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Added a contactor to my little mig

Posted: Wed Apr 04, 2018 8:37 pm
by Mike Westbrook
Added a military grade contactor to my hot all the time little mig unit was easier than I thought and works like a champ

Re: Added a contactor to my little mig

Posted: Wed Apr 04, 2018 10:49 pm
by Franz©
Different way of doing it, I usually go with air conditioning compressor contactors on the primary side. I get them free.

You might want to add a flux collapse supression diode across the coil of that relay to minimize arcing on the gun switch before you cook that.

Re: Added a contactor to my little mig

Posted: Thu Apr 05, 2018 8:55 am
by Mike Westbrook
I powered them off a separate power supply and a Bosch relay so I didn't Rob any voltage off the secondary all the parts are from military gen sets so they are rated 12 to 32 volts so I could use the welder power for the relay and then a little transformer to power the contactors they are battery isolation solenoids rated for continuous 400 amps only used two cause they were free !

Re: Added a contactor to my little mig

Posted: Thu Apr 05, 2018 1:57 pm
by Franz©
Noticed your location. Around Millersburg perhaps?

I'd still do the antispiking diode to protect the gun switch. It's probably only a cheap Cherry microswitch if that. You ain't going to be happy if it welds itself shut.

Re: Added a contactor to my little mig

Posted: Thu Apr 05, 2018 7:25 pm
by Mike Westbrook
Little closer to Gettysburg that's the main reason I like that welder it actually welds nice with .025 and gas plus the tweco mini mig gun fits anywhere great for body work and sheet metal

Re: Added a contactor to my little mig

Posted: Thu Apr 05, 2018 9:33 pm
by Franz©
Mike Westbrook wrote:Little closer to Gettysburg that's the main reason I like that welder it actually welds nice with .025 and gas plus the tweco mini mig gun fits anywhere great for body work and sheet metal
Thought maybe you were over by Coleman's giant collection of surplus toys.

Since you're building the machine are you putting a gas valve in too?

Re: Added a contactor to my little mig

Posted: Thu Apr 05, 2018 9:38 pm
by Mike Westbrook
Franz[COPYRIGHT SIGN] wrote:
Mike Westbrook wrote:Little closer to Gettysburg that's the main reason I like that welder it actually welds nice with .025 and gas plus the tweco mini mig gun fits anywhere great for body work and sheet metal
Thought maybe you were over by Coleman's giant collection of surplus toys.

Since you're building the machine are you putting a gas valve in too?
I know Coleman's the machine came with one flux or gas always ran with gas

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Re: Added a contactor to my little mig

Posted: Thu Apr 05, 2018 9:41 pm
by Mike Westbrook
Here's one of my other projects this one took 6 months until I was pretty happy with it

Re: Added a contactor to my little mig

Posted: Thu Apr 05, 2018 9:50 pm
by Franz©
Unfortunately I'm 4-5 hours from Coleman's Toys - R- Us yard.

Charlie has many wonderful toys at decent prices.

Cute project box. Did you put HiFreq on it too?

Re: Added a contactor to my little mig

Posted: Fri Apr 06, 2018 6:58 am
by Mike Westbrook
Sure did Tesla style from a oil burner trans with a basic triac power control for arc force machine was a tombstone added a double bridge rectifier huge DC inductor 15000 watt scr for power control internal gas valve and built a five pin style pedal it actually works really great kind of a tig250/250 on a budget

Re: Added a contactor to my little mig

Posted: Fri Apr 06, 2018 2:56 pm
by Franz©
there was a time when Linkoon and Miller Bros both marketed a tin box with some of that component structure in it. I think Forney did too. Triacs and SCR didn't exist yet so they used relays.
HV transformer for the HiFreq resembled an old TV flyback transformer, and needed cleaning occasionally because it precipitated plenty of dust & smoke.