary side synchronous rectifier and a driver IC.

In the low voltage DC converter according to an embodiment of the present invention, the gate driver IC can be operated at a switching frequency ranging from 400 KHz to 1 MHz.

In the low-voltage DC converter according to the embodiment of the present invention, the driver IC of the rectifier may be a dedicated driver IC operating at a switching frequency of 400 KHz or more.

A battery charger according to an embodiment of the present invention includes an input unit for performing a protection function for a primary side circuit; And a boost converter portion for maintaining an input current to the AC power supply and providing an inrush current path to the capacitor to prevent resonant interaction between the switching inductor and the output capacitor.

The battery charger according to an exemplary embodiment of the present invention further includes an output filter and a storage unit for storing energy for power factor correction (PFC) output.

A battery charger according to an embodiment of the present invention includes a DC direct current converter unit having an output terminal operated to be a constant voltage or a constant current; A voltage current controller for controlling at least one of an output voltage and an output voltage using a sensing resistor at an output terminal; And a rectification section for rectifying the voltage and current and removing the noise.

In the battery charger according to an embodiment of the present invention, the DC direct converter section operates as a control circuit required for the forward converter and the flyback standby converter.

The battery charger according to an embodiment of the present invention includes at least one of the transistor, the capacitor, and the inductor.

A battery charger according to an embodiment of the present invention includes an input unit including a high line input flyback power supply of 59V / 120W and a secondary control circuit; And a fly-back battery charger supply and includes an on-board charging unit.

The battery charger according to an embodiment of the present invention is characterized in that the charging unit 163 includes an operational amplifier LM358D to charge the battery while sensing the state of the battery and to control the output based on the output current or reference to the output voltage do.

According to the present invention, it is possible to provide a low-voltage DC converter in which voltage and current are rectified and noise is removed.

According to the present invention, a GaN HEMT is used and a SR LLC topology circuit is added to the secondary side in place of a diode to obtain high efficiency and miniaturization, and both efficiency and temperature characteristics can be satisfied.

According to the present invention, a concealment circuit is formed in the gate driver of the resonance circuit portion and the synchronous rectification portion so that the frequency can be freely adjusted.

1 illustrates an LLC resonant converter circuit according to the present invention.
FIG. 2A illustrates a power factor controller (PFC) circuit according to the present invention.
2B illustrates a gate drive circuit of a power factor controller according to the present invention.
FIGS. 3A and 3B are diagrams illustrating a reverse conduction state of a transistor according to an exemplary embodiment of the present invention. Referring to FIG.
FIG. 3C is a diagram illustrating a reverse recovery time of a transistor according to an embodiment of the present invention. FIG.
FIG. 4 shows waveforms in the reverse recovery of a high electron mobility transistor and a MOSFET in accordance with an embodiment of the present invention.
Figure 5 shows the measured values for another switch speed IF = 0 A, in accordance with an embodiment of the present invention.
FIG. 6 is a diagram comparing a typical LLC converter and a demo board using a gallium nitride high electron mobility transistor according to an embodiment of the present invention.
FIG. 7 shows waveforms of a general power factor controller according to an embodiment of the present invention, and FIG. 8 shows waveforms at soft-start and brown-out according to an embodiment of the present invention. 9 is a graph illustrating Vdc waveform Volt, current waveform, and rising polling time according to an embodiment of the present invention.
FIG. 10 is a result of checking the heating characteristics of the main parts in the embodiment of the present invention.
11 shows a control circuit applied to an LLC control gate according to an embodiment of the present invention.
12 shows a control circuit applied to the gate of the resonance rectifier control unit according to an embodiment of the present invention.
13 shows a circuit diagram and operation waveform of a low-voltage DC converter applied to an electric vehicle according to an embodiment of the present invention.
Figure 14 shows a circuit diagram and operational waveform of a battery charger according to an embodiment of the present invention.
15 shows a circuit diagram and operational waveform of a battery charger applied to an electric wheelchair or electric scooter according to an embodiment of the present invention.
16 shows a circuit diagram and operational waveform of a battery charger applied to an electric motorcycle according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of attaining them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. To fully disclose the scope of the invention to a person skilled in the art, and the invention is only defined by the scope of the claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. For example, an element expressed in singular < Desc / Clms Page number 5 > terms should be understood to include a plurality of elements unless the context clearly dictates a singular value. In addition, in the specification of the present invention, it is to be understood that terms such as "include" or "have" are intended to specify the presence of stated features, integers, steps, operations, components, The use of the term does not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, parts or combinations thereof.

As used herein, the term " module " or " module " means a functional part that performs at least one function or operation, and may be implemented in hardware or software or a combination of hardware and software. In addition, a plurality of 'modules' or a plurality of 'parts' may be integrated into at least one module except for 'module' or 'module' which needs to be implemented by specific hardware, and may be implemented by at least one processor.

In addition, all terms used herein, including technical or scientific terms, unless otherwise defined, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be construed as meaning consistent with meaning in the context of the related art and may be interpreted in an ideal or overly formal sense unless explicitly defined in the specification of the present invention It does not.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions will not be described in detail if they obscure the subject matter of the present invention.

1 illustrates an LLC resonant converter circuit according to an embodiment of the present invention. Referring to FIG. 1, the LLC resonant converter includes an input power supply 140 for supplying an input voltage, a transformer for converting a resonance voltage to a voltage of a predetermined level according to a winding ratio to generate a secondary side voltage, Tr), and a synchronous rectifier 110 installed in the secondary winding to rectify the secondary voltage transmitted through the transformer Tr to a DC voltage.

The input power supply unit 140 may include an AC input voltage (AC), an EMI filter, and a bridge diode, and may filter and rectify the input AC input voltage.

The voltage rectified by the input power supply unit 140 is applied to the capacitor Cin and is transmitted to the resonance circuit unit 150 so that the frequency characteristic is changed and converted into a resonance voltage of a predetermined level to be transmitted to the primary winding of the transformer Tr . The resonant circuit portion 150 may include at least one gallium nitride high electron mobility transistor 130. In FIG. 1, the transistors Q1, Q2, and Q3 may be gallium nitride high electron mobility transistors.

The synchronous rectification part 110 may include at least one switching element SR1 or SR2 and the switching element may be a synchronous rectifier.

A synchronous rectification topology, that is, a synchronous rectification section 110 and a GA-N high electron mobility transistor 130 may be applied as a typical boost-based converter 100 circuit. If the transistors Q1, Q2, and Q3 are formed of a conventional silicon MOSFET (Si MOSFET), there is a limitation in the switching frequency in the system implementation, and the device becomes large, and there is a space restriction in the circuit design. Further, the leakage inductance of the primary winding of the transformer Tr and the self-parallel-parallel resonance tank are formed by the capacitor C1. In this way, the voltage distribution acts from the resonant tank and the secondary side load. By changing the frequency of the input voltage (Ac), the impedance change of the resonant tank becomes inevitable, and the impedance divides the load input voltage. The secondary winding transistors SR1 and SR2 of the transformer may employ a synchronous rectification (SR) scheme to improve the output performance and efficiency.

2A illustrates a power factor controller (PFC) circuit. When a typical power factor controller is driven, parasitic inductance and parasitic capacitance are observed. These parasitic components can be excited by voltage and current when switching and forming a high frequency resonance circuit. According to the present invention, gallium nitride high electron mobility transistors can be used to prevent excessive ringing in power circuit design.

Figure 2B illustrates the gate drive circuit of the power factor controller. As shown in FIG. 2B, the parasitic inductance and the parasitic capacitance are generated. When the parasitic inductance is too large, the induced voltage may affect the gate drive voltage. A gallium nitride high electron mobility transistor is applied to minimize this effect.

FIGS. 3A and 3B are schematic diagrams of a transistor in a reverse conduction state. FIG. When the gallium nitride high electron mobility transistor 320 is switched off, a reverse voltage is applied to the switch of the transistor 320 so that the current flows to the diode 311 and the transistor 320 of the transistor 310. During the reverse conduction, a voltage drop through the internal diode voltage drop VSD-SI occurs when the reverse voltage drops through the VSD switch of the transistor 320.

Equation 1: VSD = VSD - SI + IF * RDS (ON) - GaN

Is represented by a function similar to the reverse voltage drop of the switch to the transistor 320 as shown in Equation (1), and is higher than the internal diode voltage drop.

Can be reduced by operating the low-voltage silicon in reverse voltage drop reverse conduction to improve the performance of the application to be applied. This phenomenon is completed in normal turn-off. On the other hand, as shown in FIG. 3B, the threshold voltage Vt of the high electron mobility transistor 320 is lower than that of the silicon transistor 310 by applying a gate voltage (Vgs> 4V).

FIG. 3C is a schematic diagram of a transistor in a reverse turn off (reverse recovery). The high electron mobility transistor 340 exhibits a relatively small reverse recovery loss in the switch. 3C, the inductor 350 and the control switch Q1 are turned on and the current is determined by the control switch Q1 and the inductor 350. [

Fig. 4 shows waveforms in the reverse recovery of a high electron mobility transistor and a MOSFET. Both tests were conducted at the initial test time of 9A / 400V and were higher than conventional reverse bias voltage and stable. Also, the recovery charge (Qrr) is 25 times higher than the existing MOSFET.

Table 1 below compares the specifications of the Cool MOSFET (IPP60R38C6) with the gallium nitride high electron mobility transistor (TPH3002PS), and the recovery charge (Qrr) helps to reduce spikes at the start of the DC-DC converter.

parameter TPH3002PS IPP60R38C6 ID 9A (continuous) 9A (for D = 0.75) Ron 290mΩ 340mΩ Qg 6.2 nC 32nC Eoss (400V) 3.1 μJ 2.8 μJ Qrr 29nC 3.3 μC

Switches in gallium nitride high electron mobility transistors operate in three modes including forward, forward conduction, and shutoff, and switching in reverse conduction is very fast and superior to MOSFET.

Figure 5 shows a graph of the measured value for another switch speed IF = 0A. Which constitutes about 86% of the total recovery charge. Qc is measured to be 35 nC. In other words, restoration charge (Qrr) is negligible at 14% for all of the minor components. This feature is suitable for applications that do not have hard switching diode bridges such as motor drives, inverters, inverter PVs, and totem pole PFCs.

6 is a diagram comparing a demonstration board using a general LLC converter and a gallium nitride high electron mobility transistor. As shown in FIG. 6, when the switching frequency is increased to 200 kHz in order to improve the characteristics, the size of the LLC portion is reduced by 40%. In addition, weight and cost can be reduced by minimizing the number of arrays due to the increase in efficiency.

FIG. 7 shows waveforms of a general power factor controller, and FIG. 8 shows waveforms at soft-start and brown-out. 9 is a graph showing Vdc waveform Volt, current waveform, and rising polling time. Thus, it can be seen that the efficiency is increased by increasing the general switching frequency up to 200 kHz.

FIG. 10 is a result of checking the heat generation characteristics of the main parts, and shows a result of photographing a state of the normal operation state of each major part under a 250 W full load state by using the thermal imaging camera by applying the system proposed in the present invention. As a result of measuring the temperature at 250W (12V / 20A), it showed 60 ~ 65 ℃ without heat sink. Compared with general transformer, the superiority of the present invention can be proved. It can be seen that the heat sink size can be drastically reduced.

In the present invention, it is possible to control the LLC gate portion and the SR driver by adding a concealing circuit. 11 shows the control circuit applied to the gate of the LLC resonant converter. As shown in Fig. 10, the control circuit 1000 may be composed of diodes SD1 and SD2 and loads RP13 and PR12. The control circuit 1000 is an LLC controller circuit that is applied to the gate of at least one of the LLC resonant circuit portions 150 of FIG. 1, for example, transistors Q1, Q2 and Q3 to determine the frequency characteristics of the voltage delivered by the input portion 140 So that the frequency can be freely controlled.

12 illustrates a concealed circuit applied to the synchronous rectification driver. The control circuit 1100 of Figure 11 is included in the synchronous rectification section 110 and is connected to the gates and sources of the switching elements of the output side synchronous rectification section 110 and the secondary winding of the transformer Tr of Figure 1, It is possible to control the operation of the switching element of the switching element.

For example, the frequencies of the control circuits 1000 and 1100 can be varied freely within the range of 300 to 700 W in the A type-300W, the B type-500W, and the C type-700W. According to the present invention, by applying the converter of the present invention to a DC-DC converter as a concealment circuit (HID), the efficiency and the capacity can be diversified.

13 shows a circuit diagram and operation waveform of a low-voltage DC converter applied to an electric vehicle according to an embodiment of the present invention. 13A, the low voltage DC converter 130 may include a gate driver section 131, a resonant driver section 133, and a rectifier section 135.

The gate driver section 131 may include a gate driver IC to which a gallium nitride high electron mobility transistor is applied, and may include a Half Bridge LLC resonant converter or a Full Bridge LLC resonant converter. The gate driver IC may be designed to operate at a switching frequency in the range of 400 KHz to 1 MHz.

The resonance type driver section 133 may include an LLC resonance type Driver IC. FIG. 13B shows an operation waveform according to the operation mode of the LLC resonant converter, showing the zero-current conversion (ZCS) before turn-off and the zero-voltage conversion (ZVS) before turning on. Referring to FIG. 13B, at zero current conversion, the current flows through the body diode of another MOSFET before the MOSFET is turned on. When the MOSFET switch is on, the reverse recovery stress of the MOSFET's body diode becomes very severe. This high reverse recovery current spike can not flow through the resonant circuit, so it flows through another MOSFET switch, which produces a high body diode dv / dt whose current and voltage spikes are depleted during the reverse recovery of the body diode ≪ / RTI > Therefore, the converter should not operate in the capacitive range, and if fs> fr1, the input impedance of the resonant tank is inductive. During zero voltage conversion, the MOSFET turns on at zero voltage (ZVS). The turn-on conversion loss is minimized because there is no Miller effect and the MOSFET input capacitance is not increased by the Miller effect. The reverse recovery current of the body diode is also part of the sinusoidal wave and becomes part of the switch current when the switch current is positive. Therefore, ZVS can be preferred over ZCS in general because it can eliminate major conversion losses and stresses due to reverse recovery current and discharge of junction capacitance.

Meanwhile, the safety circuit may include at least one of Over Voltage Protection (OVP), Under Voltage Protection (UVV), Over Current Protection (OVP), Over Temperature Protection (OTP)

The rectifying unit 135 may include a secondary side synchronous rectifier and a driver IC. On the secondary side synchronous rectifier, devices such as Infineon / On Semi / Texas ins) can be applied.

The driver IC may be a dedicated driver IC operating at a switching frequency of 400 KHz or higher. Also, MOSFETs can be applied instead of diodes for high-speed switching.

The rectification section 135 allows the low voltage DC converter 130 of the present invention to maintain high efficiency at a low voltage. In addition, it is efficient in comparison with a diode having a loss voltage of 0.2V and a diode of 0.6V in switching. In addition, even if the load current is abruptly reduced, the active control can be performed, and the response characteristic according to the load variation can be very excellent. Even when no load is applied, the output rudder can be maintained with the cycle ratio, and the low noise can be maintained at the time of light load.

Figure 14 shows a circuit diagram and operational waveform of a battery charger according to an embodiment of the present invention.

Referring to FIG. 14A, the battery charger 140 may include an input unit 141 and a boost converter unit 143.

In the input unit 141, the input EMI filter and the rectifier can perform the protection function for the primary side circuit. Also, the input unit 141 may block the AC power supply (AC Input) when an error occurs. Film capacitors can provide input decoupling charging storage to reduce input ripple current at switching frequencies and harmonics. The NTC thermistor can limit the inrush current when the line voltage is first applied.

The boost converter unit 143 can maintain the input current to the power source which is the AC power supply. The inrush current path can be provided to the capacitor C12 to prevent resonant interaction between the switching inductor and the output capacitor.

The battery charger 140 may further include a storage unit 145. The storage units 145 and C12 may function as an output filter and an energy storage for power factor correction (PFC) output. On the other hand, the output feedback can constitute a voltage divider that provides a scaled voltage proportional to the output voltage as feedback to the controller IC U1 by setting the boost output to 385VDC, as shown in Fig. In the boost converter section 143, the capacitor C7 attenuates the high-frequency noise.

14B shows a waveform when the power factor corrector is operated at a magnitude of 100 V (left) or 230 V (right), and FIG. 14C shows an AC input voltage (left) and an AC input voltage (right).

15 shows a circuit diagram and operational waveform of a battery charger applied to an electric wheelchair or electric scooter according to an embodiment of the present invention.

Referring to FIG. 15A, the battery charger 150 includes a DC direct current converter unit 151, a voltage current controller 153, and a rectifier unit 155.

The DC-DC converter 151 (DC-DC converter) can operate such that the output terminal is a constant voltage or a constant current. As a control circuit required for the forward converter and the flyback standby converter, a dedicated driver IC for securing a switching frequency of 200 KHz as shown in FIG. 15A may be included. FIG. 15B shows waveforms when the power factor corrector is operated at a magnitude of 100 V (left) or 230 V (right).

The voltage current controller 153 can control the output voltage and the output voltage using a sensing resistor (not shown) at the output terminal. On the other hand, standby power can be used outside. 15C shows the operation waveforms in the CV mode (left) and the CC mode (right) according to the Main Output Start-up.

 The rectifying section 155 rectifies the voltage and current and removes the noise. The bias voltage winding is applied to the transistor T2 in the former stage of the rectifying section 155 and can be output and applied at 5V. The applied voltage is rectified and filtered by capacitors C32, C33, C36. High frequency ripple and noise are then eliminated by the inductor L5, and the RC serial stages R51 and C34 constitute a soft start network to eliminate the overshoot of the output voltage at startup.

16 shows a circuit diagram and operational waveform of a battery charger applied to an electric motorcycle according to an embodiment of the present invention.

Referring to FIG. 16A, the battery charger 160 may include an input unit 161 and a charging unit 163 based on the voltage winding conversion unit T 1.

The input unit 161 can use a high line input flyback power source of 59V / 120W. Secondary control circuit can be applied for use in battery charger Apple. In addition, the input unit 161 may further include a dedicated driver IC for securing a switching frequency of 200 KHz. 16B shows a waveform that operates in the output start-up CC mode or the CV mode. A space and efficiency can be increased by using a one-chip composed of an FET and a driver in the input unit 161. The input section 161 is designed to operate without a fan and can switch to a low output current limit. While the protection circuit can be operated in at least one of OVP, UVP, OCP and OTP modes.

The charging unit 163 may be configured as a fly-back battery charger supply, and may be configured as an on-board type of about 120W.

Also, the charging unit 163 may include an operational amplifier LM358D to charge the battery while sensing the state of the battery. Here, the output current is sensed to provide a reference for the output current or the output voltage, and the output voltage is compared with the reference voltage by charging the output voltage when the output voltage falls below 0.5 A. The charging unit 163 can control the output voltage and the output current while operating in CC MODE or CV MODE, and the nominal trip temperature can be set to 100 DEG C or the nominal reset temperature can be set to 70 DEG C. [ 16C shows the operating power factor waveform.

In the embodiments disclosed herein, the arrangement of the components shown may vary depending on the environment or requirements in which the invention is implemented. For example, some components may be omitted or some components may be integrated into one. In addition, the arrangement order and connection of some components may be changed.

Although the present invention and its various functional elements have been described in terms of specific embodiments, it is to be understood that the invention may be implemented in hardware, software, firmware, middleware, or a combination thereof and may be implemented as a system, subsystem, It should be understood that the invention may be utilized in various other embodiments. When implemented in software, the elements of the present invention may be instructions / code segments for performing necessary tasks. The program or code segments may be stored in a machine-readable medium, such as a processor-readable medium, or a computer program product. A machine-readable medium or a processor-readable medium may include any medium that can be read by a machine (e.g., processor, computer, etc.) and capable of storing or transmitting information in an executable form.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Accordingly, the technical scope of the present invention should be determined only by the appended claims.

130: Low-voltage DC converter
140, 150, 160: Battery charger

Claims (10)

In a low-voltage DC converter,
A gate driver section including a gate driver IC and an LLC resonant converter to which a gallium nitride high electron mobility transistor is applied;
A resonant driver section including an LLC resonant driver IC; And
A secondary side synchronous rectifier and a driver IC. The method according to claim 1,
The gate driver IC is operated at a switching frequency ranging from 400 KHz to 1 MHz. The method according to claim 1,
Wherein the driver IC of the rectifying part is a dedicated driver IC operating at a switching frequency of 400 KHz or more. In a battery charger,
An input unit for performing a protection function for the primary side circuit; And
And a boost converter portion providing an inrush current path to the capacitor to maintain an input current to the AC power supply and to prevent resonant interaction between the switching inductor and the output capacitor. 5. The method of claim 4,
A battery charger further comprising an output filter and a storage for energy storage for power factor correction (PFC) In a battery charger,
A direct current (DC) converter unit operable to output a constant voltage or a constant current;
A voltage current controller for controlling at least one of an output voltage and an output voltage using a sensing resistor at an output terminal; And
And a rectifying section for rectifying the voltage and the current and removing the noise. The method according to claim 6,
Wherein the DC direct current converter section operates as a control circuit required for the forward converter and the flyback standby converter. The method according to claim 6,
And at least one of the transistor, the capacitor, and the inductor. In a battery charger,
An input including a high line input flyback power supply of 59V / 120W and a secondary control circuit; And
Fly-back battery charger A battery charger consisting of a charger supply and an on-board charging unit. 10. The method of claim 9,
The charging unit 163 includes an operational amplifier LM358D to charge the battery while sensing the state of the battery, and controls the output based on the output current or the reference of the output voltage.

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