[SOLVED] Problem in driving Buzzer from transistor BC547

As your first case not working so we cant say it will work for sure because a 555 doesn't take any current from the inputs.... so that makes the question on the SOURCE**

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In any case your circuit is not working with a load of buzzer and with a single battery so the only possible cause is your power supply may be your buzzer is low voltage rated or needs any series resistor, any way the clear problem is inability of source....

Ohhk Bro i will try with a larger power source & let u know if it works !!! But according to Buzzer's datasheet ,its rated Vtg is 5V only !!

I also tried with number of series resistors with Buzzer ! :-
1. some time it works with it ,but it depends on battery !
2. it reduces current through buzzer so resulting in very low sound !

thats why i dont want to use series resistor !

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@Venkadesh_M Hey Buddy !! You were right !! The problem was power source !! Inability to supply that much load !! I tried with new 9V battery & it worked properly for 555 & buzzer, but not for transistor & relay ! then i tried with My UPS battery 8-O 12V 7Ah :idea: ,,it worked with my existing transistor buzzer setup !! so now i got my lesson !! Thank you so much for taking efforts in solving my problem !!

:smile: nice to hear it solved....