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Electrolytic capacitor

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Electrolytic capacitor | 3 May, 2014

What are the possible reasons for electrolyte leakage What is the purpose of the vent in the capacitor? Why vent is not being maintained for all types / values of the capacitors? What is the significance of the end seal configuration. Why end seal configurations are different for different manufacturers? If vent not there for any electrolytic capacitor, then is there any chance of getting the electrolytic leakage / blasting the capacitor through the end seal?

Pls share your opinions on the above queries as we are facing so many field problems in power supply circuits due to the above reasons?

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Electrolytic capacitor | 5 May, 2014

The vent is there for reasons as the name implies. It's a safety feature to prevent the cap from exploding if over-tasked. Yes, without the relief on the end, the caps have a potential to become missiles when they go. I had one go off when my hand was over it. If you ever had a fire cracker go off in your hand, the feeling is quite similar.

For reasons for the leakage, I would look at your design, primarily the layout of your pcb. If you are experiencing per-mature failures on your electrolytic caps, this may be do to high operating temps on your power supply. Are the caps in close proximity to heat sinks? High temps will dry out the electrolyte in the caps preventing the caps from holding a charge, thereby preventing a lot of ripple.

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