This converter that allows high voltages to be obtained from batteries was found in Radio Electronics magazine from June 1959. The circuit uses a special transformer providing 9 to 18W of output.
This amplifier with differential input uses two old op amps but can be implemented with modern op amps....
The main feature of this circuit is that it provides a sine waveform signal. In this circuit, the...
The HA2620 integrated circuit used in this comparator is from the 80's, but the setting can be...