Analog Joystick to Variable Speed/Reverse DC Motor

[dukegreen]

Hi, all. I would like to power a small low speed DC stall motor (12V max) using an analog joystick. It would be easy, I think, if the joystick were max or min at center, then variable in either direction. However, the joystick I have is 10K ohms with 5K at center rest. It lowers resistance when shifted down and the reverse when shifted up.

Does anyone have a circuit that would do this? I realize I could simply use a DPDT to switch polarity, but that would not supply variable speed. I want to keep it simple, not using Arduino, etc.

I'm not very electronically literate. I can use passive components ok, but have little experience w/ chips, transistors and the like.

Thank you
Duke

 

[dukegreen]

I see there are several views, but no replies. Is such a control scheme possible? Is there another forum that might have input?

Thanks

 

[duke37]

Hi Duke
One way would be to put the 12V across the potentiometer so that you get 6V in the central position. Add an amplifier to give sufficient motor current.

Make a voltage divider to give a 6V reference with sufficient motor currnet.

Connect the motor between the two sources. Twiddle the pot up and down.
Note that the motor will get a maximum of 6V. If you make the reference do the opposite of the pot output, then more motor voltage would be available.

I am not into model control but I would have thought that this circuit would be common.

Duke37

 

[dukegreen]

Great! That did not occur to me, but if I'm the smartest one here, we are in trouble. It likely is a common circuit, perhaps the way I worded it in a web search did not give the correct answer.

Thank you very much. I will leave some feedback on the outcome.

Duke