I recently bought a 1981 Dan mig 140 mono. Like most guys on here I bought it cheap and not working. I got the trigger to activate the main relay, and the gas valve. But it doesn’t operate the wire feed motor. Any tips? Thanks
Hello friends, i purchased a dan-mig 140 today and found that it has an issue. I noticed someone has wired in an old extension cord to the machine with a push button on it. Performed a function test to find the wire feed motor operates like it should. However the main contactor does not close...
www.mig-welding.co.uk
It has links to other Dan-MIG threads here, and there is a copy the schematic diagram of the control board.
A TRIAC on that board feeds AC power to the Contactor and the gas valve. The wirefeed motor is controlled and braked by transistors, without a relay. It uses a 24v DC supply, which comes from a medium-sized auxiliary transformer and is fused.
The welder has a "semi-synergic" function, which increases the wire speed with each step in the welding voltage. Therefore the DC welding voltage also has to be present to enable the wirefeed motor. That should vary from about 14v to 30v at the torch tip, as you step up the power ranges.