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Just another capacitor :whistle:

ryansoh3

ryansoh3

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Hey guys,

I picked up a cap in a local electronics shopping complex,
and it's slightly big. :whistle:

The seller told me that it was new, but it was quite dusty.
ssc5851.jpg


Here it is!
ssc5852.jpg


Next to a Red Bull can:
ssc5853.jpg


It's rated at 10V 680,000uF, and I plan to charge it using my CPU power supply.

Any advice on exactly how I should charge it?

Cheers! :beer:
 





jeffreythe00

jeffreythe00

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You can use the 12V rail. Just make sure you don't overcharge it past the 10V rating. You will also need a high wattage resistor. I used a coffee maker with my super caps xD
 
ryansoh3

ryansoh3

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jeffreythe00 said:
You can use the 12V rail. Just make sure you don't overcharge it past the 10V rating. You will also need a high wattage resistor. I used a coffee maker with my super caps xD
Click to expand...

Yup, thanks for the advice. Around what ohms should the resistor be?

The only high wattage resistor (10W) I have is 1 Ohm in my test load.

Wow, a coffee maker--awesome! Did you hook it up to an inverter?

Cheers! :beer:
 
jeffreythe00

jeffreythe00

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Your 1 ohm 10W resistor will not work. At 12V your cap will be pulling 12A and your resistor will be putting out 110W of heat. So you would need a higher wattage resistor or one with more ohms
I'd suggest using a heating element like I did. Its more likely you have one around
A coffee machine would work too
You would need to run 12V through the coffee machine. You would probably be pulling an amp or so off the psu as well.

Btw. The coffee machine needs to be unplugged :p
 
grainde

grainde

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Hook it up to a car battery! :crackup: What are you planning to do with it? :beer:
 
ryansoh3

ryansoh3

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grainde said:
Hook it up to a car battery! :crackup: What are you planning to do with it? :beer:
Click to expand...

Hahaha, I found an old 9 volt wall wart and connected it to the cap.

It charges in about 5 sec because it's only 0.68F.

I guess just make some cool sparks!

Cheers! :beer:
 
ZRaffleticket

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Good lord man. What are you trying to blow up? I thought one an eighth the size of that was menacing...
 
TheDukeAnumber1

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I can honestly say high power capacitors scare me more than high power lasers, but because of that they are very cool. Charge it up and try to turn the energy into an EMP blast. Stay safe don't vaporize your hand.
 
jeffreythe00

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^ 10v is not dangerous at all. If it was... well you would have to be REALLY careful with a car battery :whistle:

To get hurt from a 10V capacitor. You'd have to be doing something REALLY stupid. Like sitting in a super concentrated bath of salt water or something.

The worst danger that cap poses is a possible burn from melted crap.
 
TheDukeAnumber1

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65mA through the heart can kill. I know it's really unlikely though, I've always associated a high capacity with danger but then again I've never owned a huge capacitor.
 
T

Things

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TheDukeAnumber1 said:
6mA through the heart can kill.
Click to expand...

But there is no way 10V will even pierce the skin, let alone make it to your heart. You'd have to stick the cap across your heart, literally, before it'll do anything.
 
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Hiemal

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It's definitely a great DC filtering cap... Be decent for a low voltage power supply, or maybe an amplifier!

I have some pretty chunky caps too, 2200 uF at 350 VDC. Those will kill you. xD

Capacitors are awesome, but you do need to respect the higher voltage ones. I think around 35 volts and up is where I'd start to handle it more carefully.
 
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F

flare09

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I have a few 5v 1F caps. I charge those up and two run an led for...30ish minutes straight, its literally crudely soldered to the caps so, its charge and on. But they are about a silver dollar sized around and a quarter inch thick
 
Seoul_lasers

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Le Quack said:
It's definitely a great DC filtering cap... Be decent for a low voltage power supply, or maybe an amplifier!

I have some pretty chunky caps too, 2200 uF at 350 VDC. Those will kill you. xD

Capacitors are awesome, but you do need to respect the higher voltage ones. I think around 35 volts and up is where I'd start to handle it more carefully.
Click to expand...

Actually, that would make a great analog (tube amp) filter cap.. nice find! Probably overkill for filtering for HIFI too.
 
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Cyparagon

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jeffreythe00 said:
Your 1 ohm 10W resistor will not work. At 12V your cap will be pulling 12A and your resistor will be putting out 110W of heat.
Click to expand...

P=I^2*R. 144 watts initially.

A farad is an amp second per volt. So at 0.68F and 12A, the cap will be charged to 10V in a half a second. A 10W resistor can probably handle the average power for half a second.

This isn't constant current though, so you need the RC time constant which is 0.68. The formula for cap voltage with respect to time would then be 12*(1-1/e^(t/0.68)) so it charges to 10V in 1.2 seconds and dissipates... meh, fuggit. Too late at night for calculus.

The point is it charges too fast for you to keep an eye on the voltage. The power supply and the resistor can probably handle it, but you run the risk of charging it to 11 or 12V by accident.
 
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