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how can i increase and rise the voice in my circuit ? Answered


My project called " Four Tone Siren " 

this is the circuit for my project .... I really need to increase the voice

because it's very small you can't hear it except if you put the circuit close to you  

and i only hear 3 tone and my project is 4 tone.

 can you tell me please what is the reason ?

my final project after 2 days please :( 

this is my parts :

IC UM3561
Resistance = 220 Ohms
Condenser 100Mfd
Transistor BC548
Battery Container 3V

4 Replies

iceng (author)2012-05-12
layal_1 (author)iceng2012-05-13

thank you I will try your circuit then tell you :)

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steveastrouk (author)2012-05-12

The datasheet that Canucksgirl flagged yesterday has all you need.


Your problem is that the resistor to the base of the transistor is too small, and its over loading the chip.

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layal_1 (author)steveastrouk2012-05-13

than you I will read the datasheet ... . it's very helpful :)

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