![]() The exact opposite thing happens too, when a a piezoelectric element is subjected to varying pressure, it produces voltage.Īs you've seen before, self drive piezo buzzers are constructed with an extra electrically isolated feedback electrode. ![]() This flex force bends the ground plate up and down. When A voltage is applied to the electrodes of the piezo element, they produces flex in either way. Now all components fits nicely inside the buzzer's housing. I also replaced the 5mH coil with a 50 turn coil on a ferrite toroid. So later removed those and and soldered two thin and very flexible wires, that just worked. The flex force ain't that powerful to overcome the pressure from connecting wires.ĭid you notice the two copper coils in the above picture ? I used them to minimise the pressure from connecting wires, but it was pretty impractical. Why ? The piezo element produces a very little displacement, possibly in range of few micro meters only. The wires connecting the buzzer's Main and feedback terminal MUST be very flexible and thin, else the buzzer won't work ! My sample prototype, I opted for soldering the components to each other. As this piezo buzzer circuit uses very few components, so it also could be constructed by soldering the components to each other. The circuit is fairly simple, you can use a little piece of strip board to make it. Note the piezoelectric element's pinout, M is the main terminal, F is the feedback terminal and G is the ground plate. I used a 40 turn coil on a small ferrite toroid in the final design. You can use any coil from 1mH to 10mH or more, or even no measured value at all. ![]() The inductor coil's value and shape is not crucial. The blue wire is connected to feedback( F) terminal, red wire to the main ( M) terminal and the black wire to the piezo element's ground( G) plate. The Piezo element must be a three terminal one, like in the picture. One 1-10mH inductor coil, details below.One self drive 3 terminal piezoelectric buzzer. ![]() One BC548 transistor, or other similar NPN transistor.You're going to need few very basic components for this simple piezo buzzer circuit. ![]()
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