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.
This circuit is from a 1991 publication. It divides the frequency of a TTL signal applied to its...
This circuit applies to other operational ones, other than the one indicated. The formulas next to the...
To small metal plates are used as sensor in this circuit. The skin resistance is enough to trigger the...