This powerful high-fidelity amplifier was described in an article in Radio Electronics magazine in December 1973. Note the use of 8 high-power transistors that must be mounted on excellent heat sinks.
This circuit with only one transistor was found in Japanese documentation from the 1960s. The...
This resistance meter was found in an English documentation from 1989. The operational amplifier admits...
This CMOS oscillator circuit generates signals up to a few megahertz, depending on the capacitor value....