High-temperature cap replacement

[Clifford Heath]

The control chip in our oven has gone haywire, and I suspect
the supply filter cap, a 220uF 25VW electro with a 125C temp
rating. It's in a hot place! It filters the supply generated
through two wirewound resisters dropping from 240V.

Is there a better replacement cap I can get for this purpose?
Do tantalum caps withstand this temp better?

Otherwise where might I find (in Melb) a 125C rated cap without
having to pay $10 in postage from Farnell etc? It doesn't seem
to be the kind of thing stocked by the usual suspects.

Clifford Heath.

 

[David L. Jones]

"Clifford Heath" <no@spam.please.net> wrote in message
news:49b46724$0$19982$afc38c87@news.optusnet.com.au...

The control chip in our oven has gone haywire, and I suspect
the supply filter cap, a 220uF 25VW electro with a 125C temp
rating. It's in a hot place! It filters the supply generated
through two wirewound resisters dropping from 240V.

Is there a better replacement cap I can get for this purpose?
Do tantalum caps withstand this temp better?

Otherwise where might I find (in Melb) a 125C rated cap without
having to pay $10 in postage from Farnell etc? It doesn't seem
to be the kind of thing stocked by the usual suspects.

Clifford Heath.

Rockby have some 125 deg rated electros:
http://www.rockby.com.au/searchres.cfm?searchkey=125+deg&imageField.x=0&imageField.y=0

No exact match, but a couple of the 68uF 40V axial jobs might do the trick
if they fit.

Rockby are in Clayton.

Dave.

 

[Eeyore]

Clifford Heath wrote:

The control chip in our oven has gone haywire, and I suspect
the supply filter cap, a 220uF 25VW electro with a 125C temp
rating. It's in a hot place! It filters the supply generated
through two wirewound resisters dropping from 240V.

Is there a better replacement cap I can get for this purpose?
Do tantalum caps withstand this temp better?

Otherwise where might I find (in Melb) a 125C rated cap without
having to pay $10 in postage from Farnell etc? It doesn't seem
to be the kind of thing stocked by the usual suspects.

Not likely either sadly. 105C is good enough for most apps.

Graham

 

[Clifford Heath]

David L. Jones wrote:

Rockby have some 125 deg rated electros

Perfect, David! Thanks for the pointer.

Still interested if anyone can answer whether other types might suit.

 

[Franc Zabkar]

On Mon, 09 Mar 2009 11:43:53 +1100, Clifford Heath
<no@spam.please.net> put finger to keyboard and composed:

The control chip in our oven has gone haywire, and I suspect
the supply filter cap, a 220uF 25VW electro with a 125C temp
rating. It's in a hot place! It filters the supply generated
through two wirewound resisters dropping from 240V.

Is there a better replacement cap I can get for this purpose?
Do tantalum caps withstand this temp better?

Otherwise where might I find (in Melb) a 125C rated cap without
having to pay $10 in postage from Farnell etc? It doesn't seem
to be the kind of thing stocked by the usual suspects.

Clifford Heath.

Look for a capacitor with a solid dielectric.

This series is targeted at industrial high temperature, automotive,
military and space applications:
http://www.vishay.com/docs/28355/28355.pdf

• Extremely long useful life: 20 000 hours at 125 °C
• Extended high temperature range up to 200 °C
• Excellent low temperature impedance and ESR behaviour
• Charge and discharge proof, application with
0 ohm resistance allowed

Here are Vishay's Australian distributors/agents/sales offices:
http://www.vishay.com/capacitors/list/product-28354/sales?locs=Australia

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Clifford Heath]

Thanks all, the oven is working perfectly. Rockby had the
exact part (220uF 25V 125degC), and they were less than a
kilometre detour for my son this morning. WIN!

Clifford Heath.