Hi Martin,

What an excellent discussion! PWMing a DC motor is one of those things (at
least,in my newbie level of experience with it) which at first seems
trivial,but you quickly reealize that there are many design choices to make
(e.g.: what PWM frequency do I use? How much power will my switching
elements need to dissipate? What voltage should I use? What overcurrent
protection scheme? How do I prevent overheating of the driver transistors
due to low thermal time constant of the die?,etc.)

I came up against all of this for the first time when I designed a small
wall-following robot for an app note written for Wirz Electronics. Luckily,
Ben Wirz was able to share his wisdom about motor driver protection with
me,and I got the general hang of it after doing a few simulations using a
program I whipped up in QBASIC (somebody on this list once called QBASIC
the best all-purpose math analysis package - I agree!!).

I will be re-reading your explanation several times to get the full value
of it.

Sean



At 03:05 PM 9/4/99 +0200, you wrote:
>Oops, I accidentally mailed my message with the title
>   "Re: PICLIST Digest - 2 Sep 1999 to 3 Sep 1999 "
>instead of
>   "Re: Driving a high voltage H-bridge from a PIC"
>Sorry! In order to save bandwidth I won't remail it
>with the right title.
>
> -- Martin Nilsson
>
|
| Sean Breheny
| Amateur Radio Callsign: KA3YXM
| Electrical Engineering Student
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