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Adding an ADC to the chassis

PostPosted: Mon Mar 02, 2009 4:42 pm
by stevens
I'm planning to add an analog to digital converter(texas instruments pcm4222 evm) to my half full seventh circle chassis (which i'm extremely happy with). the whole circuit is there, it just needs a box and a power supply, for which i'm planning to use the PS03.

I would need to build a regulator circuit for it I think. It needs +/-15v for the analog section, and +5v for the digital section. I'm thinking for the +/-15v I can build a circuit just like the one used by the C84: http://www.seventhcircleaudio.com/C84/C84R19/docs/c84_sch.pdf and use the +/-30v

I need some advice on how to get +5v. Can I regulate 48V down to 5V? Can I just use another 317 and another of that same circuit, but just the + half? Or is that too much power to dissipate?

Or can I just get the +5v from the same +30v I'm using for the 15v?

I don't know much about circuit design, just the basics. Should I read up on anything before attempting this project? I'm open to book suggestions. Thanks in advance!

-Steve

PostPosted: Tue Mar 03, 2009 1:32 pm
by DPLight
For a 5VDC supply I'd probably just go with a 7805 regulator and come off the +30 supply. Of course you'd have to make sure you are not overloading the PS03.

PostPosted: Fri Mar 06, 2009 1:18 pm
by stevens
cool, thanks so much! that will be a lot simpler. i don't think i'll have a problem with overloading, it only draws 200ma for each side, so 400ma plus whatever the digital part draws (probably not much right?)

i've slightly changed my plans to setting this thing up in a separate enclosure, but still using PS03, running out of one of the unused holes in the chassis and into the other box.
i'll let you know how it turns out!

PostPosted: Mon Mar 09, 2009 10:22 am
by tpryan
i've slightly changed my plans to setting this thing up in a separate enclosure, but still using PS03, running out of one of the unused holes in the chassis and into the other box.


I liked your first idea better. If you're using a separate enclosure, why not just run the A/D from a decent wall-wart?