Hi Guys,
Before I start, great forum, I've been reading for a couple of weeks and learnt quite a bit, thanks.
I've aquired an old 150A Migatronic, HP5000 I think the model is, I need to get back into the garage to check that though.
It has a problem. It has a 4way switch on the front panel for current which switches between the different primaries of the main transformer. I guess this is normal practice ? This all works fine, I can see 230v being applied to the different windings, the switch is clean and functional. The neutral of the primary is fine also. 230v measured on the transformer contacts themselves.
But, there's bugger all current from it, you couldn't weld 2 sheets of tin foil together!
I stripped and checked the rectifiers, doides are fine and everything is connected as it should.
The secondary of the transformer measures 20v-0v-20v AC with the welder set to max current. This results in about 23vdc at the torch with the trigger pressed. This seems low to me, I thought I should see maybe 40v or so ?
I checked for volt drop and continuity on all other connections, the earth lead right back upto the rectifier etc. All good. I tried a different torch too.
I came to the conclusion that the transformer must have an issue, but I'm finding it hard to believe ? Am I barking up the wrong tree ? I thought it's either going to work or not! the primaries I guess are fine because current does increase as you click up through the 4 ranges but all are v.low, so maybe a problem in the secondary winding ??
Could old/dried out smoothing capacitors in the DC side cause the same problem ? I figured probably not!
Any help or advice would be much apreciated before I go hunting for a transformer I can use.
Many thanks, Chris
Before I start, great forum, I've been reading for a couple of weeks and learnt quite a bit, thanks.
I've aquired an old 150A Migatronic, HP5000 I think the model is, I need to get back into the garage to check that though.
It has a problem. It has a 4way switch on the front panel for current which switches between the different primaries of the main transformer. I guess this is normal practice ? This all works fine, I can see 230v being applied to the different windings, the switch is clean and functional. The neutral of the primary is fine also. 230v measured on the transformer contacts themselves.
But, there's bugger all current from it, you couldn't weld 2 sheets of tin foil together!
I stripped and checked the rectifiers, doides are fine and everything is connected as it should.
The secondary of the transformer measures 20v-0v-20v AC with the welder set to max current. This results in about 23vdc at the torch with the trigger pressed. This seems low to me, I thought I should see maybe 40v or so ?
I checked for volt drop and continuity on all other connections, the earth lead right back upto the rectifier etc. All good. I tried a different torch too.
I came to the conclusion that the transformer must have an issue, but I'm finding it hard to believe ? Am I barking up the wrong tree ? I thought it's either going to work or not! the primaries I guess are fine because current does increase as you click up through the 4 ranges but all are v.low, so maybe a problem in the secondary winding ??
Could old/dried out smoothing capacitors in the DC side cause the same problem ? I figured probably not!
Any help or advice would be much apreciated before I go hunting for a transformer I can use.
Many thanks, Chris