7.8Amp Driver Pack

Created by: Lester Caine, Last modification: 20 Jan 2009 (14:14 UTC)

The external driver pack is based around the 7.8Amp module from Arc Euro Trade. This provides sufficient drive for the 680Ncm motor and runs directly off the output of the DivisionMaster.
Datasheet on driver 7ADriverData

Pin Signal Wire Notes
4 Step Grey  
5 +5V Red Link all 3
7 0V Black Can be left floating
8 Enable Pink  
9 Direction Violet  

The Enable output is active when the LED is lit on DivisionMaster, otherwise the the motor is disabled. If it is necessary to maintain power to the motor for holding purposes, then use pin 7 rather than pin 8, and the motor will only be switched off when DivisionMaster is switched off.


The colour coding for the motor connections has been modified so that it matches the motor cable, something that will be followed through to the DivisionMaster itself at some point.

Power supply is a transformer and bridge rectifier arrangement providing around 70V to the driver module. This leaves a large margin of headroom to the 90V maximum.

Overall size of driver - 155mm x 205mm x 130mm high exclusding connectors.

Component List

  1. 7.8A Bi-Polar Stepper Motor Driver
  2. 500VA 50V Toroidal Transformer
  3. 200V 35A Bridge Rectifier
  4. 3300uF 100V Electrolytic Capacitor
  5. Switched IEC mains inlet
  6. Low voltage power harness
  7. Aluminium Case (205mm x 155mm x 75mm )

To Do ... Circuit Diagram, Case machining drawings