This circuit was found in an American medical documentation from 1970. The circuit rejects the 60 Hz noise pickup and generates 2.5 Hz signals. Equivalent components can be tested.
This 1965 General Electric circuit uses a "Thyrector" that is a suppressor of the time. The...
August 2017 - Mouser Electronics announced the availability of a full range of Mean Well regulated DC-DC...
This sophisticated alarm with traditional components was found in an ancient American...