| 摘要 |
Alarm system for motor vehicle, incorporating an alarm control unit (10) which is powered by a main battery (30) of the motor vehicle, a siren unit (26) likewise powered by the main battery (30), and a back-up battery (28) in the siren unit (26) which is arranged to power the siren unit upon failure of the power supply from the main battery (30). To simplify and make such an alarm system safer, it is proposed inter alia that upon said failure of power supply from the main battery (30) the back-up battery (28) be arranged to automatically power also the alarm control unit (10). |
