This power stage with two transistors was found in Radio Electronics magazine from October 1963. The transistors must be equipped with heatsinks and the supply voltage is 12 V.
This circuit for link or alarm was found in the Encyclopedia of Electronic Circuits Volume 5 of...
This circuit is from a Popular Electronics of the 90's. Any power MOSFET can be used. The circuit...
This circuit extends the scale of a milliammeter. We found it in a documentation from the 60's. The...