This wired intercom circuit was found in an English publication from the 80's. The integrated circuit can be replaced by an equivalent, just like the transistor which is a general-purpose type.
Obtained from a 1967 documentation, this circuit uses transistors from the time. The galvanometer can be a...
Motors up to 2 A can be controlled by this circuit, which requires a symmetrical source. Although...
This sensitive MW receiver was found in a publication of year 1958., The circuit uses germanium...