This circuit is from LinearTechnology Applications of 1997. The circuit uses components of the time used to raise the voltage of a battery from 3 to 6 V.
MCP19124/5 Contains Independent Voltage and Current Control Loops Plus a Full Suite of...
This circuit is from an old documentation from the 70s, so the transistors used are not common....
This small transmitter can act as a wireless microphone operating in the medium wave range,...