This long interval timer was found in the September 1976 issue of Radio Electronics magazine. The output can be used to control a relay. The circuit achieves timings of up to 14 hours.
In the figure we have a way of using a solar cell as a source for circuits with tunnel diodes. The solar...
This equalizer was found in the May 1978 issue of Radio Electronics magazine. The component values...
This circuit for high-impedance magnetic headphones was suggested as an experimental amplifier for hearing...