Hi All,

I have had a bit of time to think about where I am going with this project and what my ultimate goal is.
As stated in my original message

The end use for this project is to re-power my 9x20 lathe using a treadmill motor (180Vdc 2HP).
I could spend time tweaking the current system, change the PIC (along with the extended learing curve associated with the new settings) but is it really worth it? At this stage I have proved the concept using the 24Vdc motor; proved it well enough to move forward to the final platform. I have decided to take the plunge and jump straight to the full blown design. Yeah, scary huh!

The final system will require forward and reverse motor operation. This will be achieved using four IGBT's configured in an H-Bridge arrangement. The IGBT's will be fired by dedicated high-side and low-side gate drivers. All control circuitry will be isolated from the power circuit by opto-isolators (5kV isolation). Forward, reverse and stop (emergency) functions will be performed by switches on digital I/O lines, speed to be set by ADCin via a pot, feedback via photo-interrupter/shaft encoder wheel with an interrupt driven counter (eg. TMR0 and TMR1). As in the prototype system, gain terms will be set via individual pots with ADCin routines. Settings to be displayed on a serial LCD.

I have searched the Microchip website for an appropriate device and decided on the 18F2431. Quite a powerful device with lots of in-built functions dedicated to motor drive applications.

I now have lots of new information to try and get my head around. The 18F2431 datasheet is mammoth! I plan to piece the circuit diagram together, lay out a new pcb and then begin to learn the ways of driving the 18F2431. This won't happen overnight - but it will happen

Thanks to all those who have helped me get to this stage. I am sure I will be calling on you again in the very near future.

Any recommendations, suggestions or comments on what I am trying to do, before I embark on this adventure, would be greatly appreciated.

Cheers
Barry
VK2XBP