| 摘要 |
A device for determining whether a darkened enclosure has been opened by an unauthorized user. Though it responds to the presence of light, the device may be actuated either in light or in darkness without compromising its performance. When placed into a darkened enclosure, the device has the capacity of informing the authorized user of a possible unauthorized opening. After an unauthorized opening, an audible alarm would be triggered for a predetermined period of time. Subsequent to the cessation of this audible alarm, the authorized user by viewing the status of a light emitting diode after depressing an on/off switch, can determine whether an unauthorized user has gained access to the enclosure.
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