This Schmitt trigger was found in a 1969 Ferranti documentation. Transistors may be modern equivalents.
With the components indicated, the circuit oscillates at 20 MHz. The coils and capacitors can be...
The trigger shown in the figure, built around a 4093 can generate pulses that reach 1 hour with a...
This circuit was obtained in an old American documentation, remembering that the 566 is the double...