This small tone generator was found in the November 1987 issue of Radio Electronics magazine. The phototransistor is common and controls the sounds generated. The basic frequency is given by C1.
This circuit is from a 1965 Motorola documentation. The transistors are of the time as is the...
This circuit was found in a 1966 General Electric book. The triac and the day are from that time...
The purpose of this circuit is to modify the sound of organs so that they resemble the sound of a...