This circuit using programmable unijunction transistors was found in General Electric documentation from 1964. LEDs can be used instead of lamps.
For the 600 kHz range coil is formed by 35 turns of 28 AWG wire on a ferrite core with a diameter...
Found in a 1970’s documentation, this circuit uses components of the time, uncommon today. |...
This 2003 circuit uses two types of sensors: by reed-switch and by infrared. If the magnetic...