555 and the like

Two comments on 555 stepper drivers:

Radio shack carries an inexpensive little book on the 555.

An HP deskjet contains an L298 dual H bridge chip. It also contains
some power supply components that might be useable for stepper drive.
Of course unless one wants to buy an L297 chopper step->phase chip
power resistors will be necessary to make an L/R drive.

And for those contemplating servo projects the deskjet has a small DC
motor (I keep meaning to test it as a tach) with 500-something line
encoder and HEDS reader module...

Watch your neighbours trash piles...

Chris

--
Christopher C. Stratton, stratton@...
Instrument Maker, Horn Player & Engineer
22 Adrian Street, Somerville, MA 02143
http://www.mdc.net/~stratton
NEW PHONE NUMBER: (617) 628-1062 home, 253-2606 MIT