Hello people I have got the task of building a show engine for the new Rolls-Royce Phantom. The engine is motorised and is going to be powered with a 220v single phase 50Hz supply. The motor will have a rating of about 3kW. I would like to vary the speed of the motor using the cars throttle pedal. The pedal uses a hall sensor (i think this is the same as a variable resistor but with no physical electrical contact. The pedal is supplied with 5v and has an output of between 750mv and 4500mv. Can anybody help me design a circuit to control this motor?