Certainly. Ripple current causes heat.
What can you do about it?
Add bigger capacitors? Yes. That distributes the capacitor heat better, but it also increases the heating in the transformer. Electronic design is almost always a series of compromises.

 

Certainly. Ripple current causes heat.
What can you do about it?
Add bigger capacitors? Yes. That distributes the capacitor heat better, but it also increases the heating in the transformer. Electronic design is almost always a series of compromises.

Minimize equivalent series resistance. Sometimes several smaller caps in parallel have less resistance (and heating). Also, shorter squat caps tend to have lower ESR than taller skinny if not specified.

 

Minimize equivalent series resistance. Sometimes several smaller caps in parallel have less resistance (and heating). Also, shorter squat caps tend to have lower ESR than taller skinny if not specified.

I was thinking that and typing the other.

 

Thanks @#12 and @GopherT for your very valuable advice... it comes in handy for a current project of mine.

 

Minimize equivalent series resistance. Sometimes several smaller caps in parallel have less resistance (and heating). Also, shorter squat caps tend to have lower ESR than taller skinny if not specified.

Now that you mention it... is that why it's not recommended to place electrolytics and/or tantalums in series? because that would increase the overall ESR?

 

Now that you mention it... is that why it's not recommended to place electrolytics and/or tantalums in series? because that would increase the overall ESR?

Also...You will waste a noticeable amount of current in the resistors required to be sure they share the voltage equally.

 

Now that you mention it... is that why it's not recommended to place electrolytics and/or tantalums in series? because that would increase the overall ESR?

Putting two caps of the same value in series cuts capacitance in half. No reason to do that unless you are making an unpolarized cap from a polarized cap.

 

Putting two caps of the same value in series cuts capacitance in half. No reason to do that unless you are making an unpolarized cap from a polarized cap.

There is an antique reason...Some vacuum tube amplifiers had to use 2 caps in series for the B+ because you couldn't buy a high enough voltage capacitor back then. Recently we have seen several people trying to use stacks of, "supercaps" as if they are some kind of substitute for batteries.

 

There is an antique reason...Some vacuum tube amplifiers had to use 2 caps in series for the B+ because you couldn't buy a high enough voltage capacitor back then. Recently we have seen several people trying to use stacks of, "supercaps" as if they are some kind of substitute for batteries.

I've done that in the past, for both reasons quoted... but I've never experimented with supercaps... can't foresee a practical application for them either, at least in my line of work.

 

In the Motive Power world and transit systems, supercaps are all the rage right now. They are putting them in parallel (as a stand-alone battery) with standard lead-acid battery systems because they react faster and recharge quicker in high demand load-dump situations. As far as I know, they are quite successful so far.

 

View attachment 84936

Bottom right: "not for production test"

a) What does it actually mean?
b) If not so, for what then?