The 28BYJ-48 motor is a 4-phase, 8-beat motor, geared down by a factor of 68. One bipolar winding is on motor pins 1 & 3 and the other on motor pins 2 & 4. The ULN2003 driver board features four mounting holes and 4 status lights (one for each phase).
The ULN2003 contains seven darlington transistor drivers (only four are used) and is somewhat like having seven TIP120 transistors all in one package. The ULN2003A can pass up to 500 mA per channel. It also contains internal clamp diodes to dissipate voltage spikes when driving inductive loads.
To control the stepper, apply voltage to each of the coils in a specific sequence.
Rated voltage: 5V DC
Current draw : 92mA
Number of phase: 5 line 4 phase
Speed variation ratio: 1/64
Stride angle: 5.625° /64
DC resistance: 50Ω±7% (25℃)
Idle In-traction frequency : > 600Hz
Idle Out-traction frequency : > 1000Hz
In-traction torque: >34.3mN.m(120Hz)
Self-positioning torque: >34.3mN.m
Friction torque: 600-1200 gf.cm
Pull in torque: 300 gf.cm
Insulated resistance: >10MΩ (500V)
Insulated electricity power: 600VAC/1mA/1s
Noise: <35dB (120Hz,No load,10cm) Diameter : 28mm Board dimensions: 35mm x 28mm
1 x 28BYJ-48 stepper motor
1 x ULN2003 driver board