Stepper motor (unipolar) (ULN2003)
28BYJ-48 geared stepper · 5 V · four 50 Ω phases with a common (red) · 4096 half-steps per output turn (64:1 gearbox) · tops out near 15 RPM: step faster and it stalls · drive the phases low in order with a ULN2003
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Typical part: 28BYJ-48 5 V geared stepper
Pins
- Red (+ common)
- Orange (A)
- Yellow (B)
- Pink (A̅)
- Blue (B̅)
Ratings and limits
| Coil | 50 Ω per phase |
|---|---|
| Steps | 4096 half-steps per output turn |
| Speed | ≈ 10–15 RPM max |
| Torque | ≈ 34 mN·m |
How to use it
Drive with a ULN2003 board: pull the phases low in the order Orange, Yellow, Pink, Blue (half-step: one, then two together). Too fast and it buzzes without turning.