| 摘要 |
PROBLEM TO BE SOLVED: To provide an electronic device for generating an audible alarm or music.SOLUTION: An electronic device (1) is configured to generate an audible alarm or music. The electronic device (1) comprises a coil or an inductor (L1) and a buzzer including a capacitor (Cb) connected to the coil in series. When the electronic device is actuated, the buzzer generates an audible alarm or music. In order to generate a derivative of a signal from the capacitor, the electronic device further comprises a differential circuit (3) connected to a connection node between the coil and the capacitor and a comparator (4) for comparing a differential signal (Vder) from the differential circuit (3) with a reference voltage (Ref), in a feed-back loop. The comparator supplies an output signal (Vcomp) to the coil, and amplifies a signal on the capacitor so that the buzzer generates at least one audible alarm.SELECTED DRAWING: Figure 1 |
