Re: Motor speed control via back-EMF detection

Philip Pemberton wrote:
Tim Wescott wrote:
The only trick is making the negative output impedance match the armature impedance of the motor. I'm sure that there's a bit of tweaking involved in getting the figure right, and in compensating the amplifier so it's stable when you hang a motor off of it, but it's been done for years.

True.

With the aid of a cheap laser diode, a phototransistor and an oscilloscope, I've measured the motor speed to be around 3000RPM (+/- about 100RPM as the motor load changes). Now I just need to track down a MOSFET and a microcontroller of some description, and rig up some form of speed controller.


With a Mabuchi consumer grade motor? Wow. That sounds like Beluga caviar on a slice of Wonderbread ;-)

--
Regards, Joerg

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