The circuit shown consists of a power stage for relay excitation. 2N3053 can be a BD135 and 2N406 can be replaced with a BD136. R3 depends on the trigger voltage.
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,...