Electrolytic Capacitors

aq1261101415

Electrolytic Capacitors [Copy link]

If you connect a 100uf and 1000uf electrolytic capacitor in parallel and connect the positive and negative poles of the power supply in reverse, which capacitor will explode first? Or will they explode at the same time?

maychang

What's going on? Thinking about destroying a wave of electrolytic capacitors? Also asking "which capacitor will explode first"?

1399866558

Looking forward to the test results from experts.

aq1261101415

maychang posted on 2019-6-24 19:52 What's going on? Thinking about destroying a wave of electrolytic capacitors? Also asking "which capacitor explodes first"?

I didn't mean to destroy all the electrolytic capacitors, because I accidentally connected them the wrong way today, and the big capacitor exploded. Fortunately, I was fast and the small electrolytic capacitor was fine, but I can't figure out why the big electrolytic capacitor exploded first.

maychang

aq1261101415 posted on 2019-6-24 20:15 I didn’t mean to destroy a wave of electrolytic capacitors, because I accidentally connected them the wrong way today, and the large capacitor exploded. Fortunately, I was fast and the small electrolytic capacitor was fine...

The explosion of electrolytic capacitors is mainly due to the heat causing the liquid electrolyte in the shell to boil and the pressure inside the shell to increase.

The large electrolytic capacitor was short-circuited first (the oxide film on the aluminum foil dissolved quickly after reverse connection, roughly equivalent to a short circuit), and the current was quite large, causing the power supply output voltage to drop. The small electrolytic capacitor may be a high-voltage electrolytic capacitor, and the oxide film on the aluminum foil was thicker and had not yet completely dissolved, and the power supply was turned off. The small electrolytic capacitor was only damaged, but not short-circuited or exploded.

qwqwqw2088

How much pressure exceeds the withstand value and causes explosion?

Electrolysis has explosion-proof valve, cross cut

chunyang

There is no definite answer to this question. Which one explodes first depends on the capacitor's withstand voltage, materials, manufacturing process, etc. Only when other conditions are equal will large-capacity electrolytic capacitors explode first. Aluminum electrolytic capacitors with too small a capacity are unlikely to explode because they contain very little liquid, unless the reverse pressure is high enough, but it is hard to say for tantalum electrolytic capacitors.