Re: PS

Soneone wrote me offlist about the power supply I built with you guys' help.
I wrote them back with the below reply, and then thought there
might be another person here that could use this stuff to help them as well.

If it helps, use it.
If you already know this stuff, check me for errors, or just ignore it.

Weyland
---------------------------------------------------------------------------

If I can help someone else (if only a little) I'll do my best.

I listened to the teachings of the "Elders" on the list.
Out of this, I figured out what I needed.

A transformer, a rectifier, and a capacitor for the most basic of pwr
supplies.
I calculated the power requirements of my motors.
Again, with the help of the list members.

I looked and looked and looked, and finally stumbled across this -

http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1640317167&r=0&t=0&sh
owTutorial=0&ed=1001529657&indexURL=0&rd=1

Now, taking a guess, I figured any transformer that took
480 and made it 240 or 240 and made it 120 and vice-versa
would take 120 and make it 60 (approximately).

(Knowing that no outlet puts out exactly 120 meant
it would probably be closer to an end result of 55 VAC.)

Now, I learned that if you use a bridge rectifier
you *gain* voltage by a factor of 1.4.

So, that means that if I have 55 VAC and
run it through a bridge rectifier, I get 77 VDC.
(55 multiplied by 1.4 = 77)

The capacitor is used to "smooth" out the current.
Capacitors "store" electricity and then discharge it in one big burst.
By using a capacitor "in-line" you always have a ready supply of voltage
available.

Now, I have added some other parts to the mix.
This brings up a good point I want to share.
*Go* to your local electronics stores and hobbyists.
Talk to them.
*Most* are alllllllllllllllllll too willing to bring someone new into their
madness.
I got tons of advice which corresponded nicely to what I was told on the
list.
It's always nice to have someone confirm things for you in person.

I was given the rectifier (actually 4).
The capacitor cost something like $15.
I was shown how to put a transistor and resistor in the circuit to help
regulate the circuit after I asked about using a zener diode in there.

I asked about the zener diode after someone mentioned to me that
I should make every effort to insure that the voltage *never* goes above 80
VDC.
I had a flashback to my high school years electronics class and actually
remembered something about them not letting voltage above their rating pass
by.

I'm still not too clear on the actual workings
of the transistor, but I know my circuit works~!

The guys also recommended I put another capacitor in the circuit, so I did.
I don't know how to draw those ASCII character schematics the guys on the
list do, so I can't draw it right now, but I'll try and uncover the scanner
and send it to you if you need it.
My guess is that your local shop will recognize what I'm telling you
and whip it out of his head like my guys did.

I bought a small breadboard from Radio Shack, a header for the wires
to enter and exit off of the board, the resistor, the transistor, and the
diode.
Assembled it all on the board, and soldered.

VIOLA~!
70VDC.

Lemme know if you need more details,

Weyland