micro-squeaker

This circuit is by way of being an electronic joke. The complete circuit comprises only one transistor, one ca- pacitor, a miniature transformer and a headphone. The transistor can be any germanium type; the transformer can be any miniature type with a turns ratio between 3: 1 and 10: 1. At supply voltages as low as 0.2 V the headphone produces a distinct sound. Current consumption is then of the order of I OµA, power consumption is less than 2µW. The joke of this microsqueaker is that it is not fed from a `normal` current source, but that the gifts of nature are called upon.