| 摘要 |
PCT No. PCT/AU89/00065 Sec. 371 Date Aug. 3, 1990 Sec. 102(e) Date Aug. 3, 1990 PCT Filed Feb. 16, 1989 PCT Pub. No. WO89/07814 PCT Pub. Date Aug. 24, 1989.The present invention provides a security system for an environment such as a building, safe or motor vehicle. The security system can be disarmed only by using a voltage level which exceeds the voltage level normally available in the environment. The security system comprises means for disarming the system, such means being responsive only to a voltage level exceeding the voltage level normally available in the environment. The security system further comprises means, including a capacitor, for generating a disarming voltage level which exceeds the first voltage level and to which the disarming means is responsive so as to disarm the system. |
