Return to Section TOC

Return to Master TOC

E-5

E-5

THEORY OF OPERATION

FIGURE E.5 – MODE SELECTOR AND OUTPUT CONTROLS

MULTI-WELD 350 BLOCK LOGIC DIAGRAM

to Master TOC

+

DC

POWER SOURCE

(EXTERNAL)

_

INPUT

 

 

LEFT AND RIGHT

 

DIODES

INPUT

CHOPPER MODULES

 

 

 

 

 

 

CONTACTOR

 

 

 

 

 

CR1

 

 

 

 

 

 

IGBT

 

FREEWHEELING DIODE

 

 

 

CHOPPER MODULE

 

 

 

INPUT

 

 

CHOKE

 

 

 

 

 

 

CAPACITORS

 

 

 

 

ON/OFF

 

IGBT

 

FREEWHEELING DIODE

 

MODE

 

 

 

 

 

SWITCH

20

CHOPPER MODULE

 

 

(1/2)

 

 

VDC

 

ON/OFF

VOLTS AMPS

 

 

 

 

 

x 2

 

MODE

 

 

 

 

 

SWITCH

 

 

 

 

 

(1/2)

 

 

 

 

 

GATE

 

 

 

 

ANALOG

SIGNALS

 

 

DC

40

 

WELD

 

BUS

VDC

CONTROL VOLTAGES

CONTROL

 

 

 

 

REGULATED

 

 

POWER

 

POWER

FAN

BOARD

 

SUPPLY

 

SUPPLY

 

 

 

 

 

 

BOARD

 

BOARD

 

 

TO ELECTRODE

CABLE

SHUNT+

CURRENT FEEDBACK

TO WELD CONTROL BOARD

REMOTE

RECEPTACLE

CCSLOPE

(STICK/GOUGE or PIPE)

Return

Section TOC

Return

Master TOC

40 VDC

ARC OUTPUT

HOT

 

15 VDC

THERMAL

FORCE

CONTROL

START

LIGHT

 

CONTROL

 

 

 

 

 

CR1

 

 

 

 

COIL

 

 

 

PERIPHERAL

 

 

 

 

BOARD

INDICATOR

 

 

 

INPUT

 

 

 

 

LIGHT

 

 

 

-

WORK

MODE SELECTOR AND OUTPUT

CONTROLS

Return to

Return to

In CC mode, machine output is at open circuit voltage. The OUTPUT control presets amps in the 30 to 350 A range and then adjusts actual welding current to match the preset when welding. In CV mode, machine output is at the voltage level set at the OUTPUT control. The OUTPUT control presets volts, then adjusts the actual arc voltage to match the preset when welding.

A HOT START control is provided to enhance arc start- ing with an adjustable output “boost” in either CC or CV mode. The ARC FORCE control (CC mode only) pro- vides extra weld current to prevent electrode “stubbing” An additional CC SLOPE switch improves “fast-freeze” stick electrode performance during vertical pipe weld- ing when set to the PIPE position.

Return to Section TOC

Return to Master TOC

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

MULTI-WELD 350

Page 35
Image 35
Lincoln Electric SVM151-A service manual Figure E.5 Mode Selector and Output Controls