Re: [CAD_CAM_EDM_DRO] Digest Number 636

-cut-
This sounds like an excellent solution for those of us who don't
have the "better half's" financial support!! HEHE Do you have a
circuit diagram for the controller/driver you are using? I have
built
a driver using L298's and it works beautifully but the operating
voltage of the syn. motors is way too high for the 298's. Does
anyone
know if I could use solid state relays controlled by the 298's?
Would
the relays be fast enough to react to the step commands?
-comment-
Don't use a relay

Try using a NJR 3776 chip.- previously the pbl3776 This is used by several stepper board driver makers.
You can drive FET's to10 amps with it at 40 volts
When you parrallel the coils in the large slo-syn motors, you drop the voltage needed from 120 rms to 30volts.
The 3776 would prefer much more for fast chopping but you can run them up to the rated 72 rpm at 40 volts.

.Another chip is the LMD18245 from National Semiconductor.
It drives 3 amps at 55 volts as a full wave pulse modulated bridge.

The hip 4080 chip appears to be able to drive a nFET bridge to 80 volts. Newark lists the chips at about $7.50 each
It has good drive to the gates of the nFets.

The uc3517 can be used to select the input pulses on most of the H bridges.

The easiest is to buy a kit from the list contributors.

Cheers
Tex