Clearly this is a newbie question, but I'm a bit confused if one would need a motor controller or just some relays in an hbridge configuration (see previous post) to turn on and off some DC motors.
These particular motors are already controlled by existing momentary switches I was planning on tapping into the existing power and simply switching it via a couple of relays. Basically, I'm just going to "impersonate" the manual switches.
I have assumed I don't need a motor controller - I suppose these are required when you wan to drive the current through the board rather than switch external current, correct? Also, they might be used to deliver higher current PWM etc.
Well the main advantage of using a H-drive instead of relays is that it would allow for variable speed of the motor via PWM signal from the Arduino, you can't control motor speed with relays. If you just need to run the motor full speed in either direction then relays can work. Often relays will require more space and consume a little more power then a H-drive but that is pretty much project related.
The motors I'm controlling currently move only at one speed, which is slow - I assume through their gearing. I was thinking to put a couple of relays together to create an H bridge to run them in forward and reverse. But the real question is if I need a motor controller, or just a network of switches. But, ... I guess I should make sure that the existing circuit is not slowing them down through PWM and i would just rip them at top speed
retrolefty:
Well the main advantage of using a H-drive instead of relays is that it would allow for variable speed of the motor via PWM signal from the Arduino, you can't control motor speed with relays. If you just need to run the motor full speed in either direction then relays can work. Often relays will require more space and consume a little more power then a H-drive but that is pretty much project related.
There is of course a "hybrid" option of using a DPDT relay with contacts of suitable current rating for the load needed to switch the direction of the motor, while using an NPN or N-Channel mosfet (again, of suitable rating) between the relay and ground to do PWM for speed control. Not the best solution, but perhaps simpler than a full-on non-relay h-bridge to design and build; the biggest problem with such a design is that you couldn't switch direction of the motor as quickly...
Well, I think I'll just try to put 12 volts to those motors under controlled circumstances and see what they do. I appreciate the guidance, I'm sure I'll ask for more later
