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.
Found in a 1964 Electronic Design, this circuit shows how to modulate a signal with a dynamic low...
This circuit is from an 80's documentation, firing when the input voltage exceeds 5 V. The SCR can...
The transistor used is one of the first power Darlingtons with a collector current of 3 A. The...