Welder project, need a capacitor

[Ogrebonz]

Can anyone tell me where I can find a cheap source for a 50v DC 46k micro-farad (or larger, up to 300k mfd) capacitor? I'm talking under $15.00.

I need one for a welder mod I'm working on and Amazon and EBay are giving me grief.

 

[MoparManiac]

Digi-key?

I wouldn't rely on ebay or amazon for small parts like that.

Fortunately I had a local place near me that sold a lot of that stuff. I went there a few times while modifying my MS2 ECU.

 

[iluv83vettes]

My little Lincoln from HD had the capacitor go out (of course it was a couple weeks out of warranty) and I looked and looked for one but couldn't find one.

 

[souske]

Dunno about the specific cap a you are asking for, but the last surplus center catalog had a bunch of used caps cheap

 

[old_man]

I'm a EE. Tell me a bit about the circuit? Not all caps are the same, even with the voltage and capacity.

 

[Ogrebonz]

I'm switching my little HF AC flux core from AC to DC with a bridge rectifier. I'm definetly not an EE, but I understand that a capacitor is needed to absorb the spikes.

 

[old_man]

You are going to need a very large bridge rectifier. You need a DC type capacitor. It needs a fair amount of capacity and needs to handle a large amount of ripple current. I will check around and see what I can find. $15 actually sounds fairly cheap. If you get a cap with out what is called low ESR, it may work for a while, then explode, taking out the bridge and possibly starting a fire.

 

[Ogrebonz]

https://www.youtube.com/watch?v=NoYN4vx1WU8

Here's where I got the idea.

 

[kastein]

Look on ebay for caps out of old medical equipment in the business and industrial section. I and some friends have built a number of fairly large capacitor banks for high energy experimentation (plasma thrusters, eddy current launchers, railguns, etc) and that's where we usually get our caps. Pulse rated is a plus but I am not sure you need that.

If you can't find any there, try digikey like MoparManiac said, mouser, jameco, bgmicro has good stuff cheap occasionally, electronics goldmine, and allied/newark if the others don't stock what you need.