-- 8 --
cmek2de1
2 2--stroke / 4--stroke
cmek2e08
2--STROKE
When SW1 is open, the unit operates in 2--stroke mode. Operating the trigger on the
welding torch starts the motor, opens the gas valve and energises the power unit
contactor.
Releasing the trigger stops the m otor, de--energises the contactor and closes the gas
valve. If burn--back is in operation, welding ceases when the burn--back time has
elapsed.
4--STROKE
When SW1 is closed, the unit operates in 4--stroke mode. Operating the trigger on
the welding torch opens the gas valve: releasing the trigger then starts the motor and
energises the power unit contactor.
Operating the trigger switch for a second time stops the m otor and de--energises the
contactor in the power unit: releasing the switch then closes the gas solenoid valve.
If burn--back is in operation, welding ceases when the burn--back time has elapsed..
3 Start / Stop
cmek2e07
The welding torch switch is supplied with 42 V AC. Closing the switch activates
optocoupler IC1, causing the voltage across C35 to go low.
