wiring question

[paikiah 5,000+ posts]

I'm about to install my brax 1F cap into my system...

do I HAVE to charge it first? SOmeone in another forum said it was necessary...

really? Can't I just install it? Wouldn't it charge naturally, once the cap is in the system?

//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[Alaxan 5,000+ posts]

You do need it to charge once installed and before you turn the system on. But that is simple enough. a test light should be replaced by the inline fuse and it should be bright and die out as the cap charges. Replace the fuse when done and enjoy.

 

[maylar 10+ year member]

Originally posted by excelonperu A cap doesnt add stress to the system, since their resistance is so low (0.001 ohms) they dont consume any energy, they just supply an electrical charge when it is needed, but they can only supply it for a very short period of time (less than a second) they charge themselves and discharge in very short periods of time because of its low resistance. When an engineer designs a cap It must have low resistance, so they dont add stress to the system, and they dont are the solution for a weak alternator. They are the solution for systems that run ok, but have their lights dim when heavy bass comes.

The only thing that consumes energy are resistances and impedances, cause they are measured in ohms. A farad is a unit of capacitance not of resistance.

Any more proves??

You haven't got a clue. What do you think "impedance" is?

 

[MikeofTulsa Moderator]

another cap debate....i'll stay out of this one....//content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[excelonperu 10+ year member]

Originally posted by maylar You haven't got a clue. What do you think "impedance" is?

Impedance:

Z=squared root of: R(sqrd) +(Xl-Xc)(squared)

Its units are ohms

 

[maylar 10+ year member]

Originally posted by excelonperu Impedance:

 

Z=squared root of: R(sqrd) +(Xl-Xc)(squared)

 

Its units are ohms

Good. And Xc is what? Capacitive reactance:

Xc = 1 / (2 x Pi x f x C)

Which means Capacitance has an impedance (in ohms) that is frequency dependant. At DC ( zero Hertz, f=0) a capacitor has infinite impedance and draws no current. But while it's charging, the voltage is changing, and it draws current:

I = C dv/dt

I = amps

C = Farads

dv/dt = rate of change of voltage (volts/sec).

That current comes from the alternator.

 

[excelonperu 10+ year member]

I know what capacitive reactance is, I said they have a very small amount of resistance, but they are designed in a way they have very little resistance, so you shoul know that the lower the resistance, the shorter the time it will take a capacitor to charge or release its current.