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 a General Electric documentation from 1965. The circuit is full wave for...
We found this circuit in the Texas Instruments' Linear Circuits Applications. It uses an...
In the presented circuit it is possible to vary the frequency of the rectangular signal produced. This...