The scope of this paper relates to the development of a novel microprocessorbased tachometer using an innovativemethod, here referred to as the 'rampwaveform sampling technique', to provide high accuracy and fast dynamic response while maintaining relative simplicity both
in terms of the basic electronics and the computational algorithm. The ramp waveform is generated electronically by means of the 'analogue integration' of the time difference between consecutive encoder pulses. This is achieved using a temperature compensated linear ramp
generator which employs a transistor switch, turning on-off at the falling and
rising edges of the train of square pulses from the sensor, and a constant current
source to charge a capacitor.