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 is the basic configuration of a monostable TTL with the 74121. The trip is done with an NC...
This fixed source configuration with 78xx series regulators has already been explored in several...
In the figure we have a TTL logic interfacing circuit as CMOS logic using a 6N139 optocoupler...