Lincoln Electric SVM146-A service manual Table of Contents Theory of Operation Section

Return to Master TOC

Return to Master TOC

Section E-1Section E-1

TABLE OF CONTENTS

-THEORY OF OPERATION SECTION-

Theory of Operation	Section E
General Description	E-2
Input Line Voltage, Contactor and Main Transformer	E-2
Precharge and Protection	E-3
Main Transformer	E-4
Output Board and Torch	E-5
Control and Display Boards	E-6
Protection Circuits	E-7
Overload Protection	E-7
Thermal Protection	E-7
Insulated Gate Bipolar Transistor (IGBT) Operation	E-8
Pulse Width Modulation (PWM)	E-9
Minimum Output	E-9
Maximum Output	E-9

FIGURE E.1 – PRO-CUT 80 BLOCK LOGIC DIAGRAM

Return to Master TOC

INPUT
LINE	INPUT
SWITCH	RECTIFIER
	AIR
	PRESSURE
	SWITCH
	"A"

POWER BOARD

CR 1&2

RELAY

IGBT

CAPACITOR

R

EIGBT

C

O
N
N
E
C		IGBT
T			CURRENT
S			TRANSFORMER
W
I	CAPACITOR
T
C
H
		IGBT

P
R
O
T	CR 1	& 2	IGBT
E	RELAY
C			GATE
	DRIVE
T			SIGNALS

MAIN

TRANSFORMER

TRIGGER & SAFETY

		WORK
		NOZZLE
	ELECTRODE
		TORCH
OUTPUT	BOARD	CONNECTOR
		E
		L
		E
		C
		T
		R
		O
		D
		E
	CHOKE	S
	PILOT	O
TRANSISTOR		L
		E
		N
		O
		I
		D
	TRIGGER & SAFETY
		AIR
		SOLENOID
		REMOTE
		INTERFACE
		RECEPTACLE

Master TOC

L

E

A

D

I			SIGNAL
O
N	SIGNAL
				CONTROL BOARD
	18/36VAC
				R	A	T	S
				E	I	H	A
		THERMOSTATS		A	R	E	F
					L	R	E
				D		M	T
				Y	O	A	Y
					W	L

OUTPUT CONTROL

DISPLAY BOARD

ELECTRODE & TRANSFER

CURRENT FEEDBACK

PILOT ENABLE

ELECTRODE SOLENOID ENABLE

AIR SOLENOID ENABLE

12VAC

24VAC

Return to

115VAC

AUXILIARY

TRANSFORMER FAN

MOTOR

PRO-CUT 80