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Why this buzzer is not working?

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jayanth.devarayanadurga

jayanth.devarayanadurga

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Why this buzzer is not working? I need to drive a buzzer which works like this.

it has 2 pins. One pin is longer than the other. The shorter pin has to be connected to ground and the longer pin has to be given a 2 KH - 4 KHz square wave. It doesn't work if direct 5V is given.

I am attaching my project files. The buzzer doesn't make any sound. My buzzer is a 5V type.

91442d1369304160-gassensor.png
 

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Is the buzzer not working in real test??? In the simulation change the value of buzzer voltage to 3v or 3.5v. By doing this, the buzzer produces sound while simulating.
 
jayanth.devarayanadurga said:
Why this buzzer is not working? I need to drive a buzzer which works like this.

it has 2 pins. One pin is longer than the other. The shorter pin has to be connected to ground and the longer pin has to be given a 2 KH - 4 KHz square wave. It doesn't work if direct 5V is given.

I am attaching my project files. The buzzer doesn't make any sound. My buzzer is a 5V type.
Click to expand...

Change the circuit as below
gassensor.png
 
Yes. The Circuit works if I make the Buzzer voltage 3 V in Simulation. I want to know will it work if I don't make anychanges in the real hardware. I will be giving %V to Collector of transistor and a 2 KHz pulse to base of transistor.

- - - Updated - - -

@iukhan

I can't connect one end of buzzer to +VCC. It doesn't work. One pin needs 2 to 4 KHz pulse and other pin has to be grounded.
 

jayanth.devarayanadurga said:
The Circuit works if I make the Buzzer voltage 3 V in Simulation. I want to know will it work if I don't make anychanges in the real hardware. I will be giving %V to Collector of transistor and a 2 KHz pulse to base of transistor.
Click to expand...
As per your schematic, you are using the transistor in common collector mode. In this configuration the output voltage at buzzer will be from min 3.8V to max 4.4V. In real hardware 3.8V should activate the buzzer. But I will recommend to check the minimum operating specification of the buzzer.

I can't connect one end of buzzer to +VCC. It doesn't work. One pin needs 2 to 4 KHz pulse and other pin has to be grounded.
Click to expand...
The transistor in the circuit I recommended, is in switching configuration. In this configuration the buzzer will receive full 5V. So there will be no doubt of not functioning of buzzer.
I don't know what special type of buzzer you have, to my experience and theoretically it is same to apply positive pulses to one pin and tie the other pin to ground, or tie the buzzer to Vcc and apply 0V (ground) pulses to other pin.
 
jayanth.devarayanadurga said:
I can't connect one end of buzzer to +VCC. It doesn't work. One pin needs 2 to 4 KHz pulse and other pin has to be grounded.
Click to expand...

Stupid Question: buzzer just buzz, you put tension on pins an they just make loud sound. All my buzzer work this way(5V, or 12V or 15V -i have all tension and size)
Your looks more like a speaker.
Which one is your?

W
 
This may sound silly but you are only putting about 1.5V across the buzzer anyway. Almost all the current is being sunk through the LED. At the very least, add a resistor in series with the LED to limit it's current and allow the voltage across the buzzer to reach Vb - Vbe.

Brian.
 
It is now working when I removed the LED. The working voltage of buzzer is 5V to 12V. I gave 12V and GND to buzzer and it worked but the sound was very low. It is working either way. The vendor from whom I bought the buzzer told that it doesn't work if DC is applied but 2 - 4 KHz square wave has to be applied to make it work.
 

Some buzzers are self oscillating. They do not require pulse width. And some needs few KHz to produce sound.
Its upto you what buzzer you have or you are going to choose.
As what "betwixt" said, the LED requires a resistance, say 470R to 1K. Or it will virtually act like a forward diode....
 
The LED is put in paralle with buzzer and without current-limiting resistor, then the voltage on the buzzer + is always voltage-drop of LED, 1.8V more or less. that why no beeps.
 

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