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Input on cheap stick power supply please.

Miguels244

Diamond
Joined
Mar 27, 2011
Location
Denver, CO USA
I'm looking for a cheap stick power supply.
200A class, 220v single phase input.
High duty cycle.
I'm using it for a non welding application and don't need any fancy controls.
Just current, efficiency and duty cycle...so I'm not spending a grand on a welder supply.

There are dozens of cheap asian units out there, any input on which might work well?
Other suggestions?
 
Gotta realise your duty cycle requirements will push you out of the cheap Asian class machines. Oftern a 200amp welder has a 10 minute duty cycle of 40% at best (yes 4 minutes on out of every ten, not anything like 20 minutes on in a hour). If you want 100% at 200amps your going to have to go a lot lot bigger to get it, nature of the beast with arc welding, its a very stop start process, so even a real 60% duty cycle barely ever impacts actual stick welding productivity. Rough guess you probaly need a 300 amp plant if you want it actually outputting 200amps for more than 15 minutes straight.

Large, second hand oil cooled is probably more like what you really want on a cost - duty cycle - amp supply basis.
 
Uweld.biz has the big yellow 220 volt 200 amp unit for $700. I've had good luck with it. He Imports them, tests them, and fixes anything that's wrong before he sells them. He's up by Milwaukee, but he also ships.
 
Look for a big mfr'ing/welding facility auction, they usually have some big old units that sell pretty cheap, but will most likely be 3 phase. If you need 100% duty cycle, you most likely will need a 400 amp unit that can loaf along at 200 amps.
 
so you need constant current , not constant voltage ?

Mig C.V. power supplies can be found for around $200-300 ,are 100% duty cycle @ rated output -but will be 3 phase .

200A @ 220v single phase C.C. and 100% duty cycle is basically a 350A @40% machine .

i find it unusual that you would have the line amperage to run such a welder continuously, but not have 3 phase .
 
You can probably just stack up a bunch of Chinese LED power supplies to get to that power level. I assume you need 24V or so, and that constant voltage will be fine (you can rewire them to behave differently and to gang together properly, but it takes a little know how) in which case a single 350W supply is $20 and outputs 14 amps. 15 power supplies only cost $300, for 100% duty cycle if you put them in a ventilated enclosure and don't cluster them too close together.

I assume you are generating hydrogen or doing something similar, in which case this wouldn't be any worse of an idea than a welder. I'm almost positive the supplies have enough droop at full load to balance themselves well enough. I would personally make a new feedback loop for them using an op amp to add the supply current to the average voltage of all supplies, which will regulate the voltage and power distribution. Or use a low value resistor, or just buy two and dick around with trimmer pots until you get them to split a load.
 
I find it unusual that you would have the line amperage to run such a welder continuously, but not have 3 phase .

200 amps at 25 volts is only 23 amps at 220 volts. Of course welders are nowhere near perfect efficiency, but a typical 50 amp outlet would be no problem at all.
 
^ You don't even need that over here 32 amp at 240V sockets are common, my 200 amp AC/DC inverter TIG draws circa 26 amps at 200 amp output.
 
so you need constant current , not constant voltage ?

Mig C.V. power supplies can be found for around $200-300 ,are 100% duty cycle @ rated output -but will be 3 phase .

200A @ 220v single phase C.C. and 100% duty cycle is basically a 350A @40% machine .

i find it unusual that you would have the line amperage to run such a welder continuously, but not have 3 phase .
Home use.

^ You don't even need that over here 32 amp at 240V sockets are common, my 200 amp AC/DC inverter TIG draws circa 26 amps at 200 amp output.
I know...us electricity is pretty wimpy.
 
You can probably just stack up a bunch of Chinese LED power supplies to get to that power level. I assume you need 24V or so, and that constant voltage will be fine (you can rewire them to behave differently and to gang together properly, but it takes a little know how) in which case a single 350W supply is $20 and outputs 14 amps. 15 power supplies only cost $300, for 100% duty cycle if you put them in a ventilated enclosure and don't cluster them too close together.

I assume you are generating hydrogen or doing something similar, in which case this wouldn't be any worse of an idea than a welder. I'm almost positive the supplies have enough droop at full load to balance themselves well enough. I would personally make a new feedback loop for them using an op amp to add the supply current to the average voltage of all supplies, which will regulate the voltage and power distribution. Or use a low value resistor, or just buy two and dick around with trimmer pots until you get them to split a load.

Arc melting foundry.
I could just go with a big ass full wave rectifier and an SCR chopper.
And very well might.
Easy enough to control the current loop with the SCR.
Not sure what having that high an OCV would do to the system.

The arc voltage is cntrolled by closing the loop around the electrode position.

The main reason I’m looking at a welder is frequency and the fact the guy I’m trying to copy uses one so I know it works.

Oh, and a transformer alone is a few hundred bucks plus shipping.
 
Arc melting foundry.
I could just go with a big ass full wave rectifier and an SCR chopper.
And very well might.
Easy enough to control the current loop with the SCR.
Not sure what having that high an OCV would do to the system.

The arc voltage is cntrolled by closing the loop around the electrode position.

The main reason I’m looking at a welder is frequency and the fact the guy I’m trying to copy uses one so I know it works.

A high OCV could either help with starting if you have no capacitors, or make it very difficult if you have a lot of capacitors.

And SCR chopper wouldn't be too bad if you can handle the electrical noise and nonisolation.
 
200 amps at 25 volts is only 23 amps at 220 volts. Of course welders are nowhere near perfect efficiency, but a typical 50 amp outlet would be no problem at all.

you are assuming inverter. older transformer supplies aren't as efficient . my cp-252ts pulls a max of 32A @220v 3ph.
ican't translate to single phase .... but it's more than 32 Amps
 
you are assuming inverter. older transformer supplies aren't as efficient . my cp-252ts pulls a max of 32A @220v 3ph.
ican't translate to single phase .... but it's more than 32 Amps

That translates to 55 amp single phase, for what I presume is more than a 200 amp peak output, so I'm not too far off.
 
According to this, the 100% rating is 230 amp at 29 volts

Tom

Edit: I agree with you. The manual says 60%. Looking at the wiring diagram, The weak sister appears to be the input rectifier. Replacing that with a larger single phase bridge?

T:-
 

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According to this, the 100% rating is 230 amp at 29 volts

Tom

Edit: I agree with you. The manual says 60%. Looking at the wiring diagram, The weak sister appears to be the input rectifier. Replacing that with a larger single phase bridge?

T:-

I wonder how low the current can go.
If I buy that power source I should buy a PAW box too.
I’m not interested in heavy welding, I’m more interested in small stuff.
Supposedly PAW gets lighter than TIg.
But I don’t know about welding at all.
 
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