Attack and sustain switching circuit for an electronic musical instrument

Claim 1

An ''''attack'''' switching circuit to be employed in an electronic musical instrument for obtaining ''''attack'''' signals and ''''sustain'''' signals simultaneously, said switching circuit comprising: a transistor the input circuit of which is connected with a tone signal source, said transistor being further biased so that it is brought into a nonconductive state at the time the switching device is opened; a switching device connected in the emitter circuit of said transistor; an electromagnet also connected in the emitter circuit of said transistor; an electromagnet also connected in the emitter circuit of said transistor in series with said switching device; a capacitor also connected in the emitter circuit in parallel with said switching device and said electromagnet, said capacitor being charged when said switching device is opened and discharged through said electromagnet and said switching device when the switching device is closed; and a magnetosensitive element located near said electromagnet and connected through a high resistance across the collector circuit and the ground, whereby the ''''sustain'''' signals are obtained from the collector of the transistor and ''''attack'''' signals are obtained simultaneously from the junction between the magnetosensitive element and the high resistance.