| 摘要 |
An apparatus for alerting the user to the removal of an item such as an umbrella on mobile telephone or to the disappearance of a small child or a pet, comprises a transmitter, a receiver and an alarm. The apparatus is arranged as a primary unit, preferably forming part of a watch 20, cooperating with a secondary unit attached to the item. One or each unit transmits a signal which is received by the other unit and one or each unit sounds an alarm when the signal is interrupted. Preferably, several secondary units may be controlled by one programmable primary unit, and each unit has an individual identity so that the primary unit reacts to the absence of any of the recognised secondary units. The secondary units may comprise resonant or RFID tags and means for recognising a plurality of primary units. |
