The circuit presented is a Japanese commercial radio from the 1960s. With a 4.5 V supply, it is a super-heterodyne type with an IF of 455 kHz. 6 germanium transistors are used.
A ring and pendulum of stripped wires form the sensor for this alarm. Once triggered, to reset, you...
Designed for the audio track, this circuit was found in a Popular Electronics from the 90's. Other...
An interesting basic circuit for projects is shown in the figure. It consists of a digital...