Capacitors

[Prowler]

i just won a 1 farad lightning audio capacitor off ebay for $23. now I know they're put in line with the cable from the battery, and it'll stop my headlights from dimming when my small system hits and make it sound a little bit better. but how exactly do i hook it up? what type of connectors are used on the capacitor? how much is an "install kit"? how much is a digital voltage reader and are they recommended? should i notice a big difference in the sound? how do i mount this?

this is the pic from the auction.

 

[TurboMirage]

oh my god. lightning audio... that is probably the biggest fire hazard ever.


i think they need to be charged before you install them, though.

 

[liquid00meth]

Capacitors are wires in series with the regular power input of your amp. You send the power wire from your battery to the capacitor terminal, as well as all the power wires to the amp(s). So they all connect to the same terminal. Connect the ground wire of the capacitor, as well as the ground wire of your amps normally. that's all.


BUT, you MUST CHARGE THE CAPACITOR FIRST with a 12v hookup and a 1k resistor. Any stereo shop would probably be able to do this for you.

 

[rudeludenotmeanthough]

Why MUST you charge it? It does charge when you install it. so..

why..??

 

[rudeludenotmeanthough]

Originally posted by liquid00meth@Oct 28 2003, 05:13 PM
Capacitors are wires in series with the regular power input of your amp.  You send the power wire from your battery to the capacitor terminal, as well as all the power wires to the amp(s).  So they all connect to the same terminal.  Connect the ground wire of the capacitor, as well as the ground wire of your amps normally.  that's all.


BUT, you MUST CHARGE THE CAPACITOR FIRST with a 12v hookup and a 1k resistor.  Any stereo shop would probably be able to do this for you.

Here this is just to clarify a bit...

Its really simple.

EDIT: oh yea install equipment.

All you need are Wire connectors (eye) and 8 gauge wire.

Use a hammer, and flat tip screw driver, to securely attatch the wire connectors to the wire. Simply trying to squeez teh connector closed is will NOT make it secure enough. And you really dont want the Positive wire to fall off.

as for mounting the CAP itself, you can use some Pipe holder clamps. They fasten down around the cap and attach to a board or seat or metal or whatever.

Install kits usually run about 35 to 40 bucks. All the equipment in the kits (ie connector, wire, etc.) can be bought seperatly for less. Wire from a home imporvment store, and connectors from radiosshak.... whatever.

hope this helps, good luck

Sorry its late, and i cant remeber the name of shit. Im edit this later on.

EDIT 2: i think that paint pic deserves a Sticky.. haha... ummm ok nm

 

[Prowler]

thanks, that helps a lot.

so do i have to charge the cap before hand or not?

 

[MaliWho97]

Yes, the cap must be charged first to have full potential. I'd recommend going to their website and emailing their tech department before you try anything, some caps charge different than others. Use the recommended wire size that your amp uses, you can tell by the size of the power terminal on it. Run the power to the positive side of the amp, and from the positive to the amp, then run a single ground wire of the same gauge to a clean, bare metal sold chassis location, and try to keep the ground under 18 inches if possible... Keep the cap close to the amp, its more efficient that way. You can get the charge light or resistor, whatever they recommend, at radio shack. Hope this helps.

 

[liquid00meth]

the reason you need to charge it is so that it doesn't charge instantly when you connect it. By charging it with a resistor, you effectively just charge it much more slowly, so that it can reach it's full potential without damaging any of the capacitor internals

 

[rudeludenotmeanthough]

Originally posted by liquid00meth@Oct 31 2003, 03:49 PM
the reason you need to charge it is so that it doesn't charge instantly when you connect it. By charging it with a resistor, you effectively just charge it much more slowly, so that it can reach it's full potential without damaging any of the capacitor internals

ok now i understand. SO YES.. charge the beast.

 

[luder22]

a capacitor is a short at low or 0 volts so if you connect a dead cap to a battery you might as well throw a crowbar across your battery because electrically its the same. charge the cap first monitor it with a voltmeter

 

[rudeludenotmeanthough]

Originally posted by luder22@Nov 19 2003, 11:15 PM
a capacitor is a short at low or 0 volts so if you connect a dead cap to a battery you might as well throw a crowbar across your battery because electrically its the same. charge the cap first monitor it with a voltmeter

ok that makes sense... what should be used to slowly charge it?

 

[hcivic.com]

a resitor or bulb

 

[Prowler]

Originally posted by rudeludenotmeanthough+Dec 5 2003, 12:54 AM-->

luder22

@Nov 19 2003, 11:15 PM
a capacitor is a short at low or 0 volts so if you connect a dead cap to a battery you might as well throw a crowbar across your battery because electrically its the same. charge the cap first monitor it with a voltmeter

ok that makes sense... what should be used to slowly charge it?

my local car audio place said it would just arch a little if not priorly charged, but the cap would charge fine anyways. and it did, i can notice quite a difference.

 

[rudeludenotmeanthough]

nice to hear you got it done... got any pics of the install?

 

[CRX-YEM]

Um I can see there is a lot of mis information here.

A capacitor is not a dead short when it's not charged I can assure you that.
A capacitor is some material of some unit of area seperated by a dielectric. In theory the cap should have no resistance but in fact they do.

When a capacitor is connected to a voltage source it will charge to the source voltage instantaniously which can draw a lot of current (if it's avaliable). in the case of using a car battery to charge the cap the potential to draw upwards of 50 AMPS Quesent current is possible, which could easily be above the ratting of the wires you might be trying to use and in the end actually melt the wires.

So a safe way to charge the battery and to limit current would be to use a series resistor connected to the voltage source and then to the Cap and then connecting the circuit to slow down the charge cycle and limit the current.

Charge Time
T=R*C
T is in Seconds
R is in Ohms
C is in Farads

Imax=V/R
V is in volts
R is in Ohms
I is in Amps

Power=V^2/R
P is in Watts
V is in Volts
R is in Ohms

So to safely charge your capacitor I'd say no more than 1AMP is a good
rule of thumb as a 12 gauge wire will easily be able to carry an AMP

so if your using a car battery the source voltage is 12V. now lets see what resitor will limit your current draw to one AMP

Imax = 12V / 12 Ohms
the problem here is the power dissipated by the resistor is going to be quite high using P=V^2/R, 144/12= 12 Watts
so you'd need a 12 Ohms 12 Watt resistor to safely charge the cap. which won't be easy to come by.

so we need to be a little more conservative and use a larger resistor to lower the power which will increase charge time.

1/4Watt resistors are really easy to find so lets see what's avaliable.

P=.25, V=12, R=? : R=V^2/P : 144/.25 = 576 ohms so double the value and look for at least a 1Kohms 1/4 watt resistor.

The quiesant current that will be drawn at initial charge up will be
I=V/R , 12/1000 = .012 Amps or 12mA this is a much safer limit.

The total time to charge the cap will be
T=RC for one time constant and it take 5 time constants to charge a capacitor to 95% of the source voltage.
so you're looking at T=RC : 1000Ohms * 1 Farad = 1000 seconds
for one time constant so total charge time will be 5000 seconds or 1.4 hrs.


|-------| (---------/\/\/\---------|
| |
|-------+Bat -Bat------------|

The capcitors symbol the | side is positve
+|(-


***** keep in mind do not hook this capacitor up backwards as it had to poles on positive and one negative, if you hook it up backwards you risk the chace of blowing it up *****

reference for symbols

 

[Prowler]

Originally posted by rudeludenotmeanthough@Dec 5 2003, 07:04 PM
nice to hear you got it done... got any pics of the install?

i'll get a picture today or tomorrow. remind me on AIM.

 

[seanjuan]

Originally posted by CRX-YEM@Dec 5 2003, 08:49 PM
Um I can see there is a lot of mis information here.

A capacitor is not a dead short when it's not charged I can assure you that.
A capacitor is some material of some unit of area seperated by a dielectric. In theory the cap should have no resistance but in fact they do.

When a capacitor is connected to a voltage source it will charge to the source voltage instantaniously which can draw a lot of current (if it's avaliable). in the case of using a car battery to charge the cap the potential to draw upwards of 50 AMPS Quesent current is possible, which could easily be above the ratting of the wires you might be trying to use and in the end actually melt the wires.

So a safe way to charge the battery and to limit current would be to use a series resistor connected to the voltage source and then to the Cap and then connecting the circuit to slow down the charge cycle and limit the current.

Charge Time
T=R*C
T is in Seconds
R is in Ohms
C is in Farads

Imax=V/R
V is in volts
R is in Ohms
I is in Amps

Power=V^2/R
P is in Watts
V is in Volts
R is in Ohms

So to safely charge your capacitor I'd say no more than 1AMP is a good
rule of thumb as a 12 gauge wire will easily be able to carry an AMP

so if your using a car battery the source voltage is 12V. now lets see what resitor will limit your current draw to one AMP

Imax = 12V / 12 Ohms
the problem here is the power dissipated by the resistor is going to be quite high using P=V^2/R, 144/12= 12 Watts
so you'd need a 12 Ohms 12 Watt resistor to safely charge the cap. which won't be easy to come by.

so we need to be a little more conservative and use a larger resistor to lower the power which will increase charge time.

1/4Watt resistors are really easy to find so lets see what's avaliable.

P=.25, V=12, R=? : R=V^2/P : 144/.25 = 576 ohms so double the value and look for at least a 1Kohms 1/4 watt resistor.

The quiesant current that will be drawn at initial charge up will be
I=V/R , 12/1000 = .012 Amps or 12mA this is a much safer limit.

The total time to charge the cap will be
T=RC for one time constant and it take 5 time constants to charge a capacitor to 95% of the source voltage.
so you're looking at T=RC : 1000Ohms * 1 Farad = 1000 seconds
for one time constant so total charge time will be 5000 seconds or 1.4 hrs.


|-------| (---------/\/\/\---------|
| |
|-------+Bat -Bat------------|

The capcitors symbol the | side is positve
+|(-


***** keep in mind do not hook this capacitor up backwards as it had to poles on positive and one negative, if you hook it up backwards you risk the chace of blowing it up *****

reference for symbols

this should be stickied for real
sounds like a damn text book
and i bet no one knows that shit.... I didn't and I've had two years of college phyisics and one year of circuits.... but that was a few years ago so chances are I knew it but just forgot it <_<

 

[CRX-YEM]

thanks for the props, having 4 years of industrial electronics in high school, and studing physics, mechanics, electronics in college kind of helps and imbeds this stuff in your head.

 

[K2e2vin]

Originally posted by CRX-YEM@Dec 15 2003, 05:15 PM
thanks for the props, having 4 years of industrial electronics in high school, and studing physics, mechanics, electronics in college kind of helps and imbeds this stuff in your head.

can you name all the numbers each color represents on a capacitor right quick? thank you!

 

[CRX-YEM]

ok that's one color code I'd have to look up because almost all well 80-90% of em are marked like 103K (which would be 10uF) which is the IEC Code

but if I not mistaken capacitors use the same color code as resistors
which would be as follows
Black 0
Brown 1
Red 2
Orange 3
Yellow 4
Girls 5
Blue 6
Violet 7
Grey 8
White 9

an easy way to remember
Bad Boys Rape Our Young Girls But Violet Gives Willingly