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.
Lamp Control (CB25902E) This low-current control circuit has a lamp as a load, but can have other...
This circuit operates from 25 to 65 kHz depending on the transducer used and the settings. We...
This TTL module can be used in counter and many of them can be cascaded to counts up to 99, 999,...