Lincoln Electric SVM132-A service manual General Description, Power Input Circuits

to Section TOC

to Master TOC

E-2

THEORY OF OPERATION	E-2
FIGURE E.1 – POWER INPUT CIRCUITS

Return

Return to Section TOC

Return

Return to Master TOC

REMOTE￿

OUTPUT￿

CONTROL

	#21
#75￿						WIRE FEED￿
#76￿
						SPEED CONTROL
#77
					CIRCUIT￿
					BREAKER
INPUT￿		#32					#32A
RECEPTACLE	#31
#2￿
&￿				2 OHMS
#4￿
￿
C￿
O￿
N￿
T￿
A￿
C￿			#531
T￿
O￿
R
CONTROL
		OPTIONAL￿
		BURNBACK￿
		BOARD
							GLP

VARIABLE VOLTAGE￿	#567	ELECTRODE￿
BOARD		METER￿
		SHUNT

CONTROL￿	ARMATURE	WIRE￿	THERMAL￿
		FEED￿	CIRCUIT￿
BOARD		MOTOR	BREAKER

#3￿

2￿

A

FUSE FIELD

RELAY￿

BOARD

GUN￿

CABLE￿

RECEPTACLE

REED￿	TRIGGER￿	WIRE￿	INTERLOCK	￿
		FEED￿
SWITCH	TRANS.		SWITCH
		SWITCH

Return to Section TOC

Return to Master TOC

GENERAL DESCRIPTION

The LN-8 is a semiautomatic wire feeder designed for Innershield (FCAW) and gas metal arc processes with the appro- priate accessories. It is also suitable for constant voltage (CV) submerged arc welding processes. With the optional variable voltage board installed the LN-8 can be used with constant current (CC) procedures. The wire feed speed and welding power source output can be controlled from the LN-8.

receptacle, through the circuit breaker and 2 ohm resistor to the control board, the relay board, and the trigger trans- former.

The 24VAC developed at the trigger transformer is rectified on the relay board and applied to the gun trigger cir- cuit which controls the 1CR relay.

The 115VAC that is applied to the con- trol board is rectified and controlled by SCRs (See SCR Operation) and applied to the armature of the wire feed motor.

Return to Section TOC

Return to Master TOC

POWER INPUT CIRCUITS	The relay board rectifies the 115VAC
	and applies it to the field winding of the
The 115VAC is applied (usually from the wire feed motor.
welding power source) via the input

NOTE: Unshaded areas of block logic diagrams are the subject of discussion.

LN-8