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.
The filter shown in the figure, suggested by Motorola, operates at a cut-off frequency of 1 kHz,...
The purpose of this circuit based on Maxim's MAX9022 is to find faults in multiple cables. The...
This circuit is suggested by Motorola in its 1990 Linear Databook. The speaker (or headphone is 32...