For the next iteration of Swordfight, we wanted to controllers to make a lot more noise. We’re swapping out the tame piezo speakers we used before for bicycle warning horns. They are CRAZY loud. If there ever was a chance that someone didn’t notice you playing Swordfight, these horns will shatter it.
Pictures show the original packaged device and its liberated components. It includes a 556 timer chip, probably generating a square wave, and a transformer to step up voltage from the 9V battery to whatever the buzzer needs. The trigger button is s standard tac button you might use on a breadboard.