| 摘要 |
Movement or removal of a display object placed on a base is detected by a switch mechanism for closing an electrical circuit, having an elongated plunger and a device for maintaining the throw length of the switch mechanism substantially constant and independent of the distance the plunger is depressed upon setting of the alarm. Detection of extremely short plunger travel is enabled without special adjustments in the plunger length. A "tilt" switch may be added for added sensitivity. A plurality of bases, each with its own switch, may be grouped with a single signalling device to provide an alarm system. Portions of the circuitry may be grouped in modular form for introduction into the base housing.
|
