555 as RS trigger
555´s behavioural model Ring Counter ?? 5MHz
555´s component level model Ring Counter
Self-loop-back Oscillator . . .
. . . finding the limits
Re-trigger from timing capacitor
Re-trigger from merged threshold inputs
Re-trigger from low going output
Simple PWM -- there´s a Clock triggered CC v. of it in a prev. post -- but the CC clock triggering showed out multiple problems with this component level model (which are more easy to overcome using hardware other than 555 timer) . . .