figuring amperage draw

[TonyV225]

Is there a site that explains how many amps are needed for what power output ??? Or is this even close what i have here?? to me it seems not so correct. They say most cars alternator only uses 60% of the alternator leaving 40% left over for other uses For Example:

Alternator = 80 Amps 80 x .40 = 32 Amps

Please keep in mind this is an estimate only and not exact science. It is best to get your electrical system tested by a professional to determine the electrical system's true capabilities.

Calculating Amplifier Current Demands

By using the fuse value of the amplifier you can get a rough idea of the amount of current draw that will be used under full output power. Although the full output rating is good to determine the total amperage draw in the system, it does not represent the true continuous or averaged amperage draw in the system. Listed below is a simple way to determine the approximate continuous current draw of your amplifier.

1.) Determine fuse value of the amplifier.

2.) Divide the RMS power Rating by the Peak power rating.

Example:

50Watts RMS Divided by 100 Watts Peak Power = .50 (50%)

Once you figure the percentage of RMS vs. Peak power, you multiply the fuse value of the amplifier by the RMS percentage.

Example:

If the amplifiers fuse value was 30A, then 30A multiplied by 50% would be 15A of continuous current draw

 

[paws264]

Whew, that was a lot of mental gymnastics; Tony, my "Calculator-breath" friend, why not just get one of these and then you can measure the current without even interrupting the line.

Mel

 

[Moleculo]

You can easily figure out the current needed under peak conditions by using Ohm's law and factoring in the efficiency of the device. For example, for 100 watts power output running on 14 volts, take 100 / 14 = 7 amps. But no amp or rig is 100% efficient, so you have to factor the current consumption for power dissipated as heat. A typical class C amp is about 65% efficient, while a class AB will be only about 50% efficient. So for a class AB amp, finish the equation by taking 100 / 14 / .5 which tells you that you need 14 volts under peak conditions. Keep in mind, that you are probably not transmitting for long periods at peak power output. Because the human voice doesn't always cause peak power, you actually need a bit less power for everyday use, which is why in our example, it will probably work fine at 10 amps or so.

 

[Beetle]

Think you mean 14 amperes, not volts... :?:

 

[C2]

that and, i still look at peak draws because even though the average is less, the peak is what matters.

 

[Moleculo]

Think you mean 14 amperes, not volts

Yeah, you guys knew what I meant. LOL See what happens when you drink whiskey while trying to talk about watts, amps, volts, and other radio mumbo jumbo?

 

[TonyV225]

LMA Now mole imagine theres cb techs that do exactly that " See what happens when you drink whiskey while trying to talk about watts, amps, volts, and other radio mumbo jumbo? "