This circuit was found in a 90’s Popular Electronics. The power transistors must be equipped with radiators and the transformer has a 2 to 5 A secondary.
This basic configuration can be found in a lot of articles on this site. In this case, the relay...
This circuit is from American documentation from the 1980s. The transistors are general purpose...
The circuit is simple, as it uses only one transistor and a relay that can be MC2RC1 or MC2RC2,...