Hacking a welder?

[jrz126]

Hi gang,
I was just up at salvage here at work, and I came across a couple of arc welders (stick). They are good sized units (probably 100% duty cycle), but they are 3 phase unfortunitly. I was wondering, is there anything useful inside there? I think it might be capable of DC, so there are probably some diodes and stuff.

I'd be paying $0.25/lb for it, so it'll be a good price.

 

[Someone Electro]

Dont you in your country have 3 phase mains outlets in homes?

Ok you will find an huge transformer that is capable of outputing up to meany kW ,an diode bridge capabe of 100s of amps and big capacitor some powerful switches...

Not realy useful stuff.

I think you can get an normal mains to 3 phase adaptor for a welder.The welder will have much less power.We once used such an thing but the problem was the 16A circuit breaker kept triping about evry 5 minutes.

 

[MARINE1142]

Well if it is not a dc welder all there will be in there would be a transformer and a shunt to change the amp's but if it is a dc machine then hes you would find some high amp diodes and caps to filter depending on the year the machine and model of machine there might be some other good parts in there such as contactors relays small simple boards etc. Also if the machine is really old the transfomer is made of copper it might be worth more as scrap copper?

 

[stevez]

I used to grab on to just about any kind of junk with electronics inside but have learned a few things. This was "free" junk, not something I'd have to pay for. Where I came out:

1. The junk takes up space - ok if you've got lots of it but most people are space limited. At some point you can have so many useful things that you can't find any of them - at which point most all of it is no longer useful.

2. Junk you have to pay for ties up your money. You might pay $25 for the welders and it's $25 you don't have to buy something else.

3. Items purchased new are usually pretty reliable, have specs, sometimes a warranty, etc. Something used could have faults and you may be lacking specs or parts identification. The odds are good that you won't be sure of what you've got and whatever it is might be bad. Worse yet is you use the parts in something then struggle only to eventually learn the parts were bad.

4. It will take some of your time to extract or recover the items or components. If you add that to #1, #2 and #3 you have space, time and money tied up in something that might be what you want and might or might not work.

Sorry for being so negative but I've eased off myself on the collection of things. The welders might be good if you can fix them or you know they have the parts you'll need for a specific project. On the other hand, if they were going to cost you $25 you might give some thought to the cost of the parts you might extract from them. The diodes you might recover certainly could be useful but if you were using them in a non-critical application you might be able to get the diodes new for a lot less.

What I do now with electronics - I might grab a power supply from a computer that is being discarded but only if I know my next step is to open it up and quickly extract the large caps, power resistors, marked power transistors and inductors. I can test those things and they are useful for experimenting. The rest goes back. I don't save the board with the hundreds of parts on it. I know I won't take the time later on to search. I use the space I save for an organized parts collection. While not as impressive I can find the stuff quickly.

 

[Someone Electro]

My grandpa workd in elektroteha an they made mostly mains motors.So he got lots and lots of motor coils some even have up to 1,5 mm thick coper wire.

geting such an huge an transformer apart cod spell problems.(watch that you dont drop it on your foot.LOL)

TVs and radios are good things to take a part.

Modern electronics (especialy digital) dont make an good componnet source since there mostly made from tiny SMD components.

 

[chemelec]

Before Buying it, I would determine if it was Copper or Aluminum Windings.

Than:
1) If it is Copper?
2) If you actually could make use of a Welder?
3) If you have the Skills, Knowledge and Time to Rebuild it?

Than Buy it.

If its Aluminum Windings,,,,,,,Forget It.

 

[panic mode]

Dont you in your country have 3 phase mains outlets in homes?

Unfortunately no, I was shocked too... :?
In North America three pase power is reserved for industrial buildings, residential get single phase of 2x120V (like center tap from a transformer).
Guess what happens with your appliances when the fault is on neutral conductor...
I've seen it in my kitchen when the boombox died. :evil:

 

[jrz126]

I dont really need the welder...I already have a nice Mig, and a crappy stick welder.
I just thought that it might be of use for some sort of cool HV project.

 

[Someone Electro]

grandpa uses 3 phashe motors from an factory in wich he worked and it was closed down.

he had one huge motor that is 5kW i think.

And 3 phase here is 380V

 

[ante]

Hi Jeff,

Welders with aluminium windings are very rare but there are some out there! I don’t think you will find much in this type of welder for a HV project. If they are cheap or free and not very outdated I would repair them and sell them, this could pay for some HV parts! 8)