Abstract: A signal transmitter for transmitting control signals is fitted to a key element so that signals can be transmitted to an operating device with which the key is used. Illustrative is the fitting of an automobile ignition key to a fob housing in which the signal transmitter is carried. The head part of an ignition key is subjected to a punching operation to shear off a first portion of the head part leaving a remaining head part portion with wings disposed laterally at opposite sides of the key shank part. Holes are drilled in the remaining head part portion and the remaining head part portion is received in an anchorage in the housing with the key shank extending through a notch in the housing. The remaining head part is then secured to the housing with screws passing through the lateral wing openings and into anchorage posts formed in the housing.

Abstract: A method and apparatus using a PIN number for preventing theft of cellular telephone service is disclosed. The PIN is requested silently by a visual display panel and entered silently by recalling the number from memory. The PIN number is transmitted as a hookflash message during each call at a limited, variable delay after the mobile unit switches to the voice channel and the cell site requests the PIN number by pressing a single key. This one-touch PIN transmission is also compatible with one-touch dialing, automated mail access, and linked number operations.

Abstract: An easy-to-install automotive security system mounts a siren assembly in the engine compartment and a sensor assembly in the passenger compartment. The assemblies are in wireless, radio frequency communication, thereby eliminating wires extending between the compartments.

Abstract: Battery power consumption of a cellular telephone is minimized during the stand-by mode by detecting when a received message is intended for another telephone, and for reducing battery power to at least one of the electronic components at the telephone when the transmitted message is intended for another telephone. Power is restored when the next transmitted message is expected to be received by the telephone.