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High power non-polarised capacitors?

17 Jul 10 - 09:08 AM (#2946681)
Subject: High power non-polarised capacitors?
From: Richard Bridge

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?


17 Jul 10 - 09:28 AM (#2946694)
Subject: RE: High power non-polarised capacitors?
From: Rog Peek

Try Rapid
Rog


17 Jul 10 - 10:17 AM (#2946721)
Subject: RE: High power non-polarised capacitors?
From: Rog Peek

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

Rog


17 Jul 10 - 11:24 AM (#2946753)
Subject: RE: High power non-polarised capacitors?
From: Richard Bridge

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.


17 Jul 10 - 11:58 AM (#2946758)
Subject: RE: High power non-polarised capacitors?
From: Paul Burke

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


17 Jul 10 - 12:47 PM (#2946784)
Subject: RE: High power non-polarised capacitors?
From: Kampervan

Any reason why Wharfedale can't supply?

Intrigued K/van


17 Jul 10 - 02:00 PM (#2946800)
Subject: RE: High power non-polarised capacitors?
From: GUEST,Girl Friday

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


17 Jul 10 - 03:06 PM (#2946823)
Subject: RE: High power non-polarised capacitors?
From: Richard Bridge

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!


17 Jul 10 - 03:41 PM (#2946839)
Subject: RE: High power non-polarised capacitors?
From: JohnInKansas

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


17 Jul 10 - 03:59 PM (#2946849)
Subject: RE: High power non-polarised capacitors?
From: Richard Bridge

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.