This 1977 circuit only allows the solenoid to energize if the right combination of switch positions is selected. The relay is 6 or 12 V depending on the low voltage supply used.
This test consists of a simple Hartley oscillator using a transformer of the type found on older...
This circuit, from a 1985 documentation, produces several types of sound effects selected by the...
This 6-transistor receiver was manufactured in Japan in the 60s. The circuit is superheterodyne and has a 6V...