Power cap

**tomwheeler87** · 06-21-2006, 09:06 AM

hi there

Im a bit new to the whole car pc world. i was just wondering does a dc-dc regulator not jus do the same job as a powercap. in other words can i use a powercap with a normal 12v dc powersupply hardwired to the batery

thanks in advance
regards
Tom

**MatrixPC** · 06-21-2006, 10:25 AM

Voltage regulator and caps are 2 different things.
Voltage regulator regulate the fluctuate voltage in the car between 8-15 volts and provide a set voltage (12,9,7.5,5,...) to the equipment.
Power cap provide rush current to the equipment ( I may be wrong here).

Is it okay to use power cap with a 12VDC power supply?
If you are talking about M1-ATX, M2-ATX, Opus, DSATX as a 12VDC PSU, Yes, you can but not needed. Those PSU already have voltage regulators built -in. Just connect those PSU straight to the battery.

You need to do some more reading buddy. Head up to the newbie forum (there is a sticky regarding new to carpc) and the FAQ forum. Those answers most/all question you will be asking regarding to the whole project. It make your life easier.

**Phreak Show** · 06-22-2006, 06:19 AM

Originally Posted by MatrixPC

Power cap provide rush current to the equipment ( I may be wrong here).

Nope, you're right. Caps are used to have a constant voltage if the current is switching very fast and/or in high amounts, for example if you have a huuuuge audio system in your car

**RedGTiVR6** · 06-22-2006, 09:32 AM

and even then y ou will need a HUUUUGE cap to make a damn

**parksgm** · 06-22-2006, 12:55 PM

Originally Posted by Phreak Show

Nope, you're right. Caps are used to have a constant voltage if the current is switching very fast and/or in high amounts, for example if you have a huuuuge audio system in your car

Just to clarify...

Capacitors are used to maintain sufficient current, not voltage. While the capacitor might have some stablizing effect on the voltage, the main reason they are used is because a typical lead acid storage battery (like a car battery) cannot respond to the large, instantaneous peak current demands of a power amplifier. Most typically, capacitors are used on subwoofer amplifiers, as they demand GOBS of current when the bass "hits" in rap, rock, or simliar music.