Abstract: A wireless alarm system (10) employs two-way transceivers (32, 60) in a network of smoke detectors (16), a base station (12), and other sensors. A keypad (14) is not needed because the system is reset by pressing a Test/Silence button (66) built into every detector or sensor. A siren is also eliminated because a sounder (64) in every detector sounds an alarm when any sensor is triggered. This is possible because every detector includes a transceiver that can receive alarm messages from any other detector. AC power wiring is also eliminated because the base station and sensors are battery powered. Only a telephone connection (48) is needed if the system is to be monitored. In apartments or dormitory installations, smoke detectors in one apartment relay alarm messages to the next apartment, and onto the next, and so on, to a centralized base station for the entire facility.

Abstract: A key container has a body with a chamber, an access opening that communicates with the chamber and a cover that can be locked in place over the opening. A key-operated locking assembly is attached to the cover and engagable with the body to lock the cover in place. The cover can be engaged with the body and locked in place without operating the key.

Abstract: A location or other description of the source of a transmission is inserted into the communication as a prefix to transmitter data. A multi-format receiver emits a sequence of different handshakes until the transmitter begins to respond. The receiver stores the prefix and a descriptor of the last handshake prior to the transmitter response. Subsequent signals with a stored prefix are greeted immediately with the stored associated handshake.

Abstract: A cover for an electronic device having a screen that includes a window and at least one device operating feature. The cover is coupleable with the electronic device such that the window of the cover overlies at least a portion of the screen and the electronic device is operable with the device operating feature of the cover.

Abstract: Various enhancements are provided to a pushbutton lock to enhance its security. One is the provision of button tips that are mounted on the ends of the button assemblies and spring-loaded to protrude from the face of the lock, regardless of whether the underlying button is “in” or “out.” By this arrangement, a bystander cannot readily see the button combination by the pattern of depressed buttons. This arrangement also reduces tactile feedback between the underlying button assembly and the externally available button tips, increasing resistance to pick attacks. A further enhancement is the provision of button bars between adjacent pairs of button tips. Whenever any of the button tips is manually depressed, the corresponding button bar is pressed into engagement with, and prevents movement of, a member that must be moved in order to unlock the lock.

Abstract: A motion detector combines an FCC approved homodyne pulsed range-gated radar (“RGR”) detector (10) and a PIR detector (158). Narrow microwave pulses are transmitted at a predetermined pulse repetition frequency (“PRF”) and the pulses are reflected by a target. The RGR detector senses the presence of moving human sized objects within predetermined ranges. Moving objects beyond the ranges are not sensed. The RGR detector employs a pulsed microwave oscillator (12) that is triggered by a system clock (14) and immediately retriggered after a 3 to 100 nanosecond delay (20). The duration of each pulse is 3 to 20 nanoseconds with a half-sine envelope shape. The RGR employs a homodyne detector (36) and shares an antenna (38) with the transmitter. The receiver range is determined by the delay imposed between the transmitted pulses, the first being a transmitted pulse and the second being a local oscillator pulse. Each received 5.8 GHz pulse is mixed down to a baseband by the homodyne detector.

Abstract: Various enhancements are provided to a pushbutton lock to enhance its security. One is the provision of button tips that are mounted on the ends of the button assemblies and spring-loaded to protrude from the face of the lock, regardless of whether the underlying button is "in" or "out." By this arrangement, a bystander cannot readily see the button combination by the pattern of depressed buttons. This arrangement also reduces tactile feedback between the underlying button assembly and the externally available button tips, increasing resistance to pick attacks. A further enhancement is the provision of button bars between adjacent pairs of button tips. Whenever any of the button tips is manually depressed, the corresponding button bar is pressed into engagement with, and prevents movement of, a member that must be moved in order to unlock the lock.

Abstract: The invention provides a method and apparatus for processing video data signals to generate a time division multiplexed video signal which incorporates a maxima number of fields from successive selected video input signals. The invention provides dual video decoder channels associated synchronisation circuits for generating an early synchronisation signal. The early synchronisation signals are applied to control inputs of the video decoders to enable reading of their output earlier than would normally be possible, avoiding delays in the combining of successive fields of video information in the video TDM signal. The provision of dual channels avoids delays due to lack of synchronisation between the different video sources.