High power non-polarised capacitors?

Subject: RE: High power non-polarised capacitors?
From: Richard Bridge
Date: 17 Jul 10 - 03:59 PM

I give up on Farnell's searach engine - when I search for non-polarised it keeps showing me caps with DC voltage ratings - snaaarl.

Thanks JiK - I'll try that.

Subject: RE: High power non-polarised capacitors?
From: JohnInKansas
Date: 17 Jul 10 - 03:41 PM

If you haven't already tried them, th Thomas Register lists 13 audio capacitor supplers.

I can't tell from the front-page listing whether any of them are suitable for what you want, but you can probably flip through them more knowledgeably than I can.

As you indicated, most of the manufacturers seem to be in China, but there also appears to be a cluster of them in India as well. Maybe the India-ns speak better Anglish(?) and would be better supported.

John

Subject: RE: High power non-polarised capacitors?
From: Richard Bridge
Date: 17 Jul 10 - 03:06 PM

I did search Farnell's site, but found none. I'll try again. There is however a snag - to order bay any of the methods that allow you to buy online there is a hefty minimum order size - I remember it as being well over the total of the last bundle of electrolytics (polarised) that I wanted to buy.

K - Wharfedale is now owned by the chinese and although I have emailed them the normal level of aftersales service from chinese owned companies is negative - sor tof "NO sir why don't you buy a new one rahter than repairing" - or sometimes "yes we have spares but it's cheaper to buy a whole new unit".

Sue - they are not exactly everyday items!

Subject: RE: High power non-polarised capacitors?
From: GUEST,Girl Friday
Date: 17 Jul 10 - 02:00 PM

Len is on the case - he might have some you can have.

Subject: RE: High power non-polarised capacitors?
From: Kampervan
Date: 17 Jul 10 - 12:47 PM

Any reason why Wharfedale can't supply?

Intrigued K/van

Subject: RE: High power non-polarised capacitors?
From: Paul Burke
Date: 17 Jul 10 - 11:58 AM

Farnell carry some. I hope you've got the spec right: a 500V, 200uF job is £60 a knock.

Subject: RE: High power non-polarised capacitors?
From: Richard Bridge
Date: 17 Jul 10 - 11:24 AM

Yep, it has to be non-polarised, it's going in a crossover (and I think it's a first-order Butterworth crossover but I have not had a few minutes to sketch the circuit yet) so it will be subject to total voltage reversal at all frequencies within the audio spectrum. The reason it needs to be 220microFarad is that the crossover frequency is 160 Hz, and the voltage requirement is because the sub runs to 400 watts RMS and about 1000 watt peak. In fact if I could get higher voltage I'd likely go for it since I can see from the marks of previous soldering that this crossover has been fried before, possible twice before.

There used to be some lovely ones made in Japan (although expensive) but the main licensee closed down in 2004 and the licensor in 2007, and there seems to be no new old stock left.

Subject: RE: High power non-polarised capacitors?
From: Rog Peek
Date: 17 Jul 10 - 10:17 AM

Ignore that, all their high voltage non polarised capacitors appear to be very small values. Does it have to be non-polarised?

Rog

Subject: RE: High power non-polarised capacitors?
From: Rog Peek
Date: 17 Jul 10 - 09:28 AM

Try Rapid
Rog

Subject: High power non-polarised capacitors?
From: Richard Bridge
Date: 17 Jul 10 - 09:08 AM

OK, this may be a bit off the wall for this board, but I have spent hours looking for some 220uF 160V (or greater) non-polarised capacitors to fix up a blown crossover in a high-power sub (Wharfedale Twin 15XB, unpowered).

I can't find any anywhere at any price!

Has anyone got any leads?