[sdiy] Two more questions
sbernardi at attbi.com
sbernardi at attbi.com
Tue Aug 6 21:51:30 CEST 2002
Here's a 78xx, 79xx regulator based design:
Also take a look on eBay - they often have linear triple
supplies (don't buy switchers) for cheap.
As for PCB's, a lot of people have different preferences
for what they like to do. Certainly if you were going
to go in quantity, I would have them done
professionally. In all the synth building I've done,
however, I don't believe I have more than two of one
kind of board (well, maybe some VCA's). I'm always
trying new designs. At about $66 for two boards
(cheapest rate I've seen), that is more than I like to
pay. So I make my own. Now my boards aren't very
complicated, (not like the gargantuan PCB's that Jim
Patchell designs), and I used fairly wide traces (30
I use the photo-etch process. Print the pattern on
transparency with a laser printer with fresh toner (con:
sometimes I still need to touch it up with a marker). I
buy presensitized PCB's from Circuit Specialists
http://www.web-tronics.com/, which I expose with a
flourescent light for about 10 minutes a side. I etch
them in a etchant tank with Ammonium Persulfate (both of
which I also got from Circuit Specialists). Then I use
Tinit to plate the traces. Then drill, drill, drill.
It is a lot of extra work. I guess I'm weird - it's one
of the parts of synth building that I enjoy doing.
> I've got a couple more questions :)
> First, I'm having trouble finding a schematic for either a 15 volt bipolar power
> supply, and/or a +5 volt, does anybody know of a good design they could point me
> My other question is; when you are finished a design and are putting it on a
> pcb, do you use vero, etching, or photo-etching? (sorry if those aren't the
> proper names).
> I made a circuit a long time ago from an old magazine, I used a permanent marker
> on copper and then etched it, but I don't have a steady hand and it was sloppy,
> some parts were thin, some were thick, etc. The etching where you use light
> sensitive chemicals seems to be way too much work but maybe it's easier than it
> sounds. I've also seen rub-on decals which I'm guessing are used instead of a
> Vero board looks like it could get sloppy in inexperienced hands.
> So I'm just wondering, is this a matter of preference, or is there really only
> one good way to do it?
> > Steve Begin
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