Simple Power Supply Stuff

[MACHINE MEDIA]

> The PS uses a transformer from Electronics Goldmine which has three
> secondaries: 
> 28 VCT @ 2A, 18 VCT @ 1A, and 16 VCT @ 2A.  I'm running the 28VCT into a
> bridge and into a LM317 and LM337 trimmed to +-15VDC. Yes, it does have the
> necessary caps and resistors.  I know that the ASM-1 doesn't need +5V, but I
> have the 16VCT winding running into a LM7805 (just using the center tap and
> one of the other wires for an actual 8V).  I have small heatsinks (5W or so)
> on the three regulators.

I'm ain't no EE, but that doesn't seem to make sense to me.  Try 
measuring the AC voltages that you are getting without the rectifier and 
see what you are getting.  With a 28VCT (also written 14-0-14) you 
should  be able to make a nice +12/-12 supply. You should account for 
variations in line voltage (believe you me, they exist!!) and have about 
2V more input into a three-terminal regulator than you want in output. I 
might have misinterpretted what you are doing, but you seem to want to 
get 15V from 14V without using any sort of voltage doubler or switching 
(DC-DC) supply -- I don't think you can do that.

> I'm using a pair of 10 ohm 10W power resistors in series to load the +15
> supply and another pair for the -15V supply to .75A each.  My DMM reads
> about .73A so I know this is close.

Why are you doing that??  Is this just for testing purposes??

> 2.  The power resistors also get very hot and actually put off an odor from
> the heat.  Is this normal?

Yes, power resistors do throw off lots of heat (that's how they work).  A 
bit of a smell is normal (especially if they are new).  

Anyhow, after you solve your other problems, you might want to look into 
adding extra caps and diodes to your regulators -- you can greatly 
improve the ripple rejection with a small increase in the number of a few 
inexpensive parts.

Sorry, if I couldn't be of more help.

PEACE OUT :)
MARK