High Current Motor Driver Schematic required

[praveen_khm]

Hi,

I have checked around for any opensource schematic for controlling high power DC Brushed motors, but it looks like I was not able to find any. I need to design something similar to http://www.dimensionengineering.com/products/sabertooth2x12 from dimensionengineering. Can somebody help me with links for any opensource design schematics? Even if not, any suggestions to design one can be helpful.

Thanks,
Praveen

[LukeW]

Do you need servo feedback or are you happy with just open-loop control?

[Kremmen]

Hi,

I have checked around for any opensource schematic for controlling high power DC Brushed motors, but it looks like I was not able to find any. I need to design something similar to http://www.dimensionengineering.com/products/sabertooth2x12 from dimensionengineering. Can somebody help me with links for any opensource design schematics? Even if not, any suggestions to design one can be helpful.

Thanks,
Praveen

Familiarize yourself with the functionality of the L297 / L298 stepper driver ICs. They won't do exactly what you need but once you understand what the chips contain and how they work, it will be easy to re-implement the relevant part of the functionality to drive a DC motor. Essentially it is a H-bridge with PWM current control scheme. On top of that you still need an armature voltage control circuit with its own feedback, either from a simple tachogenerator or a pulse encoder, depending on what kind of speed controller you want to have.

[awallin]

Can somebody help me with links for any opensource design schematics? Even if not, any suggestions to design one can be helpful.

H-bride designs:
http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Bridges_-_Half%2C_Full%2C_Three_Phase
linuxcnc on real-time linux can close the loop in software. (fpga-card to read encoder and output pwm required for good performance. hobby-level performance might be doable over parallel-port)
or here's a very simple one: http://emergent.unpythonic.net/projects/01142347802

and one with a DSPic to close the loop:
http://members.shaw.ca/swstuff/dspic-servo.html