1984rx7roqet

So I have the power going to the cap, and from the ap it goes to the amp? right? Thn my ground is going from the amp to the cap to the ground. Is this right? If this is right, then why in hell is it creating sparks everytime I try to touch the ground to the grounding point. Do I have something backwords? Thanks guys

KeithC

Sounds like you have it wired correctly..........It will make a big spark when you make the last connection to complete the circuit. Thats normal if you dont use the charging resistor that should come with it.......Sometimes its a light bulb, depends on the brand. The first time you make that final connection the cap will draw a large surge of current which creates the spark.

1984rx7roqet

ok thanks...just wanted to make sure I wasnt going to blow anything up!

David Beale

A capacitor should go across the power at the input to the audio system. The cap +ve goes to the +12V, the cap -ve goes to the ground/system ground wire. What it does is stabilize the voltage when it tries to change quickly (spikes). High audio loads can actually cause the voltage to "sag" in response to the music and the cap helps to reduce this by supplying the extra power pulses needed.

A large cap. has to build up a charge when you first apply power to it, and it has a very low internal resistance, so it will draw a huge current pulse. This will show up as a large spark, and if you have an old or marginal fuse between it and the battery it could blow that (it did on my system - a 30 Amp fuse yet). Do not remove or bypass the fuse - you need it to prevent fires or exposions. You may have to increase the fuse value a bit to accomodate the cap surges. Large caps. can also be bombs if connected backwards, hence keep the fuse .

KeithC

If its an electrolytic cap it won't explode. I've hooked a couple up backwards, no big deal. The only way to get one to explode would be to give it several times its voltage raiting. They will vent the electrolyte with some overvoltage.

1984rx7roqet

I have an 80 amp fuse and the cap is 1 Farad. The first time I blew the fuse is because I touched the pos cable to the metal on accident being a dumbass and hooking up the bbattery first. Now the fuse doesnt blow when I touch the ground, just sparks.

David Beale

KeithC, be very very careful. You may not have had one explode, but I have induced many to explode (just fooling around with old stock - electrolytics age so we were going to throw them out and I wanted to learn). They sometimes just vent as you suggest, but sometimes they go off like firecrackers (the small ones) or bombs (the large ones). It takes a lot of current to make them go "bang".