This circuit uses a feedback integrator. We found it in Ferranti's transistor manual from 1974. Transistors are general-purpose types at the time.
We found this circuit in Texas Instruments documentation from 1986. The circuit produces a...
In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The...
We found this mains-powered switch circuit in Electronics Now magazine from July 1994. It could be...