This traditional crystal oscillator configuration can use any CMOS gate configured as an inverter. R1 has values from 1 to 5 M ohm and R values around 10 k.
Found in a 90's EDN, this circuit generates signals in the frequency range given by the graph. The...
The figure shows a circuit that shows how to control an optodiac to trigger a triac from the...
This circuit, from an American documentation from 1975, can be assembled with modern transistors such as...