Lincoln Electric SVM100-A service manual AC Welding Output, AC Welding Circuit

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

E-5 THEORY OF OPERATION

AC WELDING OUTPUT

			POLARITY SWITCH					BY-PASS
								BOARD
				(AC POSITION)
								WORK
								HI-FREQ
								TRANSFORMER
LINE								ELECTRODE
	MAIN
SWITCH
TRANSFORMER
R	X2		AC		DC+
E						SHUNT
				SCR
C
				BRIDGE
O
N
N
E	X1		AC		DC-
C						CHOKE
T
		SIGNALSGATE
POWER								FEEDBACK
FACTOR
CAPACITORS
				ARC START				LCD DISPLAY
	115VAC	PROTECTION		115 VAC		CONTROL		KEYPAD
FAN
		SNUBBER		GATE SIGNALS		BOARD		LED
		BOARD						BOARD
					HI-FREQ			KEYPAD
					115 VAC
		115
		VAC			24 VAC
				CONTROL		18 VAC
	115 VAC			TRANSFORMER
						16 VAC
RECEPTACLE
		115 VAC				HIGH VOLTAGE	HIGH FREQUENCY SPARK
						TRANSFORMER
	REMOTE
						CIRCUIT
	RECEPTACLE

By rotating the polarity switch to the AC position the	to the other AC side of the bridge. The choke is now
welding power circuit is changed. One lead (X2) of	electrically across the negative and positive SCR
the main transformer secondary is connected to the	bridge connections. Due to the ability of the choke to
machine’s output work stud. The other secondary	store energy and the SCR’s ability to turn on at the
lead (X1) is connected to one of the AC connections	appropriate times, an AC Square Wave is developed
on the SCR bridge. The electrode stud is connected	and applied to the output studs.

Return to Section TOC

Return to Master TOC

PRIMARY 1Ø

G CHOKE

G

G

G

AC WELDING CIRCUIT

ELECTRODE

AC

WORK

SQUARE WAVE TIG 255