The circuit shown in the figure below is from the 1993 Linear Technology Applications. The operational ones used are uncommon and the use of equivalents can be analyzed.
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...