This power control from a 1968 Motorola manual shows how to use a contemporary diac as a zero-crossing detector. The SCR is of the type depending on the power of the load.
This circuit is from an old publication from 1977 and can be implemented with more modern...
This basic buffer circuit can be implemented with other operational amplifiers. The circuit is...
This circuit can be applied to other 3-terminal regulators and equivalent transistors can be used....