Marco DI LEO wrote:

> You can also find the article at the web site of Electronic Design:
>
> http://www.penton.com/ed/Pages/magpages/may1398/ifd/0513ifd.htm
>
> Ciao
>   Marco
>
> Calvin wrote:
> >
> > You can also check out page 134 of the May 13, 1998 issue of Electronic
> > Design, where is a simple design of a Rotation Counter, using no moving
> > parts, taking advantage of the momentary short created by the brush of a
> > permanent magnet motor.
> >
> > Calvin
> > TGO Electronics


Thanks to all who have replied on this topic so far.
Especially counting pulses as proposed in the Electronic Design article
seems promissing.

New suggestions are still welcome. Therefore, see below a part of my original
message:

I am interested in speed regulation of a small DC brush motor (e.g. as used in
model trains)
by using a PIC. Most information that is available refers to  applying a PWM
output signal to
a mosfet H-bridge. The H-bridge is used for direction control. The PIC
produces a PWM signal and the speed is controlled by the duty cycle of
the PWM signal.
However, does anyone have a PIC solution to the feedback control
problem: i.e. a regulated constant speed by measuring the actual motor
speed and comparing it to the desired speed.
An additional limitation is that the hardware should be very small (SMD
components) in order to fit in models.


Joost de Vlieger
mailto:de.Vlieger@net.hcc.nl