This siren alarm circuit diagram is based on a specialized IC UM3561 , which is a low power CMOS LSI specially designed for this type of applications . The UM3561 contains all needed parts ( oscillator , selector circuits , programmed mask ROM ) to simulate siren sound using few external components .
The siren circuit require a power supply circuit around 3 volts and has a low current . The UM3561 siren sound generator circuit has possibility to generate four types of sounds : police siren , fire engine siren , ambulance siren and machine gun sound .
The transistor used in this project must be 2SC9013 , 2SC8050 or similar type .
The speaker used at the output must have 8 ohms impedance and a 0.2 watts power .
As you can see in these three circuit diagrams , the configuration for the siren is very simple .
UM3561 electronic siren circuit diagram
Police siren , fire engine siren , ambulance siren and machine gun sound .
Police siren , fire engine siren , ambulance siren .
Police siren and machine gun sound .
