Process timer (CB21865E)

We found this timer for times of a few minutes in a 1974 Ferranti transistor manual. The relay is 37 mA sensitive type.

Permanent magnet detector (CB22463E)
We found this circuit in Popular Electronics from 1992. Transistors admit equivalents....
Operational Function Generator (CB14065E)
This circuit is from the 1972 RCA Linear Integrated Circuits Manual but can still be easily...
Crowbar (CB4862E)
This short circuit protection circuit accelerates the blown fuse in case of an output overcurrent. The...