This circuit uses a photo-SCR or LASCR that is not a common component today. The relay depends on the load, and the power is supplied by the power grid.
This circuit is from a 1968 Electronic Design. The components are from the era and the operating...
In this charger the current is limited by the incandescent lamp. Lamps from 40 to 100 W can be...
This circuit was presented in a January 1990 Radio Electronics magazine article as part of a home...