This circuit uses a resonant reed switch at the trigger frequency. The circuit is from General Electric in a 1966 documentation. This type of component is rare today.
Found in a 1990s US publication, this alarm circuit detects when a light beam is interrupted. Optical...
This circuit for a commercial compact digital multimeter was found in the March 1979 issue of...
The flasher we present was found in a 1982 publication, shown in the figure. What we have is a...