Theory of operation, High voltage / high frequency circuit – Lincoln Electric SQUARE WAVE TIG 255 SVM100-A User Manual
Page 36
SQUARE WAVE TIG 255
E-3
THEORY OF OPERATION
HIGH VOLTAGE / HIGH FREQUENCY CIRCUIT
LINE
SWITCH
R
E
C
O
N
N
E
C
T
MAIN
TRANSFORMER
X2
X1
POWER
FACTOR
CAPACITORS
FAN
115VAC
PROTECTION
SNUBBER
BOARD
ARC START
115 VAC
GATE SIGNALS
HI-FREQ
115 VAC
CONTROL
BOARD
LCD DISPLAY
KEYPAD
LED
BOARD
KEYPAD
HIGH VOLTAGE
TRANSFORMER
CIRCUIT
115 VAC
115 VAC
REMOTE
RECEPTACLE
115 VAC
RECEPTACLE
CONTROL
TRANSFORMER
24 VAC
18 VAC
16 VAC
HIGH FREQUENCY SPARK
WORK
ELECTRODE
HI-FREQ
TRANSFORMER
BY-PASS
BOARD
POLARITY
SWITCH
CHOKE
FEED BACK
GATE SIGNALS
AC
AC
DC+
DC-
SCR
BRIDGE
SHUNT
The control board passes the 115vac through the pro-
tection / snubber board to the primary of the high volt-
age transformer. The secondary of the high voltage
transformer is coupled to a spark gap generator and
also to the high frequency transformer. The high fre-
quency transformer transfers the high frequency
“spark” to the electrode stud.