how do you safely discharge a cap?

[dr.beats 10+ year member]

i'm taking my system out to sell my car. i want to discharge my cap. how do you do it? thanks

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[req 5,000+ posts]

lick the + and the - at the same time.

just kiddin. dont do that. just unplug the fuse in the + wire between the capicator and your car battery, then turn your system on, and let it play for a few seconds. it will drain the cap really quick. then turn the car off - DO NOT REPLACE THE FUSE YET - and unplug the cap, tape off the + wire, and replace your fuse.

cap = drained.

 

[johnecon2001 5,000+ posts]

take a cable and run from the negative to a metal stake (preferably copper) stuck in the ground. let it sit overnight. your done.

 

[B@SSAN8OR 10+ year member]

you could use a light buld also

 

[boister77 10+ year member]

don't know if it's the best way, but when i had a cap i would simply disconnect my battery. i would then open my door and let the interior lights drain the cap. you'll know when the cap is discharged when your lights are no longer lit. you can be safe and check your cap with a dmm.

 

[Zash 10+ year member]

In elecricity my teacher said that connecting the + and - of a capacitor would discharge it...

http://micro.magnet.fsu.edu/electromag/java/capacitor/

 

[pavengmike6 10+ year member]

YES you can touch the + and - but the problem is the stored power HAS TO GO somewhere. And when you are dealing with that much AMPS stored it could KILL you if you do it wrong.

 

[Zash 10+ year member]

You'll be fiiiiiiiiiiiiiiiiiiine

 

[dotorg 10+ year member]

In my younger and stupider days, I'd do it with a big screwdriver... until I discharged a cap that had been sitting for ten years in a 3-phase power conditioner, and it welded the screwdriver to the terminals and the spark knocked me on my ass.

The taking-the-fuse-out method is good if the cap is actually hooked to something //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[rippinitup7 10+ year member]

you can pull your battery cable but still have the wire from cap going to the cars power wire and just open your door like mentioned, the lights will drain it completely and since its not connected to the battery it can't charge back up.

 

[JimJ 5,000+ posts]

never short a cap...unless you have a death wish...

once you'd exploded an electrolytic you won't soon do it again on purpose //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[dr.beats 10+ year member]

well, not going to lick it. don't have any spikes. i actually already had everything out of the car before i asked the question. would it be possible to just hook something of relatively low importance to the +, - and drain it that way? that would be the same as draining it by means of unhooking the fuse from the batterry and running the radio for a minute wouldn't it? just not as big a current draw? ps-thanks for the ideas //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

 

[DBfan187 5,000+ posts]

never short a cap...unless you have a death wish...
once you'd exploded an electrolytic you won't soon do it again on purpose //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Done that a bunch of times. Fun to watch. Screwdrivers as mentioned above, work very well. Or, have you ever played with the cap on a disposible camera? OMFG. Best fun you could ever have. Walk upto someone, touch them on the back of the neck, run away in laughter.//content.invisioncic.com/y282845/emoticons/wacky.gif.cf4a48f9e6dfe9504ffd2c946fd2f340.gif

Just connect the 2 terminals together. VIOLA. Discharged. You don't have to wait overnight. They'll discharge in less than a sec.

 

[swimfreak26 10+ year member]

First, to answer your question....drive down to radio shack and get a high impedence resistor. Connect this to both terminals for a while and it will drain. Another, cheaper way to do this (although the resistor will cost like $1) would be to connect a light bulb to both terminals using wires (neg to neg, pos to pos).

secondly...

In elecricity my teacher said that connecting the + and - of a capacitor would discharge it...

Don't ever do this without a resistor in the way, you will not be very happy with the explosive (quite literally) results.

 

[the_flatlander 10+ year member]

if you connect the + and - terminals together could you please video tape it and post it on here //content.invisioncic.com/y282845/emoticons/popcorn.gif.32dd9e22fd77e77bc3c907062768fcd2.gif//content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif