91811 schematic unified
TRANSCRIPT
1 of 4KENDE TIG WELDERAKA: HARBOR FREIGHT #91811
REV 0.6PAGEUNIFIED
Reverse IP by [email protected]. Modifications,Documentation, Copyright (c) 2008-2009 [email protected]
J3
IGB
T D
RIV
E
B2
E2
B1
E1
SWAPPED RELATIVE TO PCBLEGEND TO DRIVE IGBTSOUT OF PHASE
IGB
TF
EE
D
J5
J1
CURRENTTRANSFORMER
-START
+START
THERMAL SWITCHKDS-R303 65˚C
2MB
I 100
N-0
60
50:1
10uF 600V
10uF 600V
3.5T11T
3.5T
B1
CORE GAPPEDPRIMARY 160uH
F30U60DN x8
WE
LDIN
GO
UT
PU
T-
+
FRONT PANEL
L1
KPOWERSWITCH M
JGAS SOLENOID240 VAC
FAN 240 VAC
10nF
1K
V
/SYNC
CT
OUTPUT
UNDER-VOLTAGE
LATCH
R
S
OSCILLATOR
Q
F/F
Q
/Q
S
5.0K
5.0K
LOCKOUT
REFERENCEREGULATOR
TO INTERNAL CIRCUITRY
ERROR AMP
PWM
SG3525A COMPENSATION
CSOFTSTART
VREF
VCC
SHUTDOWN
OUTA
OUTB
VC
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
RT
RD
DISCHARGE
V+MMBT5401 (2L)
MMBT5551 (G1)
V+
18
17
15
10
9
6
54
150Ω R1
4.7n
F C
10
5
SET1
D1
CLK1
CLR1
Q1
/Q1
VDD
VSS
SET2
D2
CLK2
CLR2
Q2
/Q2
534
6
2
1
12
138911
10
14
7
CD
4013
B
6
V+
7
8
LM3936
5
4
3
21
7
8
+VCC
-VCC
V+
GREEN LED - WELDING
3 4 YELLOW LEDOVERLOAD1 2
10KΩ R19
THERMAL CUTOFF(N.C. TO GND)
RED LEDPOWER
100KΩ R20
T.C. PULLUP
15K
Ω R
2347
KΩ
R24
V+
11 10 9 8
100K
Ω R
610
uF C
13
V+
XnF
C3
750KΩ R2
(SET @ 20.14KΩ 14:15)
XnF
C12
100Ω
R21
13 12
100KΩ R3
22nF C9
1R6 10Ω
15nF
1C
7
D7 D6
D3
D4 D
5
ELECTRODE OPEN VOLTAGEDETECT @ 49.7V
U1
U2
U3
U4U5
Q1
Q2
Q3
Q4
U3
U3 U3
U3
270KΩ R4
D2
D4
XnF C1
10uF
C5
V+
D1
D3
10K
Ω R
7
100Ω
R10
15K
Ω R
11
V+
2M2Ω
R9
V+
XnF
C6
VDD
VEEVSS
Y0A
Y1A
ZA
/E
14 11
10
9
6
54
3
21
12
13
78
16
15
SA
Y0B
Y1B
ZB SB
Y0C
Y1C
ZC SC
CD4053B
V+
U2
XnF C4
6K2Ω R8 100KΩ R22
4K7Ω R25 D5
1112134K7Ω R15
XnF
C2
10KΩ R16
15KΩ R17 15KΩ R18
4K7Ω R12 16
10uF
C7
6.8n
F C
8
47KΩ R13XnF C11
0
12
24
48
/WELDING
2.9V
80mV
633mV
V+
14
U37
ELECTRODE SENSE
J1
10uF 50V1C6
B3
144K7Ω R14
50K W1
32
1
V+VCC
GND
GND
J2
2KΩ
W2
15Ω 1R3
15nF 1C2
J3
15Ω 1R2
15nF 1C3
1KΩ 1R7
1D8 10nF 1C12
470u
F 4
00V
470u
F 4
00V
10nF
1K
V 1
C1
100Ω 1W 1R1
J3J5
240V
AC
20 A
10nF
1K
V 1
C10
K
M
220u
F 1
C17
D8
10KΩ R5
3KΩ 1R8
50KΩ R1
3KΩ R100
30nF 1C18
J
D1
D2
100n
F 1
C9
1000
uF 1
C8L7
812
100n
F 1
C13
1000
uF 1
C11
B2
(SE
T @
717
Ω)
2.4KΩ 1R9
PO
WE
R S
WIT
CH
FAN
TO GASSOLENOID
U4
IGB
TF
EE
D
PW
RIN
IRF
D11
0U3
P525G
IGB
T D
RIV
E
B2
E2
B1
E1
PWM FREQUENCY TRIM
HE
AT
- S
ELE
CT
HE
AT
- H
IGH
HE
AT
- L
OW
HEAT TRIM
CURRENTSENSE
-START
+START
V+
THERMALCUTOFF
IN
OU
T
GND
PWM CONTROL BOARD
MAC97A6 1U2
5.1Ω
1W
1R
45.
1Ω 1
W 1
R4
CD4069
MMBT5551 (G1)
MMBT5401 (2L)
POWER ONRESET
~2S
EC
TC
~1S
EC
TC
~0.
5SE
C T
C
~40
KH
Z O
SC
.
t1
t0
t4
t3
t0 t1 t3 t4
ST
AR
T H
EA
T
WE
LD H
EA
T
0: START 1: WELD
t2OPEN
WELD
IDLE
CONTACT
t2
GN
D
RE
DYEL
GR
N
GBPC3510 BD1
U5
1
2
3
B2
E2
B1
E1
E2
C1
C2
E1
SHADED BOX DENOTESCOMPONENT MOUNTEDTO HEAT SINK
HEAT - SELECT
HEAT - HIGH
HEAT - LOW
GND
GRN WELDING
OVERHEAT
POWER
J2
10K
Ω W
3
HEAT
10 MAX
1 MIN
HEAT CONTROL
2K2Ω
2K2Ω
2K2Ω
YEL
RED
OEM SCHEMATIC
2 of 4KENDE TIG WELDERAKA: HARBOR FREIGHT #91811
REV 0.6PAGEUNIFIED
Reverse IP by [email protected]. Modifications,Documentation, Copyright (c) 2008-2009 [email protected]
R1
R2
R3
R4
D1
C1
C2
C3
R5
R6
D2
D3
R7
C4
R8
R9
C5
C6
C7 C8 C9 C10 R10 R11
R12
R13
C11
R14
R15
R16
R17
R18
R19
D4
R20
R21
R22
R23
R24
R25
C12
C13
D5
Q1 Q2
Q3 Q4
U1 U2 U3 U4 U5
18 15 1417 10 9 6 5 4781116 1213 2 13
V+
GN
D
GN
D
ELE
CT
RO
DE
SE
NS
E
/WE
LDIN
G
(WE
LDIN
G)
GR
EE
N L
ED
(OV
ER
LOA
D)
YE
LLO
W L
ED
(PO
WE
R)
RE
D L
ED
T.C
. PU
LLU
P
TH
ER
MA
L C
UT
OF
F
HE
AT
- H
IGH
HE
AT
- S
ELE
CT
HE
AT
- L
OW
HE
AT
TR
IM G
ND
HE
AT
TR
IM IN
PW
M F
RE
QU
EN
CY
TR
IM
PH
AS
E A
DR
IVE
PH
AS
E B
DR
IVE
PWM CONTROL BOARD SMD COMPONENT MAP
10K
Ω
10K
Ω
1KΩ
~10
KΩ
PE
DA
L "U
P"
HE
AT
LIM
IT
PE
DA
L "D
OW
N"
HE
AT
LIM
IT
100n
F
PEDAL HEAT SELECT
100n
F
6
5
3
24
VCC
LM324-2
11
1
7
UP
DOWN
OU
T
V+
100n
F
UP
DOWN
V+
1KΩ
~10
0KΩ
V+
OU
T
100n
F
10uF
10K
Ω W
3
HEAT
10 MAX
HEAT - SELECT
HEAT - HIGH
HEAT - LOW
GND
1 MIN
J2WELDING
OVERHEAT
POWER
FRONT PANELHEAT CONTROL
PEDAL CONTROL
INTERNAL CONTROL
100n
F
VREF_LOW
VREF_HIGH
13
1414
9
108
LM324-1
LM324-3
LM324-4
V+
GND
TO WELDERMAIN BOARD
100n
F
100n
F
3 of 4KENDE TIG WELDERAKA: HARBOR FREIGHT #91811
REV 0.6PAGEUNIFIED
Reverse IP by [email protected]. Modifications,Documentation, Copyright (c) 2008-2009 [email protected]
10uF
U5.3U5.2
LM324-3 AND LM342-4 BUFFERHIGH/LOW HEAT LIMITS OFORIGINAL DIVIDER. PEDAL LIMITSDEFINE UP/DOWN RANGE WINDOWTHROUGH WHICH PEDAL HEATPOT SWEEPS
BUFFERING LINE TO WELDERFOR HIGH IMPEDANCE PEDALPOTENTIOMETER
PEDAL HEAT SELECT
EXTERNAL HEAT CONTROL MODIFICATION
/SYNC
CT
OUTPUT
UNDER-VOLTAGE
LATCH
R
S
OSCILLATOR
Q
F/F
Q
/Q
S
5.0K
5.0K
LOCKOUT
REFERENCEREGULATOR
TO INTERNAL CIRCUITRY
ERROR AMP
PWM
SG3525A COMPENSATION
CSOFTSTART
VREF
VCC
SHUTDOWN
OUTA
OUTB
VC
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
RT
RD
DISCHARGE
V+MMBT5401 (2L)
MMBT5551 (G1)
V+
18
17
15
10
9
6
54
150Ω R1
4.7n
F C
10
5
SET1
D1
CLK1
CLR1
Q1
/Q1
VDD
VSS
SET2
D2
CLK2
CLR2
Q2
/Q2
534
6
2
1
12
138911
10
14
7
CD
4013
B
6
V+
7
8
LM3936
5
4
3
21
7
8
+VCC
-VCC
V+
GREEN LED - WELDING
3 4 YELLOW LEDOVERLOAD1 2
10KΩ R19
THERMAL CUTOFF(N.C. TO GND)
RED LEDPOWER
100KΩ R20
15K
Ω R
2347
KΩ
R24
V+
11 10 9 8
100K
Ω R
610
uF C
13
V+
XnF
C3
750KΩ R2
(SET @ 20.14KΩ 14:15)
XnF
C12
100Ω
R21
13 12
100KΩ R3
22nF C9
1R6 10Ω
15nF
1C
7
D7 D6
D3
D4 D
5
ELECTRODE OPEN VOLTAGEDETECT @ 49.7V
U1
U2
U3
U4U5
Q1
Q2
Q3
Q4
U3
U3 U3
U3
270KΩ R4
D2
XnF C1
V+
D1
10K
Ω R
7
100Ω
R10
15K
Ω R
11
V+
2M2Ω
R9
V+
XnF
C6
VDD
VEEVSS
Y0A
Y1A
ZA
/E
14 11
10
9
6
54
3
21
12
13
78
16
15
SA
Y0B
Y1B
ZB SB
Y0C
Y1C
ZC SC
CD4053B
V+
XnF C4
6K2Ω R8 100KΩ R22
4K7Ω R25 D5
1112134K7Ω R15
XnF
C2
10KΩ R16
15KΩ R17 15KΩ R18
4K7Ω R12 16
10uF
C7
6.8n
F C
8
47KΩ R13XnF C11
0
12
24
48
/WELDING
2.9V
80mV
633mV
V+
14
U37
ELECTRODE SENSE
J1
10uF 50V1C6
B3
144K7Ω R14
50K W1
321
V+
GNDGND
J2
2KΩ
W2
15Ω 1R3
15nF 1C2
J3
15Ω 1R2
15nF 1C3
1KΩ 1R7
1D8 10nF 1C12
470u
F 4
00V
470u
F 4
00V
10nF
1K
V 1
C1
100Ω 1W 1R1
J3J5
240V
AC
20 A
GBPC3510 BD1
10nF
1K
V 1
C10
K
M
220u
F 1
C17
D8
10KΩ R5
3KΩ 1R8
50KΩ R1
3KΩ R100
30nF 1C18
J
D1
D2
100n
F 1
C9
1000
uF 1
C8
100n
F 1
C13
1000
uF 1
C11
B2
(SE
T @
717
Ω)
2.4KΩ 1R9
PO
WE
R S
WIT
CH
FAN
TO GASSOLENOID
U4
IGB
TF
EE
D
PW
RIN
IRF
D11
0U3
P525G
IGB
T D
RIV
E
B2
E2
B1
E1
PWM FREQUENCY TRIM
HE
AT
- S
ELE
CT
HE
AT
- H
IGH
HE
AT
- L
OW
HEAT TRIM
CURRENTSENSE
-START
+START
V+
THERMALCUTOFF
PWM CONTROL BOARD
MAC97A6 1U2
5.1Ω
1W
1R
45.
1Ω 1
W 1
R4
CD4069
MMBT5551 (G1)
MMBT5401 (2L)
~2S
EC
TC
~1S
EC
TC
~0.
5SE
C T
C
~40
KH
Z O
SC
.
4 of 4
t1
t0
t4
t3
t0 t1 t3 t4
ST
AR
T H
EA
T
WE
LD H
EA
T
0: START 1: WELD
t2
OPEN
WELD
IDLE
CONTACT
t2
GN
D
RE
DYEL
GR
N
/EX
T_S
EL
EX
T_H
EA
T
V+
GN
D
GN
D
ELE
CT
RO
DE
_CO
NT
AC
T10
KΩ
OC
V_D
ET
EC
T
10K
Ω
V+
KENDE TIG WELDERAKA: HARBOR FREIGHT #91811
REV 0.6PAGEUNIFIED
Reverse IP by [email protected]. Modifications,Documentation, Copyright (c) 2008-2009 [email protected]
D3
10uF C5
1KΩ
WE
LD_O
FF
POWER ON RESET
PW
M_S
HU
TD
OW
N
D4
OV
ER
HE
AT
_DE
TE
CT
/GAS_SOLENOID (DRIVE VIA OPEN COLLECTOR)
CURRENT SENSE
100n
F
T.C. PULLUP
V+
PHASE B DRIVE
PHASE A DRIVE
VR
EF
1KΩ
~10
KΩ
100n
F
PEDAL HEAT SELECT
V+
100n
F
PEDAL CONTROL
INTERNAL CONTROL
100n
F
6
5
3
28
VCC
LM35
8
4
1
7
UP
100n
F
EXTERNAL HEAT CONTROL
DOWN
OU
T
V+10
KΩ
10K
Ω4K
7Ω
10K
Ω10
KΩ
4K7Ω
PE
DA
L "U
P"
HE
AT
LIM
IT
PE
DA
L "D
OW
N"
HE
AT
LIM
IT
100n
F
ALTERNATE PEDAL HEAT SELECT(POTENTIOMETER VALUE NOT CRITICAL)
UP
DOWN
V+
1KΩ
~10
0KΩ
OU
T
100n
F
10uF
MODIFICATION OF WELDER TO PROVIDEFULL EXTERNAL CONTROL ACCESS(EXTERNAL HEAT SELECT SHOWN ASEXAMPLE USAGE)
L781
2IN
OU
T
GND
U5
2
3 1
EXTERNAL HEAT CONTROL
EXTERNAL TIMING CONTROL
EXTERNAL CIRCUITRY
FULL EXTERNAL HEAT/TIMING CONTROL MODIFICATION