This very low frequency amplifier has a gain of 1,000 and was found in a 1967 documentation. The circuit is suitable for detecting explosions, distant echoes and seismic vibrations.
This loop antenna was found in a 1990s documentation. The circuit includes a field strength meter. The...
This circuit is from the LM317's own manual obtained from an old documentation. The IC should be...
In the figure we have the conventional configuration to use a triac to control a power load from...