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.
We find this circuit in a 1974 Motorola PUTs (Unijunction Programmable Transistors) documentation. The circuit...
This circuit releases a lock only if the correct 4-digit sequence is entered. The circuit uses...
This alternating flasher was found in a 1980s documentation. The transistors may be equivalent such...