Power supply question..

Beau · 18th July 2003, 04:15 AM

I have a class D car amplifier that produces about 1200wrms, (1 Ohm , mono) now have a wife = no car stereo any more so i would like to use it in a home system. So my question is what sort of transformer/ torroid etc do I need (240v Mains)??
TIA, Beau.

hacknet · 18th July 2003, 11:27 AM

if its a really 1200w mono... u need hell lotsa power even if it was 99% effiecent. i think the average class D puts out about 30% of heat.

so....

1200/70 * 100% =~1714w

u need about 1714w.

1714w/12v = 142 Amperes

u need 12v at 142 Amperes. good luck at getting a power supply to suit ur requirements.

on the other hand, i doubt the amp is 1200w RMS. i bet is a mini 100w.....

u`ll do ok with a pentuim4 psu.

Matttcattt · 18th July 2003, 04:55 PM

Quote:

Originally posted by Beau
I have a class D car amplifier that produces about 1200wrms, (1 Ohm , mono) now have a wife = no car stereo any more so i would like to use it in a home system. So my question is what sort of transformer/ torroid etc do I need (240v Mains)??
TIA, Beau.

Quote:

Originally posted by hacknet
if its a really 1200w mono... u need hell lotsa power even if it was 99% effiecent. i think the average class D puts out about 30% of heat.

so....

1200/70 * 100% =~1714w

u need about 1714w.

1714w/12v = 142 Amperes

u need 12v at 142 Amperes. good luck at getting a power supply to suit ur requirements.

on the other hand, i doubt the amp is 1200w RMS. i bet is a mini 100w.....

u`ll do ok with a pentuim4 psu.

it says 1200w at 1 ohm. he wont be using 1 ohm speakers.

hacknet · 19th July 2003, 01:03 AM

those large woofers some times dip down to 1 ohm... lets play safe... since they are ment to drive 4 ohmz. the likelyhood of them going down to 1 ohm is very high.

Beau · 21st July 2003, 03:43 AM

I am using 3 Dual 6 ohm subs in parallel= 1Ohm, And the amp has been independantly tested, it came out at 1232wrms AT 14v, 1%distortion.

hacknet · 21st July 2003, 09:45 AM

may i ask how did u test it?

Beau · 22nd July 2003, 03:37 AM

I didnt personally, it was in Car audio & entertainment, by their lab.

jan.didden · 22nd July 2003, 09:29 AM

Quote:

Originally posted by Matttcattt

it says 1200w at 1 ohm. he wont be using 1 ohm speakers.

Whatever it is, it will for sure not be 1200W continuous. If it was, you'll loose the car doors before the battery runs out. Not to mention the internal cranium heamorrage.

Jan Didden

hacknet · 22nd July 2003, 10:38 AM

1200w on 50db/w speakers....

plus... do you trust those labs... at 1200w. the internal smps has to be hell of a chunky... i don`t think so...

millwood · 22nd July 2003, 12:51 PM

Quote:

Originally posted by hacknet
at 1200w. the internal smps has to be hell of a chunky... i don`t think so...

yeah. 1200w at 12v means 100 amps. Most batteries are rated about 50amp cold crank amps (for a brief period of time), and most alternators are rated 85amps.

18th July 2003, 04:15 AM	#1
Beau diyAudio Member Join Date: Jul 2003	Power supply question.. I have a class D car amplifier that produces about 1200wrms, (1 Ohm , mono) now have a wife = no car stereo any more so i would like to use it in a home system. So my question is what sort of transformer/ torroid etc do I need (240v Mains)?? TIA, Beau.

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18th July 2003, 11:27 AM	#2
hacknet diyAudio Member Join Date: Nov 2002 Location: sg	if its a really 1200w mono... u need hell lotsa power even if it was 99% effiecent. i think the average class D puts out about 30% of heat. so.... 1200/70 * 100% =~1714w u need about 1714w. 1714w/12v = 142 Amperes u need 12v at 142 Amperes. good luck at getting a power supply to suit ur requirements. on the other hand, i doubt the amp is 1200w RMS. i bet is a mini 100w..... u`ll do ok with a pentuim4 psu.

19th July 2003, 01:03 AM	#4
hacknet diyAudio Member Join Date: Nov 2002 Location: sg	those large woofers some times dip down to 1 ohm... lets play safe... since they are ment to drive 4 ohmz. the likelyhood of them going down to 1 ohm is very high.

21st July 2003, 03:43 AM	#5
Beau diyAudio Member Join Date: Jul 2003	I am using 3 Dual 6 ohm subs in parallel= 1Ohm, And the amp has been independantly tested, it came out at 1232wrms AT 14v, 1%distortion.

21st July 2003, 09:45 AM	#6
hacknet diyAudio Member Join Date: Nov 2002 Location: sg	may i ask how did u test it?

22nd July 2003, 03:37 AM	#7
Beau diyAudio Member Join Date: Jul 2003	I didnt personally, it was in Car audio & entertainment, by their lab.

22nd July 2003, 10:38 AM	#9
hacknet diyAudio Member Join Date: Nov 2002 Location: sg	1200w on 50db/w speakers.... plus... do you trust those labs... at 1200w. the internal smps has to be hell of a chunky... i don`t think so...