This traditional dimmer configuration for incandescent lamps and heating elements was found in an RCA transistor manual. SCR can be a more modern equivalent like TIC106, depending on the power grid.
This circuit provides a 60 Hz or 50 Hz precision clock or time base, depending on the network. It serves...
With the values of the indicated components, this oscillator produces a sinusoidal signal of 1...
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...