| 摘要 |
An alarm device especially suitable for alarm clocks or timers is described, whose alarm signal can either be interrupted for a certain period of time or shut off by an acoustic signal, for example that formed by the human voice. As a result of its low power consumption, the alarm device according to the invention can also be used in battery-powered devices; when installed in an alarm clock or timer, inexpensive mass production is also made possible by using already existing integrated circuits. The alarm device according to the invention is functional even when the acoustic signal produced by the user is only of very short duration or when the alarm signal is delivered as a continuous tone. Advantageously, the alarm device can also be so designed that it delivers an alarm signal at least for a short time when someone is speaking when the alarm signal is triggered and other noises with frequencies outside the frequency range of fundamental tone of the human voice interrupt or shut off the alarm signal. |
