This NEC commercial amplifier was manufactured in Japan in the 1960s. The circuit uses 4 transistors from the time and was powered by a 9 V battery voltage formed by large batteries.
This circuit is from American documentation from 1973. It can be used to indicate when the logic...
This circuit is from an old documentation. However, it can be mounted with modern equivalent...
This interesting circuit, found in an old American publication, measures alternating signals in a...