Question on voltage of electrolytic cap
 

Would it hurt anything to replace an alectrolytic cap (high temp, if that
matters) with one of the same value (220uF) but a higher voltage rating?
Seems like it wouldn't, but I thought I'd ask...

Thanks,

D

Question on voltage of electrolytic cap
 

In article merica,
Dave wrote:
Would it hurt anything to replace an alectrolytic cap (high temp, if
that matters) with one of the same value (220uF) but a higher voltage
rating? Seems like it wouldn't, but I thought I'd ask...

No - if there's space for it. They're bigger, like for like.

--
*Reality? Is that where the pizza delivery guy comes from?

Dave Plowman London SW
To e-mail, change noise into sound.

Question on voltage of electrolytic cap
 

"Dave Plowman (News)" wrote in message
...
In article merica,
Dave wrote:
Would it hurt anything to replace an alectrolytic cap (high temp, if
that matters) with one of the same value (220uF) but a higher voltage
rating? Seems like it wouldn't, but I thought I'd ask...

No - if there's space for it. They're bigger, like for like.

--
*Reality? Is that where the pizza delivery guy comes from?

Dave Plowman London SW
To e-mail, change noise into sound.

Thank you, Dave. :)

Yeah, the 50V is more than twice the size of the 35V, and may not fit. But
it's all I seem to be able to find for that value and high temp.

'preciate it.

Dave

Question on voltage of electrolytic cap
 

"Dave" wrote in
netamerica:

Would it hurt anything to replace an alectrolytic cap (high temp, if
that matters) with one of the same value (220uF) but a higher voltage
rating? Seems like it wouldn't, but I thought I'd ask...

Thanks,

D




nothing,if the physical size of the new cap fits in the space of the old
cap.
Mind your ESR requirements.
Switcher power supplies need low-ESR caps.

--
Jim Yanik
jyanik
at
kua.net

Question on voltage of electrolytic cap
 

In theory, if the cap has a voltage rating much higher than the actual
circuit voltage (say, a 100V cap in a 50V DC circuit), the capacitor is more
likely to deform.

That's the theory. I've never seen any systematic study of it. Anyone know
"fer shure"?

Question on voltage of electrolytic cap
 

"Jim Yanik" wrote in message
...
"Dave" wrote in
netamerica:

Would it hurt anything to replace an alectrolytic cap (high temp, if
that matters) with one of the same value (220uF) but a higher voltage
rating? Seems like it wouldn't, but I thought I'd ask...

Thanks,

D




nothing,if the physical size of the new cap fits in the space of the old
cap.
Mind your ESR requirements.
Switcher power supplies need low-ESR caps.

--
Jim Yanik
jyanik
at
kua.net

Thank you, Jim. Any ideas on how I can determine what the ESR of a cap is?
Seriously, I know this matters, but have no idea as to how to apply the
question. Maybe Google... Just a thought.

'preciate it.

dave

Question on voltage of electrolytic cap
 

"Dave" wrote in
:


"Jim Yanik" wrote in message
...
"Dave" wrote in
netamerica:

Would it hurt anything to replace an alectrolytic cap (high temp, if
that matters) with one of the same value (220uF) but a higher
voltage rating? Seems like it wouldn't, but I thought I'd ask...

Thanks,

D




nothing,if the physical size of the new cap fits in the space of the
old cap.
Mind your ESR requirements.
Switcher power supplies need low-ESR caps.

--
Jim Yanik
jyanik
at
kua.net

Thank you, Jim. Any ideas on how I can determine what the ESR of a
cap is? Seriously, I know this matters, but have no idea as to how to
apply the question. Maybe Google... Just a thought.

'preciate it.

dave



Dick Smith Electronics used to sell an inexpensive ESR meter kit(I have
one,love it),Anatek may still carry them. around $50 USD.

you could probably look up the manufacturer's specs on their website.

--
Jim Yanik
jyanik
at
kua.net

Question on voltage of electrolytic cap
 

"Jim Yanik" wrote in message
...
"Dave" wrote in
:


"Jim Yanik" wrote in message
...
"Dave" wrote in
netamerica:

Would it hurt anything to replace an alectrolytic cap (high temp, if
that matters) with one of the same value (220uF) but a higher
voltage rating? Seems like it wouldn't, but I thought I'd ask...

Thanks,

D




nothing,if the physical size of the new cap fits in the space of the
old cap.
Mind your ESR requirements.
Switcher power supplies need low-ESR caps.

--
Jim Yanik
jyanik
at
kua.net

Thank you, Jim. Any ideas on how I can determine what the ESR of a
cap is? Seriously, I know this matters, but have no idea as to how to
apply the question. Maybe Google... Just a thought.

'preciate it.

dave



Dick Smith Electronics used to sell an inexpensive ESR meter kit(I have
one,love it),Anatek may still carry them. around $50 USD.

you could probably look up the manufacturer's specs on their website.

--
Jim Yanik
jyanik
at
kua.net

Why, *thank you*. Will check out said kit, and Anatek as well. Much
appreciated.

Dave

Question on voltage of electrolytic cap
 

"William Sommerwerck" wrote in message
. ..
In theory, if the cap has a voltage rating much higher than the actual
circuit voltage (say, a 100V cap in a 50V DC circuit), the capacitor is
more
likely to deform.

That's the theory. I've never seen any systematic study of it. Anyone know
"fer shure"?


Yes, the 100 volt electrolytic will eventually become a 50 volt electrolytic
(or whatever voltage is actually impressed on it). The aluminum oxide film
that is the actual dielectric of the capacitor will hydrolyze eventually
dissolving the oxide back into the electrolyte. This is why relatively new
electrolytic capacitors sometimes need to be reformed. In most cases, this
is seen as an elevated leakage current in the first few hours of operation.
In the old days when vacuum tube rectifiers were in vogue, power supply
electrolytics would be subjected to a higher voltage than their normal
operating voltage until all the tubes were "warmed up". This is why high
voltage electrolytics often had a surge voltage rating high enough to
prevent breakdown during those few seconds that the supply was not providing
current.

I wrote a number of posts about 9 to 10 years ago on electrolytic capacitors
and their chemistry. Most of these can be found archived at
http://yarchive.net/electr/electrolytic_caps.html.

Dr. Barry L. Ornitz WA4VZQ