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Electrolytic Capacitors

Cam453

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So say I was building a bridge rectifier for 12v AC and decided to put an electrolytic filtering cap to reduce ripples. Let's also say it's rated for 50v.

Now theoretically if it blew up for what reason would it have done that? :whistle:
 





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Sep 20, 2008
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You need to measure the AC voltage to the Bridge
first. Then you can estimate the DC output. It will
be slightly higher that the AC voltage.
Then double that to choose what rated Voltage Cap
that you need.

BTW... a sure way of blowing up an Electrolytic cap is
to apply a reverse voltage...:eek:


Jerry
 
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With a full wave rectifier, the output will be Vac*√2-1.4. If it was 12VAC, you should expect 15.5VDC. Even 24VAC shouldn't be enough to pop a 50V cap.
 
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From what I can remember, the BEST way to blow up just about any capacitors is to leave them in the hands of high-school electronics students unsupervised with bench top power supplies.
And I also remember that besides the loud bangs that they always smell rather bad enough that the smell stays in your nose for a few hours afterwards.
They can leave an interesting spackle pattern on the back of a heavy duty denim jacket too. Ooooooooo. Molten metal spackle on the jacket...that's cool.
:crackup:
 

Cam453

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It was hooked up in reverse I messed up what the longer pin meant XD and it's molten metal? It seemed more like threads of paper.
 
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Yeah. In your case with that type of capacitor.

But if you use a great big canister of a capacitor and hook it across the PSU cranked to max and let `er go until failure...
Mind you. It wasn't me that was doing this. I had my back to the guy the whole time. My "lab" partner was watching it over my shoulder throughout and by watching his face, and by listening, I could tell what was going on.
The best part was when it blew up and I didn't even flinch. My partner was freaking out. He was all "You didn't even move !!! No Way ! I can't believe you man ! You just let it explode behind you and you don't even care ?! Blah Blah blah."
Hell it was worth it to have this guy going on for days about it ! I knew enough about the physics involved and the way my jacket protected my skin from hot metal. All I had to worry about was my hair, and back in the late 70's early 80's the hair length was rather long and thick so that wouldn't be much of an issue either.
It was fun having people asking how I got the metal "splashes" on my jacket for the next couple of weeks. But it eventually peeled off.
I wouldn't recommend doing it though. It is actually a rather loud bang and I'm not lieing about the smell getting stuck in your nose for some time. Somewhat nauseating after a couple of hours to me.

Glad you figured out where you went wrong.
 
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Mind you. It wasn't me that was doing this. I had my back to the guy the whole time. My "lab" partner was watching it over my shoulder throughout and by watching his face, and by listening, I could tell what was going on.

Yeah... Yeah.... Yeah....
"Hey Doc, my friend has this rash on his......":crackup::crackup::crackup:

Jerry
 




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