Electrical synthesis of mechanical bell

Claim 1

A circuit for the electrical synthesis of a mechanical bell sound and comprising in combination: (a) a rate clock for providing signals at a predetermined stroke repetition rate; (b) a first exponential decay circuit coupled to said rate clock for producing a first decaying exponential control signal having a first predetermined time constant; (c) a second exponential decay circuit coupled to said rate clock for producing a second decaying exponential control signal having a second predetermined time constant; (d) first, second and third oscillators for producing signals of first, second and third frequencies, respectively, which comprise the low, intermediate and high frequencies, respectively, of the three most significant frequencies, other than that of the stroke repetition rate, of the mechanical bell to be synthesized; (e) a first modulator adapted to produce a first output signal which is a function of two input signals and with said first control signal coupled to said modulator as one of the inputs thereto; (f) a second modulator adapted to produce a second output signal which is a function of two input signals with said second control signal coupled to said second modulator as one of the inputs thereto; (g) means for coupling said first, second and third frequencies to said first modulator as a second input thereto; (h) means for coupling said third frequency to said second modulator as a second input thereto; (i) means for coupling the output of said first modulator to suitable audio means; and (j) means for coupling the output of said second modulator to said suitable audio means.