This sound effect circuit is from a Radio Electronics magazine from December 1969. The transistors support equivalents and the power is provided by a battery to reduce the possibility of noise.
Found in an Electronic Design from the 90's, this circuit uses an SCR according to the controlled power....
This circuit was found in an English publication from 1967. The circuit is for listening on a...
This is the traditional configuration of an OR gate using a voltage comparator, but it can also be...