The transistor used in this circuit is uncommon today. AC124 or equivalent such as AC188K and 2N2431 can be used. The circuit is from the 80's and makes use of transformers.
This circuit is from an American publication of 1978. It can be assembled with modern transistors, since...
The electrostimulator or electronic massager consists of a circuit that produces high voltage...
This circuit can send signals in both the VHF and FMN bands with a range of a few tens of meters. The...