Found in a Popular Electronics from the 90s, this circuit can be used as an electrifier. T1 can be an old TV fly back transformer or an ignition coil.
This microtransmitter operates at a frequency between 3.5 MHz and 10 MHz determined by the...
This very low frequency circuit was found in a 1964 Electronic Design. Transistors may be modern...
The sensors of this liquid alarm are formed by two pieces of wire with the ends peeled off. The...