Hester Street is a 1975 film which tells the story of an immigrant Jewish woman who clings to the "old ways" while her husband and son succumb to the American culture in turn-of-the-century New York City. It stars Carol Kane, Steven Keats[?] and Paul Freedman[?].
... light emitting diodes powered by a little generator embedded in the gyroscope.
The physics of this device looks confusing at first sight, but is surprisingly simple. ...