Stepper motor driver for telescope mount
I have tried many different drivers for my mount but none seem to work except the Ramsey SMD1 which uses a MC3479 chip which is no longer available. I use a clock line and a directional signal (logic 1 or 0). frequency of clock line ranges from 8 to 130 Hz. I have downloaded several schematics which don't work to well. they all use dual H Bridges in the output stage. One works to some extent . It runs for several seconds then stops pulsing and runs at full speed. I am using two motors from an Arduino robot instead of one stepper.
The last picture is of my rendition of the original circuit.