DW870-DC Stepper Motor Driver Open Loop
Two-phase stepper drive, 18-80 V, output current dip-switch selectable from 1.4 A to 7.0 A.
Overview
The DW870-DC is a two-phase stepper drive covering the same 18-80 V supply range as Tiny Controls' own Tstep-087, with output current set by dip switch rather than a jumper.
Current runs from 1.4 A to 7.0 A, which covers NEMA 23 and most NEMA 34 motors. Dip switches stay visible and are easier to re-set than jumpers when a machine's motor selection is still being finalised during commissioning, though the Tstep-087 reaches a slightly lower current floor of 1.2 A for smaller motors.
Microstepping, idle current reduction and short-circuit protection are all included as standard. STEP and DIR inputs are optically isolated, which keeps the controller's ground out of the motor power loop and stops a noisy supply from injecting false steps.
If the application needs bus control instead of pulses, the Tstep-087-485 in the same voltage class runs from RS-485 commands.
Supplied by Tiny Controls in India.
Specifications
| Rated Voltage | 18-80 V |
|---|---|
| Rated Current | 1.4 - 7.0 A |
| Microstepping | YES |
| Current setting | DIP switch selectable |
| Idle Current Reduction | YES |
| Short Circuit Protection | YES |
| STEP / DIR inputs | High Speed Optically Isolated |
Questions
Why DIP switches for current setting instead of jumpers — does it actually matter?
Mostly a commissioning convenience — DIP switches stay visible and are easier to re-set than jumpers when a machine's motor selection is still being finalised.
Will this cover both NEMA 23 and NEMA 34 motors?
Yes — 1.4 A to 7.0 A covers NEMA 23 and most NEMA 34 motors.
How does this compare to your own Tstep-087?
Same 18-80V supply range, but the Tstep-087 reaches a slightly lower current floor (1.2A) for smaller motors, and sets current by jumper rather than DIP switch.
Why are the STEP and DIR inputs optically isolated?
It keeps the controller's ground out of the motor power loop, which stops a noisy supply from injecting false steps.