The transistor can be a BC548 and the coil has the following characteristics for 1 MHz. L1 has 80 turns of wire 28 in a ferrite rod and L2 of 30 and 40 turns.
Based on an operational of the time, this Popular Electronics circuit can be designed with any...
In the circuit shown in the figure, when the input voltage rises to 27 V, the TL431 triggers the...
This circuit indicates whether a cable or wire is energized by simply approaching its antenna. The...