This circuit is from Motorola's Linear Interface ICs of 1993. The integrated circuit is not common and the Triac is chosen according to the power of the controlled load.
In the figure we have the circuit of a simple humidity sensor with the 4011. The circuit was found...
We found this receiver for the 144 MHz band in a European publication from the 1970s. The circuit...
We found this circuit in an ancient American documentation. It can be adapted to operate in other...