Electrolytic capacitors.

[Chops54]

I'm interested to know if electrolytic capacitors can survive being subjected to wrong polarity. I have a pair here in a split rail power supply ( 1000uf @ 25V ) that have been run arse about for thirty seconds or so. I can see slight bulging on the top vents. I'm going to replace them anyway but I'd appreciate your thoughts.

 

[Barrymagrec]

Pretty much no. You MIGHT get away with it for a small fraction of a second but not longer. You were very lucky they didn`t explode after 30 seconds.

 

[Mynamemynaim]

I think the bulge says it all...

 

[Vinny]

In one way or another, electrolytic cap's are anodised (oxidised) to produce the dielectric. Reverse the polarity and you de-anodise (reduce) the dielectric, ultimately destroying the dielectric. You end up with a resistor, actually a very low R resistor, fairly quickly. Details depend on design and the metal used as the anode (which is what is anodised).

 

[Arkless Electronics]

/\ This. They are toast.

 

[Chops54]

Thanks all. I’ll order some replacements.