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.
We found this circuit in English documentation from 1996 for PCs. The circuit is for common...
This circuit uses an operational amplifier to simulate an inductor. The circuit is from old...
Using this circuit the lamps glow in sequence in a speed given by the capacitors. The SCRs present a...