Wiring connections for the Minebea Astrosyn 28BB-H151-11 and the high stepping automatic coil winder driver board.
The stepper motor above is configured as a unipolar motor. The red and black leads of all 4 phases (coils) are tied to +5 volts.
The other lead of each of the phases is tied to a mosfet on the circuit board. As each mosfet on the board is energized it pulls the corresponding motor lead to ground potential and powers that phase of the stepper motor.
|Wave Drive (Clockwise)
|Full Step Drive (Clockwise)
The step switching sequence tables above correspond to the 28BB-H151 stepper motor drawing to the right configured as a unipolar stepper motor. Direction of rotation viewed from shaft end. Wave Drive full step one phase energized and Full Step two phase energized.
When I originally tested the AD8048 power adapter with the coil winder it seemed to work okay as I was mostly running the winder in wave mode (single winding energized) and it also seemed to handle full step mode (two windings energized).
But since running the winder with my PIC based controller and running the winder in full step mode I had found that the power adapter cannot handle the load, and for the time being I have paralleled another 5 volt 3 amp power adapter with the AD8048.
Although I had tried to go the route of using a small switching supply power adapter I have since come to the conclusion that a computer power supply with the needed modifications would be the most cost effective and versatile method to power the winder.
The 28BB-H151-11 stepper motor is a 4 phase (8 wire) permanent magnet unipolar motor, but it can be configured for unipolar or bipolar use.
The approximate dimensions of the Minebea 28BB-H151-11 in inches are:
- Diameter 2 11/16"
- Mounting plate 2 3/4" square
- Motor depth 1 5/8" (excl. shaft)
- Mounting holes 2 9/32" on center
- Shaft 3/4" long
- Shaft diameter 1/4"
- Motor weight 664 grams
Inside view of a Minebea Astrosyn 28BB-H151-11 stepper motor.