Wiring, Stereo & Electronics Audio Components | Radars | Alarms - and things that spark when they shouldn't

how to properly charge a capacitor with a small bulb

Old 10-16-2007, 10:50 PM
  #1  
Launching!
Thread Starter
iTrader: (6)
 
HIZPANICGUY21's Avatar
 
Join Date: Aug 2006
Posts: 253
Likes: 0
Received 0 Likes on 0 Posts

Default how to properly charge a capacitor

i need help doing this (my cap came with a small charging bulb)..id hate to **** up my system or anything like that.my system is already hooked up. i just want to now add a capacitor.id like step by step instructions on how to do this.thanks everyone.HELP!!!

Last edited by HIZPANICGUY21; 10-16-2007 at 11:04 PM.
Old 10-17-2007, 12:44 AM
  #2  
TECH Senior Member
 
2MuchRiceMakesMeSick's Avatar
 
Join Date: Apr 2004
Location: Texas
Posts: 6,157
Likes: 0
Received 0 Likes on 0 Posts
Default

what exactly do you need help with? the + wire goes as close to the power drain as possible (ie the amp) the - goes to ground / bare metal. I usually use a resistor to charge caps up but in your case its a bulb. Just hook the cap to ground then take the positive wire to one side of the bulb and then the other side of the bulb to the + side of the cap until it is charged. Once it is charged hook it up like normal.
Old 10-17-2007, 01:34 AM
  #3  
Launching!
Thread Starter
iTrader: (6)
 
HIZPANICGUY21's Avatar
 
Join Date: Aug 2006
Posts: 253
Likes: 0
Received 0 Likes on 0 Posts

Default

ok..so do i remove the fuse (near the battery), then disconnect the ground from the amp and connect it to the - on the cap. then run the power to one side of the bulb and the other side of the bulb to the + side of the capacitor then place the fuse back in place? this will charge the cap?see picture below



when its all charged up..is this the correct way to hook it all up.see picture below


Last edited by HIZPANICGUY21; 10-17-2007 at 01:40 AM.
Old 10-17-2007, 07:38 AM
  #4  
TECH Fanatic
 
pentavolvo's Avatar
 
Join Date: Nov 2006
Posts: 1,273
Likes: 0
Received 1 Like on 1 Post

Default

an easier way is hook everything up how you would want it wired but dont put the fuse in. go under the hood and put the light in place of the fuse wait for it to finish charging then take the light out and put the fuse in, did it like this at work all the time
Old 10-17-2007, 09:23 AM
  #5  
TECH Enthusiast
iTrader: (1)
 
95bat's Avatar
 
Join Date: Jul 2005
Posts: 524
Likes: 0
Received 0 Likes on 0 Posts
Default

Do you listen to anything people say? Leave the cap off, it will not help your system.
Old 10-17-2007, 12:46 PM
  #6  
TECH Resident
 
Shane's Avatar
 
Join Date: Jan 2002
Location: central TX
Posts: 859
Likes: 0
Received 0 Likes on 0 Posts

Default

Just for my curiosity...what happens if the cap is not pre-charged?
Old 10-17-2007, 12:57 PM
  #7  
TECH Fanatic
 
pentavolvo's Avatar
 
Join Date: Nov 2006
Posts: 1,273
Likes: 0
Received 1 Like on 1 Post

Default

big spark at hook up... but for real a cap is a waste
Old 10-17-2007, 02:01 PM
  #8  
TECH Apprentice
iTrader: (17)
 
kmgsix08's Avatar
 
Join Date: Aug 2006
Location: Ft. Worth, TX
Posts: 366
Likes: 0
Received 0 Likes on 0 Posts
Default

cap kept my lights from dimming and made everything sound better...
Old 10-17-2007, 02:04 PM
  #9  
TECH Resident
 
Shane's Avatar
 
Join Date: Jan 2002
Location: central TX
Posts: 859
Likes: 0
Received 0 Likes on 0 Posts

Default

Yeah, I'm curious what the argument is against a cap?

I have a cap...but I still have headlight-dimming issues...
Old 10-17-2007, 02:19 PM
  #10  
TECH Apprentice
iTrader: (11)
 
00CaliforniaZ28's Avatar
 
Join Date: Nov 2001
Location: Granada Hills, CA
Posts: 331
Likes: 0
Received 0 Likes on 0 Posts
Default

I always thought the point of a cap was to give your amp(s) a steady supply of power to draw from, keeping your sound more consistent. This wouldnt have an effect on the headlight issue as the lights are still drawing current from the same source. However the cap is always full, so the amp always has a full bank of power to draw from, even if the battery/alternator is being taxed. Kind of like those doggy water bowls, with the big tank on top... As the dog drinks the water, the tank refills the water in the bowl the second that its drunk, so theres always a constant level of water in the bowl. Without the tank(cap) then the water level would go down until its filled from another source (the sink or battery/alternator ).... if that makes any sense
Old 10-17-2007, 05:10 PM
  #11  
Restricted User
iTrader: (2)
 
MikeFbody's Avatar
 
Join Date: May 2006
Location: south central PA
Posts: 457
Likes: 0
Received 0 Likes on 0 Posts
Default

your are correct, except, in your example with the doggy bowl, the cap is a thimble. They just don't hold enough power to be useful in most situations. They discharge very fast, which is good, but the amount of current discharged is just not enough to make an audible difference. A measurable one with test equipment, sure, but not big enough to hear.
Old 10-17-2007, 07:22 PM
  #12  
TECH Enthusiast
iTrader: (1)
 
95bat's Avatar
 
Join Date: Jul 2005
Posts: 524
Likes: 0
Received 0 Likes on 0 Posts
Default

Not even a thimble in a doggy bowl.
The amount of USABLE energy in a 1 farad cap is 49 joules at 14 volts. That means it can supply 49 watts for 1 second before it is totally drained. Or, 1 watt for 49 seconds before totally drained. Stereo systems dont operate below 11 volts (normally 12, but we'll say 11 just in case), so the actual usable amount is closer to about 30 joules. With the OP's 500 watt amp, it will power the amp for 3/50ths of a second.

In comparison, an optima yellow top stores 2,574,000 joules. How much do you guys think 30 joules will help a stereo when it has 2.5 MILLION in the battery? A battery that is only used when the alternator can't keep up?


Thread Tools
Search this Thread

All times are GMT -5. The time now is 03:59 AM.