Abstract: A luminaire includes a fixture including at least one light source, a power supply mounted to the fixture for supplying power to the light source, and circuitry in communication with the power supply for controlling the power supplied to the light source dependent upon an ambient temperature, such that the power supplied to the light source is reduced when the ambient temperature falls below the threshold ambient temperature in order to limit the power supplied to the light source while an output of the light source remains substantially constant despite the limited power supplied. A system for indicating when maintenance is required on one or more luminaires in a building by sensing ambient temperatures and determining a difference between the ambient temperatures sensed and providing an indication signal that the determined difference between the ambient temperatures is at or above a threshold difference.

Abstract: Securing and monitoring of a computer or asset against theft and vandalism can be achieved using an electronic assembly. Using sensors to monitor motion, vibration and light intrusion into the computer cavity, a decision is made to alert a remote surveillance station and trigger an audible alarm and/or disable the asset either permanently or temporarily through electronic means. The electronic assembly is a self-contained unit with battery backup capable of communicating to a central surveillance station over a LAN/WAN/Internet. A remote monitoring station linked to the Internet communicates to the asset(s) being monitored and provides an updated status to security personnel over any communications link deemed appropriate.

Abstract: A telephone line interface circuit with d.c. amplifiers coupled to tip and ring paths is protected against transient voltages by a crowbar-type protection device coupled via a diode bridge to the tip and ring paths, positive and negative terminals of the diode bridge being connected respectively to ground and via a diode to a negative supply voltage line for the amplifiers. The diode prevents discharge of a capacitor, coupled between the negative supply voltage line and ground, through the protection device when it conducts. A locked up state, in which the amplifiers maintain holding current to the protection device after a transient voltage, is avoided by further diodes coupled from the negative terminal of the diode bridge to inputs of the amplifters, or by controlling a current limiter to interrupt current to the capacitor when the diode is reverse biased, so that the capacitor discharges.

Abstract: A electronic circuit board arrangement includes a main circuit board on which components are mounted, with component leads passing through holes in this board. Additional components are provided on an auxiliary circuit board at least part of which is directly against the main board, either on the component side underlying components or on a soldering side of the main board. The additional components are connected to the component leads via conductive tracks on the auxiliary board. The auxiliary board can be flexible to also extend over components on the main board. The arrangement is particularly useful for adding additional components to an original circuit design.