This circuit is from a 1968s Motorola documentation. The load can range from 10 to 100ohm and the transistor supports a modern equivalent such as 2N2222 or BD135.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...