How to use pc buzzer..

[koolguy]

Hi,

I have seen two type of buzzer piezoelectric..one work directly to power supply and secound does no it is used in PC...
here is pic of it pls tell how to use it with uC...??

**broken link removed**

 

[Ian Rogers]

The "buzzer" that you pictured is a self contained unit... the square wave unit that drives the piezo element is within..

On a PC its a real speaker you need to control the signal to it....

 

[Joe G]

think "PWM"

 

[dr pepper]

Some pc beepers operate direct from 5v dc, and others ac, you could write some software to toggle a pin of your microcontroller at say 2khz, this can then be connected to your piezo, to get increased voltage and volume you could use a transistor with the inductor accross the piezo.

 

[Nigel Goodwin]

Some pc beepers operate direct from 5v dc, and others ac, you could write some software to toggle a pin of your microcontroller at say 2khz, this can then be connected to your piezo, to get increased voltage and volume you could use a transistor with the inductor accross the piezo.

Even better, connect the piezo between two pins and feed it in bridge mode, giving four times the power

I sent a modification like this to Practical Electronics for one of the projects they published.

 

[georgetwo]

Hi,

I have seen two type of buzzer piezoelectric..one work directly to power supply and secound does no it is used in PC...
here is pic of it pls tell how to use it with uC...??

**broken link removed**

this type of buzzer is simple to use, you don't need to use pwm cos it generates its own frequency .
I use to switch it with a transistor and it works with 5v and louder with 12v. unlike speakers,
you don't generate frequency, you switch with ones and zeros.The frequency also changes when its supply
voltage changes, you can also take advantage of that to change the way it sounds.

 

[dr pepper]

A piezo needs ac, ones that operate from dc have a oscillator inside them.
You'd only use pwm on a piezo if you wanted to control volume, or if you had an inductance accros a peizo cell.