This circuit with 1% regulation aims at replacing mercury cells. We found it in a 1967 documentation. Transistors can be replaced with modern equivalents.
This half-wave regenerative control was found in an old RCA manual. The circuit can be designed...
I found this circuit in a documentation about thyristors from the 70s. The circuit uses a diac...
Up to some minutes intervals can be obtained from this circuit. The circuit can use a lamp (or...