摘要 |
An electric horn is disclosed which has two electromagnets which are alternately and repeatedly energized so as to move a diaphragm to and fro in opposite directions. As a particular feature, a controller is disclosed which energizes these electromagnets at a frequency which is dependent upon ambient air temperature, so as to keep the wavelength of the emitted sound constant to provide a better match for the horn trumpet of the electric horn and cause better resonance therewith. |