This circuit is from a 1967 US publication. The configuration can serve as a basis for designs with modern components.
This circuit is from a 1980s documentation, but the configuration can be applied to most modern...
This 0.5 Hz filter was found in the December 1990 issue of Radio Electronics magazine. The power...
This circuit was found in a 1977 Radio Shack documentation. The circuit is TTL, which must be...