This circuit is from American documentation from the 1980s. The circuit can make use of any common NPN transistor and the power comes from two small batteries.
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...