CAR AUDIO : Determine Your Ampere's Pull

[andrewan]

This is all Information I myself have gathered from the MECP Installers Guide book.

Alright Here's the Question!

I am trying to figure out how much pull on my alternator I am getting from the amp.

Here is the formula We use to figure this out


I = (Po - n*Po + Po) / V

Now

I = amperes
Po=RMS
n=efficiency
V=voltage

So for me its:

I = (3000 - .8*3000 + 3000) / 13.8

So I do this

3000*.8 and i get 2400


3000-2400=600

600+3000

3600/13.8

260.87 This is my amperage draw correct?



and if I'm correct for everyone else heres an easier equation for this:

I = (2-n)Po/V


So for me this would go

1. 2-.8 =1.2

2. 1.2*3000=3600

3. 3600/13.8

And there we go. 260.87!!!!!


Now, We must remember that Most Class D Amplifiers have a 80% Efficiency Rating and Most Class A/B Amplifiers have a 60-70% efficiency Rating!

[Jean]

So you have a 3000 watt rms amp?

Also keep in mind music isn't all pure sinewaves.... unless you are driving around listening to test tones cranked all the way up lol