Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

I would personally replace all of them as a kit especially if they are being
used as timing or wave shaping. The higher capacitance rating when being
used as a filter is going to remove more ripple.

"Art Deco" wrote in message
...
Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

If I were doing it I would replace all as a set especially if they are being
used as wave shaping or timing caps. As a DC filter any capacitance
increase will usually remove more riple.

"Art Deco" wrote in message
...
Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

Art Deco wrote:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In any combination you like.


In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

It's just a *maximum* voltage.

Graham

On Thu, 19 Oct 2006 14:53:37 +0100, Eeyore
wrote:



Art Deco wrote:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In any combination you like.

OK, thanks.

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

It's just a *maximum* voltage.

So in the third example above, where a 330uF 16V cap is replaced with
a 470uF, 35V cap, it wouldn't be advisable to exceed 35V for the
replacement?

if there are switching supplies involved make the replacements are
rated for switching service or low/very low ESR

If I were doing it I would replace all as a set especially if they are being
used as wave shaping or timing caps. As a DC filter any capacitance
increase will usually remove more riple.

"Art Deco" wrote in message
...
Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

Art Deco wrote:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

These largish value caps are usually used for smoothing and decoupling,
where values a bit bigger are a non issue. The voltage rating is the
max V the cap is rated to work with, so again replacing with the next
voltage up is a non issue.


NT

Art Deco wrote:

On Thu, 19 Oct 2006 14:53:37 +0100, Eeyore
wrote:
Art Deco wrote:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In any combination you like.

OK, thanks.

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

It's just a *maximum* voltage.

So in the third example above, where a 330uF 16V cap is replaced with
a 470uF, 35V cap, it wouldn't be advisable to exceed 35V for the
replacement?

It's not going to exceed 35V is it ? The voltage must be under 16V or the
original cap wouldn't have been suitable.

Graham

Meat Plow wrote:

On Thu, 19 Oct 2006 13:50:51 +0100, Art Deco Has Frothed:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver using a
kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the original
capacitor values and the upgraded replacements provided, for instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a set
or can any one of them be replaced with the upgraded value?

Either or.

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

I always opt for a higher max voltage if available. The capacitive value
depends on what the cap does. Electrolytics usually can be subbed by
higher values maybe 20% higher without side effects.

Why do you have this idea about 20% ?

Any voltage higher than that required is just fine, although it would be silly
to take it to extremes.

Graham

"Meat Plow" wrote in message
news
On Thu, 19 Oct 2006 13:50:51 +0100, Art Deco Has Frothed:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver using a
kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the original
capacitor values and the upgraded replacements provided, for instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a set
or can any one of them be replaced with the upgraded value?

Either or.

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

I always opt for a higher max voltage if available. The capacitive value
depends on what the cap does. Electrolytics usually can be subbed by
higher values maybe 20% higher without side effects.



They are a bit better these days, but the capacitance value tolerance on
electrolytics used to be +80% / -20%. An increased voltage rating, within
reason, is of little consequece, provided the part is still of a suitable
physical size to fit where it has got to go. Going up too far on the
voltage, can alter other characteristics of the cap, such as its ESR, which
may or may not be a problem, depending on the cap's function. For caps used
as filters in switch mode or linear power supplies, an increase in value is
often beneficial to the filtering function, but if you go too far, then the
initial charging current from cold, may prove too much for some prior
component, such as a diode or regulator transistor. As Meaty-boy says, going
up 20% on the nominal value will not present a problem, and the values
supplied in the kit should be just fine.

Arfa

On Fri, 20 Oct 2006 00:56:49 +0100, Eeyore
wrote:



Art Deco wrote:

On Thu, 19 Oct 2006 14:53:37 +0100, Eeyore
wrote:
Art Deco wrote:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In any combination you like.

OK, thanks.

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

It's just a *maximum* voltage.

So in the third example above, where a 330uF 16V cap is replaced with
a 470uF, 35V cap, it wouldn't be advisable to exceed 35V for the
replacement?

It's not going to exceed 35V is it ? The voltage must be under 16V or the
original cap wouldn't have been suitable.

I meant the voltage rating of the replacement capacitor.
Would it make a difference here if a 470uF 50V capacitor was used?

On 19 Oct 2006 12:44:34 -0700, wrote:

Art Deco wrote:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

These largish value caps are usually used for smoothing and decoupling,
where values a bit bigger are a non issue. The voltage rating is the
max V the cap is rated to work with, so again replacing with the next
voltage up is a non issue.

Thanks, everyone. I now have a better idea how this all works.

"Art Deco" wrote in message
...
On Fri, 20 Oct 2006 00:56:49 +0100, Eeyore
wrote:



Art Deco wrote:

On Thu, 19 Oct 2006 14:53:37 +0100, Eeyore
wrote:
Art Deco wrote:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In any combination you like.

OK, thanks.

In the latter case, a follow-up quesion would be how much variation
in
capacitor value is permissible (presumably as long as it's higher)?

It's just a *maximum* voltage.

So in the third example above, where a 330uF 16V cap is replaced with
a 470uF, 35V cap, it wouldn't be advisable to exceed 35V for the
replacement?

It's not going to exceed 35V is it ? The voltage must be under 16V or the
original cap wouldn't have been suitable.

I meant the voltage rating of the replacement capacitor.
Would it make a difference here if a 470uF 50V capacitor was used?

Almost certainly not, provided it fitted the board ok. But note that if it's
much bigger than the original part, that might bring it closer to some item
that runs hot, and this will shorten the life of the replacement by a
considerable factor...

Arfa

In power supplies the capacitance values are usually not critical, so
anything up to 3 times the value is probably okay, actually, a good
thing.

The voltage rating can also be higher, up to 3 times higher is
perfectly okay. If you go above that, there's a chance the capacitor
will over time lose part of it's dielectric thickness, which will
increase the capacitance, which is harmless in 98% of the cases.

On Fri, 20 Oct 2006 06:20:26 +0100, Art Deco put
finger to keyboard and composed:

On Fri, 20 Oct 2006 00:56:49 +0100, Eeyore
wrote:



Art Deco wrote:

On Thu, 19 Oct 2006 14:53:37 +0100, Eeyore
wrote:
Art Deco wrote:

Hi everyone,

I've been upgrading a simple power supply in a satellite receiver
using a kit provided by a company selling spares.

I've noticed that there's quite a bit of difference between the
original capacitor values and the upgraded replacements provided, for
instance

Old New

47uF, 35V 100uF, 35V
2200uF, 10V 2200uF, 16V
330uF, 16V 470uF, 35

etc

My querstion is: do the upgraded capacitors only work together as a
set or can any one of them be replaced with the upgraded value?

In any combination you like.

OK, thanks.

In the latter case, a follow-up quesion would be how much variation in
capacitor value is permissible (presumably as long as it's higher)?

It's just a *maximum* voltage.

So in the third example above, where a 330uF 16V cap is replaced with
a 470uF, 35V cap, it wouldn't be advisable to exceed 35V for the
replacement?

It's not going to exceed 35V is it ? The voltage must be under 16V or the
original cap wouldn't have been suitable.

I meant the voltage rating of the replacement capacitor.
Would it make a difference here if a 470uF 50V capacitor was used?

The only things I would be concerned about would be whether the higher
voltage types had higher leakage, which *may* effect some timing
applications, or whether the higher voltage types had higher ESR
values, which would result in poorer performance in switchmode supply
applications (as stated elsewhere in this thread).

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