stepped voltage generator

elektor july/august 1983 stepped- voltage generator This circuit converts an input signal into one that is composed of a num- ber of discrete steps but which re- mains otherwise identical to the input signal. Because the steps are of equal height, the harmonic con- tent of the output signal will be dependent upon the amplitude of the input signal. This chararac- teristic is extremely useful in the making of electronic music. The circuit uses quantitised pulse- width modulation for the adding of the step-shaped input signal. Pulse-width modulation is obtained by comparing a triangular voltage with the analogue input signal by means of a comparator; the quan- titising, that is the adding of the steps, takes place by replacing the triangular voltage with a stepped voltage. The stepped-voltage generator con- sists of three gates, Nl ... N3 and transistor Ti. Nl operates as an astable multivibrator, that oscillates at a frequency depending on the value of Cl and R 1. Transistor stage T...