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Could someone help me identify these components? Answered

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Hello everyone,
                            I was opening up a pair of  old piezo buzzers and found these inside(attached picture).Dunno what they are nor what they do but when I opened up a relatively new buzzer,I found that this has been replaced by a 470 ohm resistor.The rest of the circuit remains the same which include a few resistors,a BC 547 NPN transistor and a speaker.The observation is that the old buzzer produces a much louder noise than these new ones with the same volts and amps...Given all that,anybody seen 'em before?

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icengBest Answer (author)2013-12-07

Both are inductors which are better then resistors in buzz applications.
Resistors limit current flow but turn that excess current to Heat !
That is wasted away.

Inductors limit current by storing it in a magnetic field which is returned
later in a buzz cycle as the magnetic field collapses causing a louder sound,

A

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Adarsh_tronix (author)2013-12-09

So,Will the buzzer produce a louder noise with an inductor of a higher or a lower value?

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iceng (author)Adarsh_tronix2013-12-09

That is very hard to answer without a circuit schematic and the other component values.

Usually the inductor must resonate with the capacitor for the loudness to be at the highest.

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Adarsh_tronix (author)2013-12-07

Thank you everyone,So they are inductors huh?I believe their unit is henry....but any idea about the magnitude of inductance of these inductors ?I need to purchase some to try a buzzer of my own so I require the value.

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iceng (author)Adarsh_tronix2013-12-07

Put  some dimensions or a millimeter scale in a better picture.

In the meantime try 150 uH to 300 uH like this one.

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Adarsh_tronix (author)iceng2013-12-07

Thanks for the reply.I'll try the suggested inductors and I am working on the picture too.

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Josehf Murchison (author)2013-12-07

Ok they are inductors.
You have RC and LC oscillators.
The buzzer you have has an LC oscillator driver.
A pic of the whole thing would be better.

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benmurton (author)2013-12-07

this is an inductor, the resistors and transistors create the oscillating dc current to make the sound, then the inductor amplifies it. an inductor is just a coil of wire.

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mpilchfamily (author)2013-12-07