Re: Advice on moving forward

PK,

E-mail me your circuit diagram. I will look at it and come up with
some suggestions.

Mariss


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "paulk6158" <paulk@i...>
wrote:

> Hi folks, I've spend some bleary hours tolling the archives (LOTS

of

> good stuff there) but haven't found a directly applicable post so,

if

> I may ask.
>
> I've spent about 3 months tinkering with stepper drivers designs
> based on pic micro's. With acceptable results.
> Recently I bought a larger (400oz) motor rated at 3V 4A.
> I just can't seem to get this thing to work at more than 150PPS!
> At 100PPS it's fine. Really good torque, no problems.
>
> The current setup is a 24V supply into a micro controlled PWM
> constant current regulator into a simple, wave drive, controller

with

> darlington output drivers. Whilst I haven't borrowed the DSO from
> work and watched the current across the (unipolar) coils, there is
> 6600uF on the output of the PWM unit, the DC voltage across the

sense

> resistor seems rock solid and none of the transistors get more than
> warm.
>
> The datasheet for this motor shows a fairly flat torque curve up to
> around 1000PPS. Can anyone advise me on where I should start

looking

> for clues?
>
>
> Many thanks
>
> PK