This circuit is from American documentation from the 1980s. The transistors are general purpose types and the relay can be 6 or 12 V depending on the supply voltage.
This configuration was found in old documentation and is valid for most general purpose NPN...
We found this good power amplifier with the LM12 integrated circuit in the March 1989 issue of...
March 2017 - The new 2W DC-DC converters from Recom can now be porchased at Mouser Electronics. The new...