Ask an Expert: Veggie Power Science Fair Project: Piezoelectric Buzzer

[niffer71]

My son is going to be experiment with the power of fruits and veggies for his science fair project. We found the kit we could buy containing all the materials to be a bit pricey, so went to our local electronic stores and found everything we need. However, the instructions just say "piezoelectric buzzer", and there are different voltage buzzers available. Does anyone know which voltage would be appropriate for this project? Thank you.

[HowardE]

A potato battery will give you about 0.5 to 0.85 volts and just a few (<10) milliamps. Popular piezo buzzers are 1.5V at 30mA which is a good voltage but it takes a lot of current. The one in the kit is likely to be a standard one that will run as low as 3V on as little as 7mA (http://www.jameco.com/webapp/wcs/stores ... 2120452_-1 or http://www.amazon.com/3-20V-Continuons- ... B010V4W5BQ). The lower the voltage and current, the better.

If the buzzer won't run on DC, or it requires 5 or more volts or 20 or more mA, that's not the piezo you're looking for.

Howard