This dimmer for the 120 V (117 V) network was found in the magazine Electronics Now of August 1995. The triac is according to the load that must be ohmic.
This circuit is from a 1974 publication, but it can still be easily assembled today with BC548...
Found on Popular Electronics in the 1980s, this circuit detects a change in air pressure using a...
This 3-transistor amplifier stage was found in documentation from 1963. The transistors are made...