Anyone recognize this capacitor type? (fixing Sansui au-707)

[Thomas]

In one of Japanese expert site who is good in repairing vintage audio
equipment, (see link below), he has mentioned use of a higher price BP to
replace old capacitor? Does anyone know what does this BP means?

(See photo C-5C and C-5D, where he is using 1 BP to replace 2 old
capacitors)
http://amp55.com/sansui/607-707/au-707.htm

This model is selling as Sansui AU-717 in the US.

Thanks

Thomas

[Browntimdc]

"Thomas" > wrote in news:bfhdpk
:

> In one of Japanese expert site who is good in repairing vintage audio
> equipment, (see link below), he has mentioned use of a higher price BP
to
> replace old capacitor? Does anyone know what does this BP means?
>

BP means bipolar. Here in the US we call them non-polar or NP capacitors.
They can take DC either way, as opposed to conventional (polar)
electrolytic capacitors that have positive and negative leads.

Note that those caps in photo 5C are pairs of regular electrolytics
placed in series, back to back, positive to positive.

In photo 5D each pair of regular caps is replaced with one non-polar cap.
The non polar cap should have half of the capacity of each of the caps it
replaces. So a pair of 10uF caps would be replaced by one 5uF non-polar.

Non-polar caps are not necessarily expensive. They are used in speaker
crossovers.

http://dkc3.digikey.com/pdf/T032/0655.pdf

http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=72

Tim

[Trevor]

"Browntimdc" > wrote in message
...
> The non polar cap should have half of the capacity of each of the caps it
> replaces. So a pair of 10uF caps would be replaced by one 5uF non-polar.

For coupling caps it is often better to increase the value when size is not
a problem. It would be rare indeed that an increase from 5uF to 10 uF would
have any detrimental effect. The only difference should be a reduction of
the bass roll off frequency.
OTOH the voltage must be adequate and *may* need to be twice the individual
rating of the original caps.

Trevor.

[Mark D. Zacharias]

Nonsense.


Mark Z.


> > The non polar cap should have half of the capacity of each of the caps
it
> > replaces. So a pair of 10uF caps would be replaced by one 5uF non-polar.
>



"Trevor" <trevor@home> wrote in message
u...
>
> "Browntimdc" > wrote in message
> ...
> > The non polar cap should have half of the capacity of each of the caps
it
> > replaces. So a pair of 10uF caps would be replaced by one 5uF non-polar.
>
> For coupling caps it is often better to increase the value when size is
not
> a problem. It would be rare indeed that an increase from 5uF to 10 uF
would
> have any detrimental effect. The only difference should be a reduction of
> the bass roll off frequency.
> OTOH the voltage must be adequate and *may* need to be twice the
individual
> rating of the original caps.
>
> Trevor.
>
>
>
>

[Rocky]

It would be nice to say why it's nonsense for the education of readers here.
A nicer way to say it would be:

Two series equal value electrolytic capacitors do not necessarily act like a
single nonpolar cap of 1/2 the value. The reverse biased electrolytic may
act somewhat like a short circuit, thus the series combination may act a
like a single capacitor of the value of either. Thus if you replace them
with a single nonpolar cap it should be the same value as one of the polar
caps.

Rocky


"Mark D. Zacharias" > wrote in message
thlink.net...
> Nonsense.
>
>
> Mark Z.
>
>
> > > The non polar cap should have half of the capacity of each of the caps
> it
> > > replaces. So a pair of 10uF caps would be replaced by one 5uF
non-polar.
> >
>
>
>
> "Trevor" <trevor@home> wrote in message
> u...
> >
> > "Browntimdc" > wrote in message
> > ...
> > > The non polar cap should have half of the capacity of each of the caps
> it
> > > replaces. So a pair of 10uF caps would be replaced by one 5uF
non-polar.
> >
> > For coupling caps it is often better to increase the value when size is
> not
> > a problem. It would be rare indeed that an increase from 5uF to 10 uF
> would
> > have any detrimental effect. The only difference should be a reduction
of
> > the bass roll off frequency.
> > OTOH the voltage must be adequate and *may* need to be twice the
> individual
> > rating of the original caps.
> >
> > Trevor.
> >
> >
> >
> >
>
>

[browntimdc]

"Rocky" > wrote in
:

> Two series equal value electrolytic capacitors do not necessarily
act
> like a single nonpolar cap of 1/2 the value. The reverse biased
> electrolytic may act somewhat like a short circuit, thus the series
> combination may act a like a single capacitor of the value of
either.
> Thus if you replace them with a single nonpolar cap it should be the
> same value as one of the polar caps.
>

Have you actually made a measurement to see if this is true? Signals
would get grossly distorted if electrolytic caps worked this way.

Tim

[Robert Rowton]

Here's the formula:

CT = 1 / ( ( 1 / C1) + (1 / C2) )

Where CT = total capacitance

[Trevor]

"browntimdc" > wrote in message
...

> Two 10uF in series = 5uF, regardless of the application.

Yes and ET = E1+E2

>Whether to
> put something bigger in is a seperate issue.

Hell, I was *quite* specific, the increase in capacitance will probably not
matter, the voltage will. Measure the DC applied and act accordingly.

If you can't think for yourself, just use half the capacitance and twice the
voltage. This assumes the manufacturer is some kind of god though,
personally I'd rather calculate the capacitive reactance and the max DC
applied for myself.

Trevor.

[Browntimdc]

browntimdc > wrote in
:

> "Trevor" <trevor@home> wrote in
> :
>
>>
>> "browntimdc" > wrote in message
>> ...
>>
>>> Two 10uF in series = 5uF, regardless of the application.
>>
>> Yes and ET = E1+E2
>>
>>>Whether to
>>> put something bigger in is a seperate issue.
>>
>> Hell, I was *quite* specific, the increase in capacitance will
>> probably not matter, the voltage will.
>
> The above statement is self contradictory. Saying 'probably' is NOT
> specific.
>
>> Measure the DC applied and act
>> accordingly.
>>
>> If you can't think for yourself, just use half the capacitance and
>> twice the voltage.
>
> I never said anything about cap voltage rating, so why are you arguing
> with me about it?
>
> And, yes, I can think for myself. And I think you're either a ****ing
> troll or your reading comprehension is **** poor.
>
> Tim
>

OK, sorry, that was harsh Trevor. It's been a rough day already.

Tim