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 was taken from the 1974 Ferranti transistor manual. Transistors are common types at...
This circuit monitors the current of a series of 40 V lithium battery packs connected in series....
This 1970 Philips circuit uses a mechanical counter. The circuit is triggered by a reed switch...