Motor control

[Mechd07]

I'm looking for a reversable speed controller that uses variable DC input voltage (about 0-20 Volts) to control higher DC (30+ volts) or AC output voltage proportionately. Something like this must exist. If so what type of controller is it?

 

[itsmoked]

Actually it probably doesn't exist.
0-5 Volts and 0-10 Volts and 4-20mA are a lot more common.
You may need a voltage divider of some type.

 

[Mechd07]

Thanks for the reply. I think I found a better way to accomplish my goal.

What I found were speed controls (some robust enough to make a go-cart with) for robotics that use PWM signals from receivers used for radio controlled models, and something called a comparator to convert plain DC voltage to PWM signal since I don't have one readily available.

http://www.ifirobotics.com/speed-controller-selection-guide.shtml

http://www.robotmarketplace.com/marketplace_speedcontrollers.html

1) DC into comparator
2) Comparator generates PWM signal
3) PWM signal into speed controller
4) Variable and reversible DC out

Would this method work with the speed controllers mentioned above?

 

[Mechd07]

I would like to add itsmoked that I found a 'better way' than my pervious ones. I was'nt saying better than your idea. Just though I would clarify that.

 

[itsmoked]

Oh hey not a problem.

Those look like they would work to me. I didn't look close enough to see how they handled reversing tho...

 

[Mechd07]

Cool. Thanks for your help.