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© 2011 Fairchild Semiconductor Corporation www.fairchildsemi.com Rev. 1.0.0 • 9/9/11

AN-9742 Device Selection Guide for Half-Bridge Welding Machine

(IGBT & Diode)

Summary

Various topologies; including two SW-forward, half-bridge

and full-bridge, have been used for low-voltage / high-

current DC-ARC welding machines for system minimization

and efficiency improvement. Of these topologies, half-

bridge is the most commonly used for small form factor, less

than 230A capacity welding machines. Compared to full-

bridge topology with the same power rating, half-bridge

requires more transformer wiring and higher current

capacity of inverter; but requires fewer power devices.

Taking a Fairchild evaluation board as the example, this

article presents a device selection guide for a half-bridge

welding machine application.

Description of Welding Machine

Generally, based on the type of welding machine, the output

voltage can be calculated as shown in Table 1.

Table 1. Welding Machine Output Voltage

Welding

Machine Output Voltage Example

CO2 0.04•IAC+15 0.04•200A+15=23V

TIG 0.04•IAC+10 0.04•200A+10=18V

DC ARC 0.04•IAC+20 0.04•200A+20=28V

Duty Cycle of a Welding Machine

In the welding industry; duty cycle refers to the minutes out

of a 10-minute period a welder can be operated at maximum

rated output without overheating or burning up the power

source. For instance, a 140A welder with a 60% duty cycle

must be “rested” for at least 4 minutes after 6 minutes of

continuous welding at maximum rated output current 140A.

Allowable Duty Cycle

If actual current in use is smaller than a rated output current,

the welder internal heating decreases. The welder then can

be used at a higher rate than the specified duty cycle. Its

allowable duty cycle can be calculated as:

machine weldingof cycleduty currentoutput using

currentoutput rated2

×

= (1)

For example, since only 80A to 130A current would be

required to weld a 3.2 welding rod, a 140A welder with a

60% duty cycle can operate for a longer time for this

application. Assuming 100A is used to weld a 3.2 welding

rod, actual duty cycle is more than 78.4%.

Besides the actual output current, the temperature also

affects the allowable duty cycle of a welding machine.

Do NOT overheat welder machines.

Table 2. Feasible Welding Materials by Welding Machine

Welding Machine Gas Welding Type Steel

CO2 CO2 Mild, High Tensile

MIG He + Ar Aluminum, SUS, Aluminum Alloy

MAG Sheet Metal, Low Alloy, High Tensile

DC-TIG Stainless, Mild, Copper Alloy, Nickel Alloy, Titanium Alloy, Low Alloy

AC-TIG Aluminum Alloy, Magnesium Alloy, Bass

Mixed TIG Light Alloy, Clad Plate

DC-ARC Steel, Nonferrous Metals

AC-ARC Aluminum

AN-9742 APPLICATION NOTE

© 2011 Fairchild Semiconductor Corporation www.fairchildsemi.com Rev. 1.0.0 • 9/9/11 2

Fairchild DC-ARC Welding Machine Evaluation Board

Evaluation Board Features

� Input Stage: 50A Bridge Diode (600V, 50A, Square-

Bridge Type)

� Input Filter Stage: Designed Under Consideration of

Conductive Noise and Radiation Noise

� Controller: PIC16F716 (8-Bit ADC and 10-Bit PWM)

� Inverter Stage: FGH40N60SMD (within Co-Pak Diode)

Single or Parallel

� Output Rectifier: FFA60UP30DN * Six Units (Three

Ultra-Fast Diode in Parallel)

� Gate Driver: Opto-Coupler for the Isolation between

Switching Devices and Controller Dual Power Supply

+15V, -5V for IGBT Gate Voltage

� AUX Power Supply: Lower Standby Consumption Green

Integrated PWM IC

� Input Voltage and Frequency: 220VAC 60Hz

� Output Voltage (VOUT) and Output Current (IWEL):

26VDC, 140A

� Efficiency: > 80%

� Idle Power: < 4W

� Switching Frequency: 20KHz

Figure 2 shows the main block diagram of the welding

machine evaluation board. The output current and output

voltage of the DC-ARC welding machine evaluation board

are 26V and 140A, which constitutes a 3kW-class welding

machine. Various Fairchild Semiconductor components are

used to meet the design requirements. The switching

frequency of the machine is 20KHz. Due to their size; the

transformer and inductor are installed beside the board. An

air fan is attached for cooling.

Figure 1. Evaluation Board

Figure 2. Main Block Diagram



Half-Bridge Inverter Design

The turn ratio of the primary and secondary of the

transformer in a half-bridge topology can be obtained from

the equation:

4

)(1

SWe

MAXMININ

fAB

DVN

∗××

×=

(2)

)(

)(

11

MININMAX

IFO

VD

NVVVN

×

×++= (3)

where VI = VS, IWEL = output current, Id1 & Id2 = diode

current (output high side & output low side).

Output voltage under no load condition is given by:

( )MAX

IFOnolaod

D

VVVV

=+= (4)

where:

VO=output voltage;

VF=diode drop voltage; and

VI=inductor voltage drop.

Transformer’s primary and secondary current can be

obtained by:

( )MAXWELrms DIN

NI ×××= 2

1

21 (5)

( )MAXWELrms DII ×+××= 212

12 (6)

Current running through the IGBT and secondary-side

rectifier diode can be calculated by:

WELIN

IGBT ×=1

2D

NI :Current (7)

Output rectifier diode voltage and current:

22

21)( ,

1

2ddWELMAXINr IIIV

N

NV +=×= (8)

IGBT Selection for Welding Machine

Among various power switching components, Insulated Gate

Bipolar Transistor (IGBT) is the most suitable device for

welding machines thanking for its high current handling

capability and high switching speed. IGBT is a voltage-

controlled power transistor, similar to the power MOSFET

in operation and construction. This device offers superior

performance to the bipolar-transistors. It is the most cost-

effective solution for high power and wide frequency-range

applications. Table 3 shows the characteristics comparison

of IGBT with BJT and MOSFET.

Table 3. Device Characteristics Comparison

Features BJT MOSFETS IGBT

Drive Method Current Voltage Voltage

Drive Circuit Complex Simple Simple

Input Impedance Low High High

Drive Power High Low Low

Switching Speed Slow(µs) Fast(ns) Middle

Operating Frequency

Low Fast

(less than 1MHz) Middle

S.O.A Narrow Wide Wide

Saturation Voltage

Low High Low

Power losses of an IGBT include conduction loss and

switching loss. The conduction loss is determined by

IGBT’s Vce(sat) value and the duty rate. The switching loss is

determined by turn-on and turn-off action during IGBT’s

switching transient. For IGBTs, there are technical trade-off

characteristics between the Vce(sat) and the switching loss. If

Vce(sat) is high, switching loss becomes low and vice versa.

Therefore, the designer should select an IGBT based on the

system configuration and its switching frequency. The total

loss of an IGBT can be expressed as:

Total Loss

=1 Pulse Switching Loss (EON + EOFF)

X Switching Frequency

+ Conduction Loss

(VCS(SAT) X IC X Duty) (9)



Figure 3 curves show the characteristics comparison

between PT IGBT and field-stop IGBT. PT IGBT has NTC

temperature characteristic: as temperature rises, Vce(sat)

decreases. Field-stop IGBT has PTC temperature

characteristic: as temperature rises, Vce(sat) increases.

Therefore, PT IGBT with NTC characteristic is more

suitable for the application where IGBT is operated solely.

However, if parallel operation of IGBTs is required for

current sharing, field-stop IGBT with PTC characteristic

would be more appropriate.

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

0

10

20

30

40

50

60

70

80

FGH40N60SMD

FGH40N60UFD

FGH40N60SFD

HGTG20N60A4D

Collector Current, Ic[A]

Collector-Emitter Voltage, Vce(sat)[V]

Tc=25deg.C

Vge=15V

Figure 3. HGTG20N60A4D(PT) vs. FGH40N60UFD/SFD

(Field-Stop Gen1)

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

0

10

20

30

40

50

60

70

80


FGH40N60SMD

FGH40N60UFD

FGH40N60SFD

HGTG20N60A4D

Tc=125deg.C

Vge=15V


Figure 4. FGH40N60SMD (Field-Stop Gen2)

Reduction of conduction loss and total device cost with

better thermal performance would be the advantage of the

parallel operation of IGBTs. However, for such kind

application, the following must be considered:

� Using high-temperature PTC characteristic IGBT

� Using gate resistor with ≤1% tolerance for each IGBT

� Proper gate PCB layout for symmetrical current paths

� Identical heat sink size and airflow for each IGBT

� Same threshold voltage and saturation voltage

characteristics

The following figures show that the switching loss becomes

the dominant factor over conduction loss in 25kHz and

above switching frequency area.

10 20 30 40

0.0

0.5

1.0

1.5

2.0

Test Condition :

Vcc=400V, Rg=10 ohm, Vge=15V

Tc=25deg.C

Tc=125deg.C

FGH40N60SMD

FGH40N60UFD

FGH40N60SFD

HGTG20N60A4D

Total Switching Loss[Eon+Eoff], Ets[m

J]


Figure 5. Total Switching Loss Ets

vs. Collector Current IC

20.0k 40.0k 60.0k 80.0k 100.0k

0

50

100

150

200

250

Test Condition :

Vcc=400V, Rg=10 ohm,

Vge=15V, Ic=40A, Tc=125deg.C

FGH40N60SMD

FGH40N60UFD

FGH40N60SFD

HGTG20N60A4D

Total power loss of IGBT, Pd [W]

Switching Frequency, Fsw[KHz]

Conduction loss

Switchin

g loss[ Eon+ Eo

ff]

Total po

wer lo

ss

Figure 6. Total Power Loss of IGBT Pd

vs. Switching Frequency

The gate resistor is also very critical to the switching loss.

High gate resistance results in high switching loss. On the

other hand, high gate resistance improves EMI performance

as the di/dt is lower during the switching transient. A

properly selected gate resistor should minimize the

switching loss without sacrificing system EMI performance.



Below are the IGBT turn-off characteristics measurements

with JIG testing. Under the same conditions, FS Planar

Gen2 IGBT FGH40N60SMD shows faster switching

characteristic, lower Vce(sat), and tremendously lower turn-off

loss compared to previous technology devices - PT and FS

Planar Gen1 IGBT.

5 10 15 20 25 30

0.2

0.4

0.6

0.8

1.0

Test Condition :

Vcc=400V, Ic=40A, Vge=15V

FGH40N60SMD

FGH40N60UFD

FGH40N60SFD

HGTG20N60A4D

Tc=25deg.C

Tc=125deg.C

Switching Loss, Eoff[m

J]

Gate Resistance, Rg[ohm]

Figure 7. Turn-Off Loss EO vs. Gate Resistance Rg

1.6 1.8 2.0 2.2 2.4

8

12

16

Tc=25deg.C

FGH40N60SMDFGH40N60SFD

HGTG20N60A4D

FGH40N60UFD


Switching loss, Eoff / A[uJ]

Figure 8. Turn-Off Loss EOFF vs. Collector-Emitter

Vce(sat)

Figure 9 and Figure 10 show the IGBT operation waveforms

of the evaluation board with R-load and welding load. These

waveforms reveal that welding load consumes three times

the current that R-load consumes. Therefore, it is important

to select IGBT with suitable Icm parameter to avoid

saturation at peak-current condition.

Figure 9. R-Load Test at IOUT=14A

Figure 10. Welding-Load Test at 3.2 Pie Welding Rod



Figure 11 through Figure 16 show turn-off switching loss

EOFF measurement with welding load and R-load. Due to the

leakage inductance and capacitor element, there is huge

difference in EOFF measurement compared with the JIG test

result. The EOFF of FGH40N60SMD shows the lowest loss

from the test.

Figure 11. EOFF Comparison Under

R-Load (FGH40N60SMD)


R-Load (FGH40N60UFD)


R-Load (FGH40N60SFD)


Welding Load (FGH40N60SMD)


Welding Load (FGH40N60UFD)


Welding Load (FGH40N60SFD)



Rectifier Diode for Welding Machine

Fairchild Semiconductor provides five kinds of diodes that

cater to different applications. Diodes with lower Vf, Irr, and

Trr characteristics are ideal for welding applications;

however, the common P_N theory dictates that the lower the

Vf, the longer the Trr and vice versa. A designer chooses a

diode with a trade-off point where Vf and Trr benefit the

system efficiency the most. The following figures show

performance comparisons for 600V/8A diodes from each

Fairchild Semiconductor diode technology.

0 20 40 60 80

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

Stealth2 Ulrafast

Hyperfast

Hyperfast2

Stealth

Stealth2

Stealth

Hyperfast2Hyperfast

Ultrafast

Tc=25deg.C

VF [V]

Qrr [nC]

FCS Rectifier Diode Vf vs Qrr, 600V 8A

Figure 17. VF vs. Qrr Trade-Off

-80.0n -40.0n 0.0 40.0n 80.0n 120.0n 160.0n-12

-10

-8

-6

-4

-2

0

2

4

6

8

10

Tc=125deg.C

IF [A]

Time [sec]

Ultrafast

Hyperfast

Hyperfast2

Stealth

Stealth2

FSC Rectifier performance @ 600V, 8A

Figure 18. Reverse Recovery Performance

Figure 19. Test Circuit and Waveforms

rrrrrr tIQ ××=2

1 (10)

Generally, the rectifier diode of welding machine has higher

conduction loss than reverse recovery loss. Therefore, the

diode VF value is more critical for a welding application.

For this reason, ultra-fast diode FFA60UP30DN (30A dual

diode) is used for this evaluation board. Three diodes are

used in parallel for each tap of transformer to lower the VF.

The figures below show the performance of diodes used in

single and parallel configuration. Although the reverse

recovery loss increases, Vf is reduced with parallelized

diodes and better thermal performance can be expected.

Designer caution is required for parallel diode application to

ensure that the air flow does not cause unbalanced current

conditions, as the Vf of diode tends to decrease when the

temperature rises.

0.0 0.6 1.2 1.8

0

20

40

60

80

100

Tc=25deg.C

Tc=125deg.C

VF, Forward Voltage [V]

FFA60UP30DN-Dual

FFA60UP30DN-single

IF, Forward Current [A]

Diode I-V charateristic

Figure 20. Diode I-V Characteristic

100 200 300 400 500

0

60

120

180

240

300

360FFA60UP30DN Qrr charateristic

Tc=25deg.C

Tc=125deg.C

Stored Recovery charge Q

rr [nC]

di/dt [ A/us]

VR = 150V

IF = 30A

Single

Dual

Figure 21. Stored Recovery Charge Qrr vs.

Diode Current Slop di/dt



Figure 22 shows the diode switching loss when the board is

operating at 20KHz. The conduction loss is about 336µJ,

while the reverse recovery loss is only about 4µJ.

Figure 22. Diode Conduction Loss During Welding

Figure 23. Diode Reverse Recovery Loss

During Welding

Avalanche occurs in a diode with sudden current increase

when the voltage across a diode exceeds the specified Vr

value. Here, the area (Vr(AVL)*Isa) that diode does not fail is

called avalanche energy and the equation is:

])(

[2

1

)(

)(2

DDAVLr

AVLr

saAVL

VV

VILE

−

×××=

)()( )(1 AVLrces VDUTBVIGBTQ >=∴

(11)

Avalanche energy is occurred by the second output inductor,

as shown in the equation. The immunity capability is

proportional to the inductance. The inductance of a welding

machine is generally designed as small value as several µH,

and diode immunity capability value becomes an important

factor for choosing a device.

Avalanche can occur in the secondary-side rectifier of a

welding machine; especially when the welding work is

completed and the reverse pass occurs by inductor.

Immunity capability is measured using a circuit as shown in

Figure 24 with the graph in Figure 25 showing avalanche

energy test result waveform.

Figure 24. UIS Test Circuit

Figure 25. FFA60UP30DN Immunity Capability

Blocking Capacitor

For half-bridge topology; if the two series DC bank

capacitors or the turn-on time of IGBTs are not matched,

DC flux occurs in the transformer. The accumulated DC flux

eventually drives transformer into saturation. The IGBTs

can be destroyed by sharply increased current due to the

saturated transformer. To block the DC flux in the

transformer core, a small DC blocking capacitor is placed in

series with the transformer primary. The value of the DC

blocking capacitor is given by:

swP

D

blocking

FV

IDC

×∆×

=max

(12)

where PV∆ is the permissible droop in primary voltage due

to the DC blocking capacitor.

Below is the waveform of the transformer primary current.

The current abruptly rise due to the saturated transformer

caused by DC bias.

Figure 26. IGBT Saturation Current



Figure 27. Zoom of IGBT Saturation Current

Power Supply Structure and Design

MOSFET integrated IC FSMG0465R is used for power

supply. Its simple peripheral circuit and 66KHz switching

frequency reduce the PCB and transformer size. In addition,

the efficiency of power has been maximized by the

minimization of idling power that can be achieved from low

power consumption in Standby Mode (<1W at 230VAC input

at 0.5W load). There are transformer type and SMPS type

for the substitute power supply. SMPS type, compared to

linear transformer type, has stable output power over the

influence of input serge, sag, and noise; and minimal design

of size and weight is possible. In addition, transformer type

has a fixed input voltage, whereas SMPS has a wide input

voltage range of 80VAC~264VAC, which can be used for free

voltage welding machine without additional operation.

However, it is necessary to consider counter measures for

noise as the switching noise may affect main inverter. For

further information about Fairchild Power Switches

(FPS™), refer to the application note AN-4150 found at:

http://www.fairchildsemi.com/an/AN/AN-4150.pdf.

Controller Design

The evaluation board uses PIC16f716 for the control

circuits. PIC16f716 controller consists of four ports of 8-bit

AD converter and one port PWM timer with 9-bit, 40KHz

resolution. To generate two PWM pulses from one PWM

signal, a D flip-flop and an AND gate are used to divide the

40KHz PWM into 20KHz PWM pulse (see Figure 28).

Figure 28. PWM Convert 40KHz to 20KHz

Gate Driver Design

A transformer, opto-coupler, or HVIC can be used for a gate

driver. Necessary supply voltages for different gate drivers

are listed as:

� HVIC Driver: +15V, 0V (High and Low Gate),

+ 24V, 0V (Output Detect), +5V, 0V (Controller)

Otpo-Coupler Driver : +15V, 0V, -5V (High-Side Gate),

+15V, 0V, -5V (Low-Side Gate), +24V, 0V (Output Detect),

+5V, 0V (Controller)

Pulse Transformer: +24V, 0V (Output Detect),

+5V, 0V (Controller)

The opto-coupler and transformer provide isolation between

the control circuit and IGBTs. However, a transformer may

cause half bridge cross-conduction due to the offset voltage

of gate-pulse dead-time stage. Through an by integrated

high-voltage MOSFET, the HVIC provides isolations

between the control circuit and the high-side IGBT. This

does not work with negative supply voltage. A negative

supply voltage is necessary for HVIC during a fast

commutation in a half-bridge topology to prevent dv/dt

shoot-through. The shoot-through is linked to a fast voltage

variation across one of the two IGBTs. A current flowing

through collector-emitter capacitor can bring the gate

voltage of an IGBT, when turned off, to rise due to Miller

effect and obtain a cross conduction into the leg.

C11

10uF/10V

C19104

C20104

D1

1N4937

D2

1N4937

D3

1N4937

-15V

C21104

D4

1N4937

C822P

+15V

+15V

C22104

-15V

J2

Output 12

RD2

ERR

Y1

WLD

C3104

J1

Current Limit

123

C23104

R8

10k R91k

VR35k

VR15k

C6

105

G3

PWR

R6

1K

R13 330

R12 330

Temp

+5V

+5V

J3

CT 12

C4104

R11 330

D5

1N4937

U2A

7474

CLK3

CL

R1

D2

PR

E4

Q5

Q6

U1 PIC16C711

GN

D5

VD

D1

4

OSC2/CLKOUT15

MCLR/VPP4

OSC1/CLKIN16

RA0/AN017

RA1/AN118

RA2/AN21

RA3/AN3/VREF2

RA4/TOCKI3

RB0/INT6

RB17

RB28

RB39

RB410

RB511

RB612

RB713

J1

TH 12

R110 ohm/3W

X1

20Mhz

C1

22uF/10V

U5

PS25012

35

8

4

6

U6

PS25012

35

8

4

6

VR25k

R20330

ZD!

1N4099

12

R2

27k

U3A

7409

1

23

R3

1k

U4B

7409

4

56

C2104

R19330

R101K

C7104

+5V

C922P

+5V

+5V

+5V

R16 330

R15 330

R14 330

+5V+5V +5V

C12104

+5VBD1

1

2

Gate2_1

C15104

C16104

gate2_2

+5V

RD1SD

G2

Cont-

G1

Cont+

+5V

gate1_2

Gate1_1

R18 1K

R17 1K

C13470P

C14470P

R71K

LVD

R4

36k

C5104

+5V

+5V

R5

560

Q2

2n3904d/ON

Q1

2n3904d/ON

Temp

C10104

PC1PC817

12

43

Figure 29. Controller Schematic



dtdVGICG

CG /××××====Q

CGgge IRV ×=

CGCG CdtdvI ×= /

Figure 30. Effect on dv/dt to VGE

Figure 31. Effect on dV/dt to Gate Wave

Based on the above considerations, an opto-coupler is used

for this welding machine evaluation board. Figure 32 and

Figure 33 present the gate waveforms captured with

different types of gate drivers. It is clear the opto-coupler is

the best choice for this welding application.

Figure 32. HVIC Gate Waveform

Figure 33. Transformer Gate Waveform

Figure 34. Opto-Driver Gate Waveform

DC Reactor Design

DC reactor helps stabilize arc current during welding

operation. As DC reactance grows, specter occurs smaller.

On the contrary, if the mobility of arc is lowered and the LDC

value gets too large, it is harder to create an arc. Therefore,

an appropriate reactor choice is necessary. If considering

VOPEN as output no-load voltage, VWEL and IWEL as rated

output voltage or current; the maximum LDC value can be

obtained from the equation:

:

)1( RV

IIn

tRL

open

WEL

R

DC

×−

×−≤

(13)

where R is the equivalent resistance of welding load and Tr

is the rising time of the output current from 0 to the rated

current. Once the maximum LDC value is obtained; the

optimum LDC value can be finalized through testing.

Figure 35. Soft-Start During Welding Operating

Figure 36. Welding Operating



Conclusion

Better performance is expected for a DC-ARC welding

machine when the inverter devices are selected properly

based on the inverter topology and its switching frequency.

This article presents a power device selection guide for a

half-bridge welding machine application.

When to chose an IGBT, its Vce(sat), Eoff turn-off loss, gate

driver resistor, and Icm characteristics are the critical factors

that require a designer’s careful attention.

For the secondary -side rectifier diodes, it is important to

determine which is the dominant factor, Vf or reverse

recovery loss, based on system switching frequency. The

evaluation board uses three ultra-fast diodes

(FFA60UP30DN) in parallel for each tap of the transformer

to lower the Vf and therefore the conduction loss.

References

[1] Aspandiar, Raiyo, “Voids in Solder Joints,” SMTA Northwest Chapter Meeting, September 21, 2005,

Intel® Corporation.

[2] Bryant, Keith, “Investigating Voids,” Circuits Assembly, June 2004.

[3] Comley, David, et al, “The QFN: Smaller, Faster, and Less Expensive,” Chip Scale Review.com, August /

September 2002.

[4] Englemaier, Werner, “Voids in solder joints-reliability,” Global SMT & Package, December 2005.

[5] IPC Solder Products Value Council, “Round Robin Testing and Analysis of Lead Free Solder Pastes with Alloys of

Tin, Silver, and Copper,” 2005.

[6] IPC-A-610-D, “Acceptance of Electronic Assemblies,” February 2005.

[7] IPC J-STD-001D, “Requirements for Soldered Electrical and Electronic Assemblies.”

[8] IPC-SM-7525A, “Stencil Design Guidelines,” May 2000.

[9] JEDEC, JESD22-B102D, “Solderability,” VA, Sept. 2004.

[10] Syed, Ahmer, et al, “Board-Level Assembly and Reliability Considerations for QFN Type Packages,”

Amkor Technology, Inc., Chandler, AZ.

Related Resources

FGH40N60SMD — 600V, 40A Field Stop IGBT

FFA60UP30DN — 300V Ultrafast Recovery Power Rectifier

FSGM0465R — SMPS Power Switch, 4A, 650V (Green)

Appendix — Circuit Diagrams

C5110uF 630V

2

T1

TRANSFORMER CT

1 5

6

4 8

D3 FGA60UP30DN

D7 FGA60UP30DN

D16 FGA60UP30DN

D17 FGA60UP30DN

D18 FGA60UP30DN

D19 FGA60UP30DN

R6

10

- Output

C23

102

R39

10

C24

102

+ Output

ZD81N4744

ZD91N4733

R54.7k

Gate1

Gate2

C5210nF 630V

ZD71N4733

R44.7k

ZD31N4744

ZD41N4733

Z4

FGA40N60SMD

R9 10/3W

C5310nF 630V

Z2

FGA40N60SMD

R3 10/3W

GND1

ZD61N4744

C541uF M275V

C55472M

C62472M RV1

20D431K

RV220D431K

RV320D431K

P10

1

P11

1

P3

1

L6

L5

LF1RFILTER

L4 52uHC2

400V 560uF

Z3FGA40N60SMD

Z1FGH40N60SMD

R8 10/3W

R74.7k

R1 10/3WZD11N4744

ZD21N4733

R24.7k

-+

BD1

GBP5006

2

1

3

4C1

400V 560uF

- BUS

C61

630V

+ BUS

GND2FAN

1

Gate1

Gate2

C5010uF 630V

CT1

JF3250G

1 3

Figure 37. Main Circuit



L2 10uH

XY

4.7nF/1KV

R204

1K

F201 250V 2A

U201 FGM0465R

FB4

Drain1

GN

D2

Vstr6

Vcc3

R2011M/1W

C214

47nF

R217

1.2k

C216

1000uF 10V

D202

1N4007

D203

MBRF10H100

-+

BD201

2KBP06M3N25

2

1

3

4

R219

8K

R208

1k

C213

102

C224470uF 35V

R2051K

C207

47uF 50V

PC1

12

R215

10

U202TL431

23

1

D201

UF4004

LF201

30mH

D204

MBRF10H100

L1 10uH

R218

18K

C202275Vac 100nF

C215

470uF 10V

C2083.3nF 630V

R202

270K

PC2 817

12

43

C204

47nFD38

1N4744

1

2

D206

MBRF10H100

T101EER3940S

13

7

8

9

10

11

12

14

15

16

3

1

TNR10D471k

C209 102

R216

620

C210

102

L5

4.9uH

C203400V 100uF

R212

10

ZD2011N4745A

1

2

C223

470uF 35V

+15v

gnd

5v

AC220V H

AC220V N

-15V

GND2

C201275Vac 100nF

R20743K/1W

R20675K

C20533nF 100V

C206

100nF

R210

1W 5

R220

8K

R203150K

Q201

2N2222

R211 10

NTC

NTC1

5D-9

R209

100 ohm/0.5W

GND1

L4 10uH

D205

MBRF10H100C220

470uF 35V

D207

MBRF10H100

L3 10uH

C211102

C212102R214 10

C219470uF 35V

15+v

-15V

R21310

C217

470uF 35VC218

470uF 35V

C211470uF 35V

C222470uF 35V

Figure 38. Auxiliary Power Supply

Figure 39. Controller

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