Dual 1176 - Power supply enough?

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

kdawg

Well-known member
Joined
Jun 9, 2004
Messages
129
Location
California
I'm putting together two G1176 boards in one chassis but wanted to know if one toroidal transformer is enough to power both? I've got 1 22V 1.136A toroidal... will I have any ground issues also? Thanks

-kdawg
 
does it have a center tap?
won't light up many lamps, ie VU meter lamps, pilot lights, etc
ground no problem, maybe some additional pi filtering to eliminate cross talk
someone has done this so hang in there!
:thumb:
 
I also did this with my dual Calrec EQ, but I haven't tested it yet other than seeing the lights light up - you had some crosstalk issues with something similar?

I'm using 4 white LEDs per board for meters, so 8 total. Think enough current with the regulators?

Yes - it has center tap

-kdawg
 
Hey...

I'm wondering this n all - Would it be worth leavin the psu circuit out on both boards and makin a sep psu board with an LM317 (higher current rating the 7824?) and some bigger caps to power both boards....?

Cheers
 
I think in doubler circuits like this it is best to put a large value bleeder resistor across each of the input filter caps (C1 and C2) to make sure voltage is distrubeted evenly on each cap.
 
Hey Thomas

Like so?:

bleeder-fix.jpg


Cheers :thumb:

BTW, should they be 5 watters like R1 too? and should that R2 (100r) be a 5W too?
 
Almost, but connect the R13 across C2 instead of to ground. Most capacitors have a much larger tolerence than the resistors so this just helps the circuit ballance better.
 
great - thanks... :thumb:

Just a cpl things to clear up -

1. That value of 220K ok?
2. Should these resistors (and R2/100R) which are placed before the vregs all be 5 watters as is R1 already? Guess it cant hurt neways...

Ta
 
220K is fine. 1/2W is OK for this. Not sure how much current draw for R2 so I will wait for someone who knows to answer.
 
coo, here's the ammended layout so far:

dual1176_psu.jpg


will be etching a few bits tomorrow and will do one of these n all if the layout is acceptable :thumb:
 
Back
Top