An inadvertent off-hook apparatus for use in a telephone system having a handset for automatically restoring an inadvertently off-hook telephone to an on-hook in order to receive an incoming call. The apparatus comprises a current sensing unit comprising a photo-coupler coupled to one of a tip and a ring terminal of the telephone line, for sensing variations of current of the telephone line in response to an incoming call and detecting a handset misplacement signal indicating that the telephone is in an inadvertent off-hook condition; and a control unit connected to the current sensor unit, for disconnecting the voice network from the telephone line to block the speech path in response to the handset misplacement signal, and for connecting the voice network to the telephone line to form the speech path to answer the incoming call.
A system for setting a wireless handset to an offhook condition when the handset is moved during the presence of a specified condition, such as an incoming call. A signal is sent to the handset to indicate an incoming call. If the handset is moved during the pendency of the incoming call, a sensor sends a signal to a controller indicating movement of the handset. A dedicated circuit may be employed to send an offhlook signal only when a movement threshold has been detected. If the signal reaches a predetermined threshold, the controller sets the handset to an offhook condition.
A switch operated re-positioning reminder for a cellular phone is equipped with a time counter which can actuate an alarm device after a preset time is counted down. The magnet operated reed-in-tube switch is made up of a pair of partially overlapped but separated reeds in a tube, or other types of switch. The time counter is a simple CPU contained program and a user can set up the prolonged time span as desired for the time counter. The alarm is a buzz, ring or speaker that can produce alarm sound. In a first embodiment, a PC board including the magnet operated reed-in-tube switch, the CPU, the buzzer and a battery can be housed in a rather thin shelter case wherein a magnet is attached to a cellular phone or other precious articles and the shelter box is fixed to the interior of a cellular phone case. In other embodiment, the magnet is fixed to a proper position of a cellular phone case, and the time counter program is merged with a conventional cellular phone circuit and the original ring system for the cellular phone is adopted as an alarm whereby as long as a cellular phone in either case is not repositioned in a cellular phone case in a preset time, the alarm device in either the shelter box or the cellular phone will be actuated to alarm so as to remind a user not to leave his or her cellular phone behind.
