This alarm circuit was found in April 1975 Radio Electronics magazine. The circuit uses a 12 V power supply and relay but can be modified to work with other voltages.
Found in Linear Technology documentation from the 90s, this circuit uses components from that...
This 500 MHz oscillator has an output power of 1 W when powered by a 20 V source. The circuit was...
This circuit is from 1987 when there were only analog TVs and stereo sound was still a novelty for this...