| 摘要 |
Alarm apparatus (1) for determining if a vehicle is moved while the alarm apparatus (1) is armed. The alarm apparatus (1) comprises a global position sensing circuit (12) which operates under the control of a control circuit (6). The control circuit (6) reads the current position of the vehicle from the global position sensing circuit (12) at ten minute intervals to check if the vehicle has been moved. Each current position is compared with the first position of the vehicle after the alarm apparatus (1) has been armed, and the difference between the current and first positions is determined. If this difference exceeds a predetermined difference the control circuit (6) activates an interface circuit (14) for powering up a mobile telephone (15). On establishing a telephone line with a central monitoring station, a signal is outputted by the control circuit (6) to the central monitoring station indicating that the vehicle has been moved and the current position of the vehicle. |
