User alerting method and apparatus for use with security systems

摘要

A vehicle security system can be armed or disarmed by an authorised user who is alerted if the alarm system is armed prior to the use of the vehicle. The warning that the alarm is armed is triggered by sensing a change in the vehicles' battery indicating entry to the vehicle. A piezoelectric vibrations sensor may be a part of the sensing system able to detect a running engine or able to generate warning sounds. The system preferably uses a comparator and capacitor to detect changes in the battery 121 voltage. The voltage comparator circuitry 111 or substantial parts of the alarm system may be contained within the battery housing 153.