power supply

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=119918
Printed Date: May 13, 2025 at 3:59 AM

Topic: power supply

Posted By: segal79_19
Subject: power supply
Date Posted: February 05, 2010 at 1:41 PM

i am looking for a formula to determine what size power supply i will need to run.

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Marks Auto Mart Sound and Accessories
2100 5th Ave. South
Fort Dodge Iowa 50501

Replies:

Posted By: DYohn
Date Posted: February 05, 2010 at 1:58 PM

segal79_19 wrote:

i am looking for a formula to determine what size power supply i will need to run.

A formula? And what sort of power supply are you talking about?

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Posted By: segal79_19
Date Posted: February 05, 2010 at 2:19 PM

sorry i am looking for a way to determine what size power supply i will need to run equipment for display purposes. example would be a tool cart i installed a stereo on. single deck 4 speakers and a small sub amp set up, but i also have much bigger things. running multiple head units and amps on my display wall. with an electronic switcher. simular to a best buy display.

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Marks Auto Mart Sound and Accessories
2100 5th Ave. South
Fort Dodge Iowa 50501

Posted By: DYohn
Date Posted: February 05, 2010 at 2:45 PM

Add up the wattage requirements of all the gear you intend to power. The input wattage (or current which you can then convert to wattage) required should be in any gear's owner's manual...

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Posted By: segal79_19
Date Posted: February 05, 2010 at 3:48 PM

so a deck at 10 amp fused and an amp at 25 amp fused requires a 504 watt power supply running at 14.4. that seems like a fairly big power supply. i think i am missing something

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Marks Auto Mart Sound and Accessories
2100 5th Ave. South
Fort Dodge Iowa 50501

Posted By: DYohn
Date Posted: February 05, 2010 at 4:30 PM

segal79_19 wrote:

so a deck at 10 amp fused and an amp at 25 amp fused requires a 504 watt power supply running at 14.4. that seems like a fairly big power supply. i think i am missing something

35 amps @ 14.4 VDC = 504 watts. That's right.

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Posted By: oldspark
Date Posted: February 06, 2010 at 3:46 AM

I totally agree in the absence of more info.

It may be the 35A is at 13.8V (483W) or at its lowest operation voltage - say 8V (280W).

And the fuses may cater for peak inrush currents.

And maybe the amp is never above 20% power consumption etc (but unless you lock the loud dial, someone will take it to 110!).