This circuit was found in the August 1994 issue of Electronics Now magazine. The 4046 is uncommon these days and the frequency range is given by C1.
This configuration, which uses a transistorized circuit in the feedback, provides a logarithmic response...
This receiver uses one of the first transistor types available on the market, the CK722, but it...
Suggested by General Electric in 1967 this circuit generates a single pulse when receiving a light signal...