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UM3561 Problem with circuit

AJames472

New Member
Hello,

Newbie to electronics here....

I have built a small circuit using the UM3561 chip

I am only able to get the police siren sound and have tried the various jumper connections to get the other sounds

Can anyone suggest what I should check on the pcb as to why it is not functioning correctly please?

I have attached the circuit and component pdf

Many Thanks

Alex
 

Attachments

  • 70-9116_v3.pdf
    2.7 MB · Views: 95
Check the connections between the IC, pins 1 & 6, and the jumper pins??

From the IC data sheet, J2 (with J1 open) should give three different sounds: No jumper is police siren, jumper to ground (pins 2-3) for ambulance siren, jumper to VDD (pins 1-2) for fire siren.

If J2 is fitted, that should force the machine gun sound, regardless of any J2 setting.

If it's not working with all the correct connections, the IC may be faulty or a fake..
 
Thanks for your reply
I have used the chip on another circuit and get the same issue so I agree with you that the chip is faulty, that will teach me to buy it on ebay......
 
1702871179647.png

p6= SEL 1
p1= SEL 2

R=~200k p7 to p8
 

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