MEDW 55V 3A Stepper Driver - Interfacing

Created by: Lester Caine, Last modification: Sat 27 of Mar, 2010 (20:33 UTC)

Installation of the driver is relatively simple, just requiring a 4 wire molex link from the MEDW0010 breakout board, and a four wire connection to the stepper motor.

3ADriver Assembly The board will run up to 55V, and a suitable raw supply can be provided by using a 35V transformer. With a suitable bridge rectifier and capacitor this will provide around 51V DC which provides a little head room on the 55V capability of the chip set.

3ADriver Control Molex cable from the MEDW0010 board pickes up the step and direction signals, and the driver 'Enable' signal.

3ADriver Output Our standard method of connecting to stepper motors is via a 4 pin XLR style connector which provides a rating of 6 Amps which is more than adaquate for most of the smaller motors. The ferrite core offers sufficient EMC screening when used with a screen cable to the motor itself. See the motor assembly details for more information on that. Note that the colour codding on the connection to the board matches that on the cable.

3ADriver Links There are only two settings required on the board. Links are provided to select the current ratting, with a pair of links needing to match the current required. This section of the board could be left unpopulated, just fitting a pair of resistors for the current required, and intermediate values can then be calculated if needs be.
The board is designed to provide 4 micro stepping rates. Single stepping, Half, quarter and eigth stepping. Any more than that is really false economy as only the full steps from the motor are acurate, and the motor will drop back to the nearest full step when power is removed. ( Must work out which link settings match which step size! )

Price list for the driver can be found here