This circuit was found in a Popular Electronics from the 90s. It is intended to power the filament of old radio valves in recovery works. It is indicated for tubes that use 5 V of filament.
In the figure we show a trigger circuit for triacs with a unijunction transistor. The circuit is...
The oscillator in the figure has its frequency determined by the crystal. The indicated value is...
This circuit was found in the November 1959 Radio Electronics magazine; The circuit generates a...