[marcus]

Nick,

I've thought about this on and off for about five years.

Yes, it's certainly possible. It merely needs a 12V to 36-0-36V DC to DC converter. These things are not too difficult, but they require purpose built magnetics, which can be elegantly sidestepped with a dual 120Vac to 40-0-40Vac toroid working backwards at lowish frequency, say up to about 1000Hz. This can actually be made very economically using special chips, but there's a bit of R&D in it. The idea of using a mains toroid backwards is not new, but it means costs can be reigned in considerably.

Cheers,

Hugh

Hi Hugh and all

Hugh, I read with interest that you have considered developing an AKSA car audio amp - something I would be very interested in building.  For now, what do you think of the power supply (below) designed by amp_man_1 as a possible power supply for the AKSA. (http://www.diyaudio.com/forums/showthread.php?s=&threadid=31614&perpage=10&pagenumber=6[/url])

Would this design need any modifications/additions for the AKSA?

thanks

[Martin]

Seeing that Hugh has such a passion for autos, I've often wondered
just what kind of audio system he does have in his car.
 Probably just a drivers seat....a stack of Aksas passenger side and
6 Aksonics across the back.....hummmm...

I'll let ya'll know how it sounds!
   

Martin

No kidding, we actually do stuff like this in Oklahoma!  

[AKSA]

Martin,

If only you knew.......  behold the mechanic's car.  I own a 250 CID Ford Falcon, a lovely old car I have built myself, buying the body with a broken engine, and moving a good engine, transmission, brakes and suspension into it myself.  I do not have a sound system in the car, but recently I replaced the camshaft in it to run on LP gas.

DC-to-DC converters are an interest of mine.  However, the problem is the high frequency transformer (typically this operates at 40KHz), which is tricky to wind without special machines.  As in all things, I try to use parts easily available, and the most obvious parts are toroidal transformers designed for mains operation.  If you use a 160VA transformer with dual 120V windings, and 40-0-40V secondaries, you can in fact reverse the transformer and operate it very nicely backwards.....

It is not commonly known, but toroidal transformers operate very well at around 200Hz.  At this frequency, the filter capacitors can be made very small, around 3uF per watt of amplifier power.  This gives you a means of transforming the voltage without using complex, pulse width modulation devices such as Amp_Man's SGS chip, which is very good, but which create a spray of high frequency artefacts which are tricky to remove from the rail.

Cheers,

Hugh