Found in General Electric's documentation from 1970, this circuit is indicated for the so-called “Solid State Lamp” (SSL). The LED symbol in the original diagram is inverted.
This circuit, which appears in other applications on this site, was taken from a 2000...
This filter for interference generated by motors via the power grid was found in the June 1972...
An old analog TV that is not in use can be turned into an oscilloscope for low frequencies...