This siren configuration found in a documentation from the 1980s can also be seen in many of our projects and in this circuit bank. Transistors are common, but Q2 can be of power for a higher voltage supply.
The L200 integrated circuit consists of a 5-terminal current regulator in a TO-22O enclosure that...
The load on this amplifier is 8-ohm. We found the circuit in a 1972 Motorola amplifier manual. The...
Published in Radio Electronics magazine in March 1963, this circuit uses 4 transistors of the...