This constant current source for high voltage loads was obtained from a 1967 General Electric documentation. The components are of the time, but allow equivalents.
Maxim MAX20056B 6 Channel High Brightness LED Controller Maxim Integrated makes available through...
We found this circuit in American documentation from the 1980s. Transistors can be of general use....
This circuit for car engine spot adjustment was found in an 80's Radio Electronics. The circuit...