Fire siren mockup
Fire siren model that very simply and faithfully mimics the low and loud sounds that are normally heard when a fire siren is triggered. Supplied without 4,5 V battery.
This circuit is a combination of the circuits for the acoustic alarm and the sound switch. The audible signal is produced by a self-powered amplifier set by a 0,15 μF capacitor connected to the input and which allows it to oscillate. The 0,45 μF and 22 μF capacitors allow this signal to become a more pleasant sound. The RC chain, that is, the input resistance in combination with the 100 μF capacitor, determines the speed at which the sound increases and decreases. The period of growth and decrease of the signal is determined by the Flip-Flop of the control circuit, through the two RC chains, composed of the capacitors of 470 μF and the corresponding resistors of 12 and 10 KOhm.
- Welding30 W
- Electronic soldering wire (with flux)
|Construction time:||3-4 h.|
Be download for free of the instruction manual