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 uses a LM3900 Norton amplifier and a 2.7 V zener diode to supply a current of 1 mA to...
This simple circuit turns on a small lamp (or LED) when the light stops shining on the sensor for...
The LM123 series (223 and 333) is manufactured by several semiconductor companies. The circuit below...