Alarm system for a motor vehicle
First Claim
1. 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) arranged to power the siren unit upon failure of the power supply from the main battery (30), wherein upon said failure of the power supply from the main battery (30) the back-up battery (28) is arranged to automatically power also the alarm control unit (10) characterised in that the siren unit (26) is arranged to detect power offtake from the back-up battery (28) so that the siren unit (26) delivers an alarm if the power offtake exceeds a predetermined level.
1 Assignment
0 Petitions
Accused Products
Abstract
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).
6 Citations
8 Claims
- 1. 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) arranged to power the siren unit upon failure of the power supply from the main battery (30), wherein upon said failure of the power supply from the main battery (30) the back-up battery (28) is arranged to automatically power also the alarm control unit (10) characterised in that the siren unit (26) is arranged to detect power offtake from the back-up battery (28) so that the siren unit (26) delivers an alarm if the power offtake exceeds a predetermined level.
Specification