I'm working on a project using a micro to control two industrial servo drives. These drives take analog inputs of -10 to +10v. My plan is to use a dual-rail opamp circuit that takes a pwm input from the micro (0-5v) and outputs -10 to 10v. My question for the community is about how to provide the dual-rail supply to the opamp. I believe I could theoretically get, say a 24v supply, use resistor divider circuit to set 12v as ref point/gnd and then get +12 and -12v at 24 and 0v, respectively. However, I am concerned about this method when there is more going on. It is my understanding that with this method I would have to:
- supply power to my 5v micro using 17v and ground it at 12v
- supply all power demands to the servo drive with this offset and do the same for its grounds
If these assumptions are correct, then I do not think this method will work. I have a bunch of additional inputs and outputs that require power that might make this complicated (but maybe not--I would be happy if someone could convince me otherwise). I have been looking for dual rail supplies to purchase, but haven't had much luck. I also considered using a pc power supply unit, but the current ratings on the -12v line seem too low. I would appreciate any guidance on where to move from here!