• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Can someone tell me what these capacitors do ??????

Master Yoda

New Member
I have a small Toppower 30 Volt 5-Amp desktop power supply. I have had it for many years now and it gets used vary sparingly!
I took i out of the storage cupboard where I keep it to test some COB LED's. After completing this I noticed something rattling inside of the metal case.
I opened it up and and found 2-metal covers from two electrolytic capacitors laying loose on the base of the unit.
I do not know when this might have happened but they must have blown off or simple came off with expansion occurring inside of the capacitors.
I removed what remained of the 2- Capacitors and replaced them with new one that I had in stock.
I tested the unit and every thing seemed fine, however the unit seemed to be working well before the replacements.
My question to you knowledgeable users is what is the function of these two capacitors.
I have included below 2- images that should help, one of the unit (Blurry) the other showing the location of the capacitors.
Thoughts please.
 

Attachments

MacIntoshCZ

Active Member
Output filtering. What did you expect? Its electrolytic.
 

Diver300

Well-Known Member
Most Helpful Member
It's quite common for circuits to work with capacitors that are significantly degraded. Capacitors are often specified with larger values than needed to allow the system to work when the capacitors have lost some of their capacitance.

Electrolytic capacitors will degrade with time, especially if they are hot, whether they are used or not. Degredation can be loss of capacitance, but it can also be increase in internal resistance.

The output filter capacitors may generate more heat, and fail quickly, if they are not large enough or have too much internal resistance. The degradation during storage could have taken them to the point where they failed very quickly as soon as the power supply was used.
 

MacIntoshCZ

Active Member
Thank you for the reply!
I am barely a novice and have come here to avail myself of those who have knowledge far ahead of my self.
Thank You again!
Those caps are mostly used for filtering, it can be also used for time delay and maybe hardly for decoupling
 

Master Yoda

New Member
I want to thank you all for you time that you spent in responding.
I now have a clearer indication for the functions of the capacitors.
Thank you all again!
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
Output filtering. What did you expect? Its electrolytic.
Well, more like input to the regulator. One the output (end use), they would defeat the axioum "The voltage across a capacitor cannot change instantaneously". You usually see smaller caps on the output.
 

EE World Online Articles

Loading
Top