This circuit was found in a 80s American documentation. The zener diodes determine the points of action of each stage and the transistors can be general purpose types.
This high quality circuit with complementary symmetry was found in an Electronics World of 1966....
Found in an Electronic Design this circuit controls a headlamp by triggering a time determined by the...
This small switched regulator was found in an 60’s Optical Electronics. The circuit uses an...