The DSC4020 bipolar chopper drive is designed for development projects — just connect a single power supply and motor and the drive is ready to run. An onboard potentiometer sets motor current; no external resistors are required. The drive provides all basic motor controls including full or half-stepping of bipolar steppers, directional control, and output-enable control. An oscillator circuit is standard, as is an onboard speed-control potentiometer.

Haydon Switch & Instrument Inc., 1500 Meriden Rd., Waterbury, CT 06705, (800) 243-2715,