This well-known circuit version of the siren was obtained in a Colectro Handbook from the 70s. The transistors are of general use, with Q2 being a BD136 for greater power with power from 6 to 12 V.
This circuit was found in 80's Popular Electronics. Transistors are commonly used. The...
This low current source uses some components that are hard to find in ours. The transformer is a...
This circuit is from a manual based on information from Japanese components from 1981. The power...