Abstract: In a building fire alarm system, the light strobes of a network of strobes are synchronized to flash simultaneously. Each strobe has a charging circuit to charge a capacitor which discharges through a flash tube. Once a capacitor is charged, the charging circuit is disabled. A synchronization pulse is applied through common power lines to trigger discharge of each strobe capacitor through the flash tube followed by recharging of the capacitor.

Abstract: In a building fire alarm system, the light strobes of a network of strobes are synchronized to flash simultaneously. Each strobe has a charging circuit to charge a capacitor which discharges through a flash tube. Once a capacitor is charged, the charging circuit is disabled. A synchronization pulse is applied through common power lines to trigger discharge of each strobe capacitor through the flash tube followed by recharging of the capacitor.

Abstract: A smoke detecting chamber for use in a light-scattering type smoke detector is provided which includes a chamber cover that forms one side of the smoke detecting chamber. The chamber cover includes a plurality of first baffles that prevent external light from entering the smoke chamber. The smoke detector further includes a chamber base that forms another side of the smoke detecting chamber, the chamber base including a plurality of second baffles that intermesh with the first baffles when the smoke detecting chamber is formed.

Abstract: In a building fire alarm system, the light strobes of a network of strobes are synchronized to flash simultaneously. Each strobe has a charging circuit to charge a capacitor which discharges through a flash tube. Once a capacitor is charged, the charging circuit is disabled. A synchronization pulse is applied through common power lines to trigger discharge of each strobe capacitor through the flash tube followed by recharging of the capacitor.

Abstract: In a building fire alarm system, the light strobes of a network of strobes are synchronized to flash simultaneously. Each strobe has a charging circuit to charge a capacitor which discharges through a flash tube. Once a capacitor is charged, the charging circuit is disabled. A synchronization pulse is applied through common power lines to trigger discharge of each strobe capacitor through the flash tube followed by recharging of the capacitor.

Abstract: In a building fire alarm system, the light strobes of a network of strobes are synchronized to flash simultaneously. Each strobe has a charging circuit to charge a capacitor which discharges through a flash tube. Once a capacitor is charged, the charging circuit is disabled. A synchronization pulse is applied through common power lines to trigger discharge of each strobe capacitor through the flash tube followed by recharging of the capacitor.

Abstract: A shield for a wall mounted smoke detector guard or enclosure prevents looped items from being hung on the shield and the enclosure. The shield includes a mounting surface for mounting to a wall. A downwardly sloping surface structure extends from the mounting surface for extending above the top surface of the enclosure. The downwardly sloping surface structure has sufficient slope and length for preventing items from being hung on the shield and the enclosure while at the same time providing a direct smoke flow path therepast to the top surface of the enclosure.

Abstract: In a building fire alarm system, the light strobes of a network of strobes are synchronized to flash simultaneously. Each strobe has a charging circuit to charge a capacitor which discharges through a flash tube. Once a capacitor is charged, the charging circuit is disabled. A synchronization pulse is applied through common power lines to trigger discharge of each strobe capacitor through the flash tube followed by recharging of the capacitor.

Abstract: In a communication system such as a fire detection system, individual addressable devices determine their addresses from address interface modules at the device locations. An interface module includes wire connectors for receiving system wires and a device connector. The interface module also includes jumper wires which serve as a readable address identifier adapted to be programmed to an address with installation of the module and to be subsequently read by the addressable device.

Abstract: A smoke detection unit has a detection chamber for sampling smoke from a surrounding environment. The detection chamber allows air circulation but is optically opaque. This configuration is typical of photoelectric smoke detectors, for example. A housing defines a window though which air from the environment circulates into and out of the detection chamber. The window's height is approximately the same as the chamber. A cage vane is positioned in the window and is configured as an inverted frustoconical member. An inner edge of the cage vane is spaced away from the chamber. The angled vane, along the other aspects of the unit's configuration, improves sensitivity by increasing smoke circulation through the chamber. This configuration guides the air currents typically created by fires at the ceiling so that the smoke flows easily into the detection chamber.

Abstract: A smoke/fire detector assembly having a base section and a removable sensor section. The base section includes a plurality of electrical contacts and the sensor section includes a corresponding plurality of electrical contacts. Each one of the sensor section electrical contacts includes a member having a first end, extending from the sensor section, and a second end electrically connected to electrical components within the sensor section. Each one of the base section electrical contacts has: a first section having a surface adapted for mounting to a surface of the base section; a second section, having an edge common with the first section and a surface extending perpendicular to the surface of the first section; and, a pair of finger-like members, extending from a second edge of the second section. The second edge of the second section is perpendicular to the common edge. The finger-like members are laterally spaced along, and cantilevered from, the second edge of the second section.

Abstract: In a building fire alarm system, the light strobes of a network of strobes are synchronized to flash simultaneously. Each strobe has a charging circuit to charge a capacitor which discharges through a flash tube. Once a capacitor is charged, the charging circuit is disabled. A synchronization pulse is applied through common power lines to trigger discharge of each strobe capacitor through the flash tube followed by recharging of the capacitor.

Abstract: An electronic heat detector provides a fire alarm with a rapid rate of rise of temperature. The rate of rise indication is obtained from a comparison of outputs from a first temperature sensor which responds rapidly to environmental temperature, referenced to a second temperature sensor which has an intermediate response between that of the first sensor and an electronics board. The second sensor is positioned within a protuberance from the heat detector housing.

Abstract: A method and apparatus multiplexing multiple alarm and head type values in a peripheral fire alarm device includes a head component for sensing the presence or absence of smoke or heat and a base component for communicating with the control panel. A communication interface between the base and head components with no more than three connectors for multiplexing the values between the head component and the base component. The control panel stores algorithms particular to each type of head which may be used to determine if an alarm condition exists. Using data received from the peripheral fire alarm device, the control determines which type of head component is currently installed at the base component and selects the correct algorithm.

Abstract: Methods for detecting an alarm condition includes repeatedly converting an ambient condition into voltage outputs in detector apparatus repeatedly converting the voltage outputs into a series of actual analog values, polling the series of actual analog values to determine an average analog value, repeatedly comparing the difference between the average analog value and the last actual analog value with a predetermined delta-threshold value and indicating an alarm condition when the difference between the average analog value and the last actual analog value exceeds the delta-threshold value. Methods for detecting an alarm condition further includes repeatedly comparing the average analog value with a maintenance threshold value and indicating a maintenance signal when the average analog value exceeds the maintenance threshold value.