Thread: Capacitor info required, any help would be appreciated.

Hi Crocy,

Any chance of a picture showing the markings and a picture might help narrow down the package type.

Here's a 0.002uF 6KV, does it look like this one?

S202M75Z5UU83L0R Vishay BC Components | 1269PH-ND | DigiKey

If that part was all you needed, I order stuff from Digikey every week, so I can tack it onto the next order, otherwise you'll get caught up on minimum order size.

Regards
Ray

Hi Crocy,

Can identify which part you are chasing in one of the attached manuals

https://www.woodworkforums.com/attach...hf-700005-.pdf

https://www.woodworkforums.com/attach...ing-manual.pdf


If it's the one I'm thinking of, then it will be a paper film foil type like this series http://www.cde.com/catalogs/T.pdf


Regards
Ray

Ray,
The HF cap (with the studs) is part 10 on page 10. I have a similar vintage TransTig 250 and the cap in mine is similar/the same as the 180. Here is a pic of the cap from the 250 manual.
hfcap.jpg

Here is the circuit. It's 1C - 0.002uF 3kV.

hfcircuit.jpg

Hi Vernon,

From the look of it, that's a paper oil capacitor, so you'd be looking for 0.002uF , or 2nF or 2000pF 3Kv or better paper/oil, I'd expect a 2.2nF would work just as well.

I'll go see what I can find.

Regards
Ray

I thought I could read "mica" on the capacitor in the 250 manual. The slight change of capacitor value would only marginally effect the frequency of the circuit, which I would image isn't terribly critical.

Hi Vernon,

Just looking at the picture it looks like 0.002 MF, does that possibly mean it's 0.002 milliFarad, which would make it 2 uF Edit: see next post.

If that's correct then maybe something like this would do?

KBG-P 4KV 2uF RUSSIAN MILITARY HIGH VOLTAGE CAPACITOR | eBay

Or http://www.cde.com/catalogs/HV.pdf Part number would be HVDMAS2J491B for 2uF 3Kv

Regards
Ray

Hi Vernon, Crocy

I've changed my mind, the one you want is this.

Capacitor 002 uf 5KV Transmitting Mica Ham Radio Tesla Coil | eBay


0.002 uF 5Kv Mica

Regards
Ray

Originally Posted by RayG

Capacitor 002 uf 5KV Transmitting Mica Ham Radio Tesla Coil | eBay

That sure looks like the ones I have seen.
One tip, you want to keep the top of the cap clean enough dusts and you get an arch across the terminals that eats the top of the cap away.
At least thats thats the story the engineers came up with to explain the deep groove between the terminals.

Stuart

I would send them an email querying that delivery price. They will probably repack it in a bag and send it a lot cheaper than that.

Ray, Vernon, Stuart and Bob. Thanks for all your help with this. Lost the hard drive again (when will Cliffie come back to Townsville) so have been offline, went to the internet cafe, but could not remember my password so could not reply. I decided to ask a guy at the Uni for help, and he recognised it as a Tesla coil circuit, rather primitive he said, but easy to fix and otherwise reliable. He took me on some searches of Tesla coil sites, and they explain what is required of the capacitor and he steered me to a site called (cant insert link) Information Unlimited, section, Tesla Accessories & Books, Page 3 and 4, where there are numerous purpose built capacitors for this application. I will try and get the one you found, but if not I will get one of these. Trying to decide if I should join all the welding forums, and let them all know as well, as there are a lot of these machines out there.
Any way, thanks again guys,
regards,
Crocy.

Hi

try also to get a capacitor of similar size with screw terminals.

This allows easy reconnection and insulation of existing cables etc in a (moderately) high voltage situation.

That eBay block type is what you need.
The cap value can be +/- 30%, but keep to the voltage rating or higher.

The suggested ceramic and other types will work, but it is the practical connection things which will make replacement easy for you.

You will most likely find that an old block mica type is best, and available, as millions were made, and they are stable with old age, and normally don't go leaky in the smaller values. Here is a case where age is not a problem.

If you cannot find a suitable capacitor, come back and tell us. Someone here will have one somewhere in their junkbox.

cheerio, mike

Thanks for the answer Mike, I have had feelers out everywhere when I read what the others had replied, but I will buy the 1 on ebay, as I am getting desperate to get the machine going again, to do some repairs on my mates Dragster. It must be my lucky day, as the repairer just rang, and my Plasma cutter is going again, so I can at least start cutting all the ally plate up ready.
thanks and regards,
Crocy

Hi Crocy

sounds good.
When you get it, wipe the cap down with metho, especially on the top between the terminals. While you are in there, also wipe all the high voltage cables and stuff with metho on a rag. or metho on a small paint brush, and let it all dry (sparks + metho = trouble).

Don't spray it with anything.
These things are not polarised.
Sangamo made high quality stuff, but if it is suspect it is leaky, you can test it with a megger or electrician's type electrical resistance checker at 1000V test.

After it is installed, and with the welder casing off, always assume that it is live, even when turned off, and always short the terminals out every time before working around it. A residual HV charge probably wont kill you, but may catch you by surprise, and you then might fall off a chair and hurt yourself.

I am curious as to how you determined that this capacitor was at fault and not the other components?

Now that you have tweaked our interest, tell us how the project goes please.

I somehow doubt if that type of welder would now get an "E Tick".
Are there any capacitors or filter on the mains entry?

Good luck,

cheerio, mike