Martian
Senior Member
Are you planning to power this thing with 27 volts? It's only rated for 6-18V, so the full voltage from three 9V batteries will ruin it.The pdf document for your piezo buzzer shows it to need a square wave input driver circuit. So the best you will get is click sound when you turn on the device.
I might get another one at radio shack.
How about one like this? - RadioShack® 76dB Piezo Buzzer