| 摘要 |
Retail articles are guarded by protective elements (1) which are shaped like badges and secured by a pin (7) which is electrically conducting. Each protective element (1) contains an electronic circuit which includes a radio transmitter, an audible alarm and an electromagnet detector. If the pin securing the protective element (1) to the protected article is broken a transistor conducts and causes the radio transmitter to send a coded signal (2) to receiver beacon (3). The audible alarm (23) is also operated. If the article is taken through the security gate without breaking the pin the electromagnetic detector operates both the audible alarm (23) and the radio transmitter.
|
