| 摘要 |
<p>An anti-theft device is designed to operate an alarm such as an audio-warning device (21) or a radio transmitter in the event of any unauthorized attempt to use the object being protected, for example a safe or a vehicle. A first alarm circuit (26, 27) comprises an alarm contact (28) in series with a disconnecting switch (29) which is opened by a neutralization circuit (34, 33, 37). Said neutralization circuit passes through a control unit (33) comprising a set of switches (1-18), some of which (3, 4, 7, 10, 12) are connected in series in the neutralization circuit and constitute a numeric code. Other switches (1, 2) in this unit are trapped by parallel connection into a second alarm circuit (50, 51, 26). The alarm contact (28) can be coupled to a member used for operating the object being protected, such as a handle (54) for the safe door (53).</p> |
