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Old May 24th 06, 01:55 AM posted to rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc
Tim Wescott
 
Posts: n/a
Default Control Unit for Home Built Rotator from Pitch-Prop Motor

Hey Kevin:

http://www.wescottdesign.com/articles/pidwophd.html
http://www.wescottdesign.com/article.../friction.html

If you want to control it from a PC I'd suggest that you drive an H
bridge from a microprocessor, with a PID controller in there to make it
go. The biggest key to making a PID loop without doing a bunch of math
is to keep your ambition under control -- if you have to go fast, then
you need to delve into theory.

As pointed out, PID control can be tricky -- even though I'm a control
systems professional there's a good chance that if I did it rev 1.0
would just use the micro to implement virtual buttons, with feedback
control for rev 1.1. You definitely want to make sure all the pieces
are working before you close the loop.

Kevin & Natalia wrote:

Hi Tim,

My electronics skills are fairly good, I have built many projects over the
time.
What I was wanting to do, is have a control box in the shack with a readout
and left/right controls. And have the provision to also be able to have a PC
control it.
I like the Pitch-prop motor, as it is strong, and can be controlled easy.

The way I control it at the moment, is via a 2 voltage system.
The pitch-prop runs at 36volts for full speed, and when I wish to slow it
down for small movements, I use a second set of controls at 15volts. Not the
best way of doing it, but it works.
I then look out the window and see where it is pointing. I know where N, E,
S, W are on my section.

As to price on the parts, I would like to keep it down to around a couple of
hundred dollars.

Regards and thanks for your input.

Kevin, ZL1KFM
www.qsl.net/zl1hk

"Tim Wescott" wrote in message
...


Excepting the readout, this should be a fairly routine motor control
problem. Depending on what you want to do your control box could be as
simple as a current-limited power supply and a couple of switches or as
complex as a fully fed-back motion control system.

How's your electronics skills, and how fancy do you want it to be?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html






--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html