This circuit only works with incandescent lamps and the frequency is adjusted in the pot, depending also on the capacitor. The triac must be equipped with a heat sink. The circuit is from an 80s manual.
This 5.1 MHz oscillator was found in a 1980s American documentation. The used operational...
Division of a digital signal up to 4098 can be done using the 4040 IC as shown in Figure bellow....
Placed inside the refrigerator, this circuit triggers an oscillator when the part is opened...