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Siren Generator | UM3561 |


Hii Dear Maker welcome “DiY Projects Lab ” Today i’ll show you In this Article How  to build an  Siren Generator | UM3561 | Fire Engine, Police, Ambulance

UM3561 is an IC siren generator generally used in alarm and toy applications. Depending on the different Pin selection.



  • Typical Operating Voltage = 3V
  • 8-Pin DIP Package
  • Power On Reset

You can generate 4 different types of sirens which are – ambulance siren, fire siren, police siren and Machine gun. Here we will see how we can make these different siren sounds using different selections on the IC pin. So here are the different types of siren circuits that can be created using IC UM3561

– ambulance siren, machine gun sound, siren circuit and fire police.

UM3561 Pin Diagram



Pin 1 (SEL2) and pin 7 (SEL1) are the selection pins.  We can only use these two pins to select the siren sounds.

Block Diagram

speaker is drive with an external NPN transistor.  SPDT switch is used to turn the circuit ON & OFF.



1) IC UM 3561

2) BC 547 / TIP 32C

3) Speaker

4) Variable Resistor 47 K

5) Resistor 100K x 2

6) Push Switch



Double Transistor Amplification

In this Article i’m going to show you how to make 4 in 1 Siren Generator circuit using IC UM3561, it is a Melody generator IC –

1) Car reverse siren,

2) police siren,

3) fire brigade siren

4) Ambulance Siren

5) Machine Gun siren,

6) Car indicator siren,

7) Siren for Science project,

8) Warning Siren


Police Siren Circuit Create a police siren circuit you need to create the connections as shown in the following circuit.

Ambulance siren

                                                      For create the ambulance siren with um3561 , just connect pin 6 (SEL 1) with ground(-) to remove pin from battery positive(-) pin

                                                      Machine Gun Circuit can be used in games to make them more interesting. To create the sound weapon with IC UM3561, leave pin 6 unplugged and connect pin 1 to the positive end of the mix

3 In One Siren 🚨 Generator


  • 1x UM3561
  • 1x BC547 NPN Transistor
  • 1x 220KΩ Resistor
  • 2x 220Ω Resistor
  • 1x SPDT Slider Switch
  • 1x SP3T Slider Switch
  • 2x 2-Pin Male Header Pins
  • 1x Speaker
  • 1x AA Battery Holder (2 Slot)
  • 2x AA Battery

Circuit Schematic

NextPCB PCB Manufacturers Company 


1st Thanks NextPCB  for sponsor this project. Nextpcb offer  For New Customer, Your First Order Will Be 10 PCBs for just $0 at Free.

NextPCB   one of the world’s most professional PCB manufacturers based in China. With professional PCB manufacturing capabilities, for each file of our customer will be double-checked by more than 14 years PCB engineers. they handle the whole process of PCBs including the PCB assembly ,PCB manufacturing, testing and final shipment.

PCB Fabrication

I fabricated this board using the Iron Method.

I drilled four mounting holes in each corner with a diameter of 3mm.

The PCB size is 3.3cm X 3.3cm .

Circuit Assembly

Place and solder all the components into the PCB.

Author Of this Project :- Jonathan Pereira (Electro Guruji)

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