class a/b or class D ?? 1000 watts tops?

 

Based on 14.4 volts and a class A/B amp with 50% efficiency I would say around 575 watts.

A class D with 80% efficiency about 920 watts.

Of course the fuse would probably heat-up and eventually blow when passing current at its rating.

You could most likely achieve more wattage for short periods of time before the fuse blows.

Kevin

 

good input. i appreciate that.

how long do u think an 80amp fuse would hold up for while its being driven at full till by either class a/b and class D ?

yah i know i would get more wattage in short instances but i am concerned with a continuos use situation.

[ January 12, 2005, 02:16 AM: Message edited by: Father Yuli ]

 

If the fuse is being used to its max rating it will not make a differance what type of amp topology it is...80 amp draw is 80 amp draw.

All I know is it would blow eventually....probably the best way to test how long the fuse would last would be to get your timer and amp meter out and test it. It might be easier to test for this on a bench with some dummy-load resistors.

Kevin

 

I once did a test about a year ago.. we took an amp with 4 40 amp fuses.. burped it.. then put in 4 30 amp fuses.. burped it.. then put in 4 20 amp fuses.. burped it.. then 4 10 amp fuses and burped it.. then 4 5 amp fuses.. burped it..

all of the scores were the same results on my termlab.. the only diff is in some of the tests they blew, some didn't..

 

btw.. this was an atomic 1500 watt amp..

 

C'mon Yuli.. you know the answer to this. It's basica math. You're probably just too lazy to do it yourself [img]tongue.gif[/img]

14.4 x 80 = 1152.

Now.. this is at 100% efficiency, which no amp can achieve. A generally accepted figure for a class A/B amp is %50 efficiency. BUT to blow a fuse you apparently need double the power for something like 2 or 5 seconds. So ,for the sake of argument, cut the power in 1/2, but double the fuse rating. It all works out.

So on an 80 amp fuse at 14.4v you can get ABOUT 1150w. (we're dealing with electronics, so nothing is concrete in these ratings)

Now.. if we take a class D amp at 80% efficiency.

14.4 x 80 = 1152

80% efficiencey = 920w

Now.. again you can get about double the power out of an 80A fuse.

14.4 x 160 = 2304

80% eff = about 1840w.

So for a class a/b you could get about 1150, for a class D you could get about 1800.

Sound good?

 

Jordy thats too much writing, u are a nerd.

yah i know u can pull twice the power from a fuse, but can u do it for 30 seconds straight?

 

generally, if you're running that much more through a fuse than it's rated for it'll blow, the problem is that each fuse will take a slightly different amount of time.

 

as long as the fuse blows approximately when its supposed to thats good.

so u guys think about 1000 watts is the tops that can go through 80 amp fuse?