This small analog TV transmitter was found in an Electronics Now from the 90s. The range is around 20 meters, and the coils are according to the channel on which you want to receive the signal.
This circuit automatically inverts the test leads connection according to the polarity of the...
With a touch of the push button the lamp is switched on. A new touch and the lamp go out, in this...
This 80's circuit uses a light-sensitive SCR or LASCR and a one-sided silicon switch SUS, uncommon...