^Hi,

Shahid Sheikh wrote:
>
> Yep. Dont tell me you've quit :)

How could I ....

Did you heard of the Danish Guys who made a Motorola-Protocol
decoder for maerklin based on a PIC 16C84 ?

http://hjem.get2net.dk/formula.micro/indexeng.html

>
> 19.somthing is the max I can generate with the Atmel chip I'm planning on
> using so I think that will work.

AFAIK the higher the better but also 12 KHz may be ok, I think 20 KHz
is just choosed because of being outside the audible range.

The high frequency pwm versus iron-core motors is necessary because
the coreless motor has just a cooper-network glued tho the shaft.
the forces acting on this network will be smaller if more short
pulses of power are applied than only some long.

>
> Anyone knows the benefits of using coreless over a iron core motor (or did I
> already ask that)?

one main difference is the mass of the rotor (inertia). also coreless
motors
has virtually no "Rastmoment" - means if you just take both kind of
motors,
and try to turn them manually you will notice that there is some "force"
necssary
to turn the iron core motore whereas much less "force" is necessary to
turn the
coreless motor.

- oh, I forgot the real difference: Price. :-)

>
> Also I was wondering how pronounced is the back emf of a coreless motor Vs.
> a iron core motor. It should be better than an iron core motor right?

I'm sorry, but this need to be answered by someon else - never tested
this.

Kind regards,

        Stefan