Re: [CAD_CAM_EDM_DRO] Message #23413 Re:DeskNC - CNC Pro 3x as fast as EMC???

> Larry,
> What added cost is there to program the PIC? It
> is obvious you have mastered PICs! A person going
>with your suggestion now has to add more to his
>plate.

But you were advocating just a few messages ago to do it yourself to learn
something!

If you build your own programmer, very little additional cost other than
time. Most 'non programmer' types can program in Basic rather quickly. Basic
PIC compilers are cheap. If you want to learn assembly language
programming, then it can all be practically free. You can also pick up the
Microchip or Advanced Transdata 16F877 in circuit debugger / programmer (
ICD ) for around $150. Or you can build that yourself too using the plans
from www.epemag.com

> I say build a simple controller capable of 6amps at
> 60 volts per phase. The circuit has been around for 30 years!
> It uses cheap chips and almost all Radio Shack parts. >Where can
> you find such a diagram, you ask? Well look I have a >website TOO!

The problems I see with your circuit is: (1) It's a Unipolar drive which
costs a lot of torque the motor could otherwise produce. (2). It uses
discrete logic ( flip flops and xor gates ) all of which are built into the
L297 so why build it out of discrete logic? (3). It is an LR drive which
means lots of power wasted as heat. (4). It has no current feedback so you
can't drive the motors at optimum settings as a chopper drive can.

By the time a novice electronics technician could build your circuit, they
could put an L297 / L298 board together and have a better performing
circuit.

later,
Larry E.