We control easily a motor to stop and rotate. If need to control it on linear feature is speed high-low difference so use this circuit.
In Figure below, we use the 4 bit comparator circuit that output to the input of EXCLUSIVE-OR gate. Then, it is fed to the voltage divider circuit. Which is final output voltage that changes as the level of bit input, that maybe come from the counter circuit or the keyboard decode circuit.
The output of the comparator circuit (A>B, A=B, A
This circuit also can apply to Rotating antenna on the remote or the VCO circuit that does not phase noise.