High-current 12V power supply? - Tilted Forum Project Discussion Community

skaven · 05-14-2005, 05:32 PM

I'm getting a new car soon and I won't be transferring my existing car stereo equipment into the new car. I was thinking it would be nice to use my gear as a home theater system.

I already know that car stereo components aren't as efficient as their home theater counterparts: a car is a very small space to fill with sound compared to a living room.

Nonetheless, I would like to try setting it up. To power the amps, however, requires a lot of current at 12V I'm guessing somewhere in the 30-50A range for the size amps I have and leaving some headroom for spikes. Does anybody out there have any experience with building or purchasing something like this?

I looked at Jameco and Digi-Key and found some large 12V supplies (36A with 50A peak) but they are over $200!! Surely one could simply purchase the parts to build one of these power supplies for far less.

One alternative I was considering was using a couple standard ATX power supplies: one for each amp. The 12V rails on a 350W power supply can put up 16A of current; two 350W supplies could be purchased for around $60. Simply put a load on the 3.3 and 5V rails to keep the regulators happy, and hopefully the supplies could put up enough current to run the amps at a reasonable volume.

BTW here are the equipment specs:

Sony 600W 4-channel surround amp
Sony 1200W 2-channel sub amp
2x Infinity reference 10" subs
2x Infinity reference 6-1/2" component speakers (would be front left/right)
2x Pioneer IMPP 3-way 6x9's (would be rear left/right)

For the center channel I could get a pair of small (4"?) components and run them from a modest amp, or even use the speakers already in the TV...

After all that I'd only be out ~$200 for what seems to me would be a kick-ass home theater sound system (though needlessly hacked and complicated)

Any ideas? comments?

soundmotor · 05-14-2005, 06:02 PM

Quote:

Originally Posted by skaven

Surely one could simply purchase the parts to build one of these power supplies for far less.

One alternative I was considering was using a couple standard ATX power supplies: one for each amp. The 12V rails on a 350W power supply can put up 16A of current; two 350W supplies could be purchased for around $60. Simply put a load on the 3.3 and 5V rails to keep the regulators happy, and hopefully the supplies could put up enough current to run the amps at a reasonable volume.

Any ideas? comments?

If you were setting up a demo board in a car audio shop, ideally you'd need ~2x the fused value of the amp to adequately supply it under any use condition. Although shops will squeak by with less, seeing 2x paralleled 75A Cascades behind the board is not that uncommon.

Cascade Power Supplies

For example, if the amp is fused @ 30A, your supply should be able of delivering at least 60A. You can get away with less on the amplifier running the main speakers but not for the one running the subwoofer. If the supply does not have enough grunt for the application, it will either shut down & protect itself or blow-up.

For the money you'll spend on buying supplies, hacking it together, manually switching each one on, manually switching each amp on, running wires & distro blocks, etc. you could buy a cheap home theater receiver. Put the gear aside until you are reading to re-install it in your next car, I think you will be happier.

soundmotor

merkerguitars · 05-27-2005, 11:37 AM

I might have some you can buy off of me for cheap...i'll dig around and see what I can find.

the420star · 05-30-2005, 07:43 PM

i would say you arnt going to build this thing... just to make a point some kids had to buy a power capacitor for the same amperage as what you are dealing with and it was $12 for one... $200 dosnt sound terrible especialy with all you would have... then on the same note you could sell all the stuff you have on Ebay + $200 you were going to spend and get a hell of a home stereo. It might not be as loud or what ever, but it will have dolby decoding for DTS and pro Logic, big deal if you like movies

05-14-2005, 05:32 PM	#1 (permalink)
skaven Insane Location: Austin, TX	High-current 12V power supply? I'm getting a new car soon and I won't be transferring my existing car stereo equipment into the new car. I was thinking it would be nice to use my gear as a home theater system. I already know that car stereo components aren't as efficient as their home theater counterparts: a car is a very small space to fill with sound compared to a living room. Nonetheless, I would like to try setting it up. To power the amps, however, requires a lot of current at 12V I'm guessing somewhere in the 30-50A range for the size amps I have and leaving some headroom for spikes. Does anybody out there have any experience with building or purchasing something like this? I looked at Jameco and Digi-Key and found some large 12V supplies (36A with 50A peak) but they are over $200!! Surely one could simply purchase the parts to build one of these power supplies for far less. One alternative I was considering was using a couple standard ATX power supplies: one for each amp. The 12V rails on a 350W power supply can put up 16A of current; two 350W supplies could be purchased for around $60. Simply put a load on the 3.3 and 5V rails to keep the regulators happy, and hopefully the supplies could put up enough current to run the amps at a reasonable volume. BTW here are the equipment specs: Sony 600W 4-channel surround amp Sony 1200W 2-channel sub amp 2x Infinity reference 10" subs 2x Infinity reference 6-1/2" component speakers (would be front left/right) 2x Pioneer IMPP 3-way 6x9's (would be rear left/right) For the center channel I could get a pair of small (4"?) components and run them from a modest amp, or even use the speakers already in the TV... After all that I'd only be out ~$200 for what seems to me would be a kick-ass home theater sound system (though needlessly hacked and complicated) Any ideas? comments?

05-27-2005, 11:37 AM	#3 (permalink)
merkerguitars Buffering......... Location: Wisconsin...	I might have some you can buy off of me for cheap...i'll dig around and see what I can find. __________________ Donate now! Ask me How! Please use the search function it is your friend. Look at my mustang please feel free to comment! http://www.tfproject.org/tfp/showthread.php?t=26985

05-30-2005, 07:43 PM	#4 (permalink)
the420star Psycho Location: Cow Country, CT	i would say you arnt going to build this thing... just to make a point some kids had to buy a power capacitor for the same amperage as what you are dealing with and it was $12 for one... $200 dosnt sound terrible especialy with all you would have... then on the same note you could sell all the stuff you have on Ebay + $200 you were going to spend and get a hell of a home stereo. It might not be as loud or what ever, but it will have dolby decoding for DTS and pro Logic, big deal if you like movies __________________ No, they arnt breasts, they are personalities, because its ok to like a girl for her personalities.