Abstract: In a flame detecting apparatus for detecting the flame of fire or the like using a sensor 1, a signal processing unit 3 includes a span counting section 5 for dividing a time base into several time spans, each having a predetermined time interval, and counting the number of signals output from the sensor 1 as a count value for each span, a count value storage section 6 for storing the count value for each span output from the span counting section 5, and an calculation section 7 for judging the occurrence of flame by taking into account the count values counted for the past spans which have been stored in the count value storage section 6, as well as the count value of the latest span, when the count value of the latest span is output from the span counting section 5.

Abstract: A central monitoring and alarming system for monitoring and alarming an abnormal condition, for example fire and gas leakage, includes a central monitoring station having a memory device and a signal processor, plural terminals returning information detected by sensors included therein and a supporting terminal unit for specifying a proper address assigned to the terminal units respectively so that an operator can reliably know an address without looking at an address setter disposed in a terminal unit.

Abstract: In a terminal device adapted to effect transmission and receipt of information through address polling by a central monitoring/control device, an address having a predetermined number of bits is preset in a first address setter, and an address comparator compares the address of a predetermined number of bits set in the first address setter with address data sent from the central monitoring/control device. As the result of this comparison, when the address of the predetermined number of bits set in the first address setter coincides with an address sent from the central monitoring/control device, the central monitoring/control device sends a new address, and this new address is set in a second address setter with respect to the terminal device whose address has coincided. Thus, after the new address is set in the second address setter of each of the terminal devices, the terminal devices are polled by the central monitoring/control device on the basis of these new addresses.

Abstract: An environmental abnormality alarm apparatus includes a sensor for detecting a fire, gas leakage, a burglar, or the like in a monitoring area, and a signal processor for receiving an output from the sensor and evaluating the output for an alarm determination reference and generating an alarm. A detecting unit is provided in the monitoring area of the sensor to detect a change in environmental condition resulting from objects or conditions other than those to be detected by the sensor, and an alarm determination reference is changed in accordance with an output state of the detecting unit during signal processing.

Abstract: A fire monitoring system used in a fire alarm arrangement includes a fire receiver and a plurality of fire sensors connected to signal/power supply zone lines from the fire receiver to a plurality of fire warning zones, the sensors for short-circuiting the respective zone lines with a low impedance in case of a fire. An analog detector having an address is located at a given warning zone among the fire warning zones. The analog detector is connected to the corresponding signal/power supply zone line through an analog sensor controller having an operation circuit for calculating an analog signal obtained by address polling from the analog detector.

Abstract: A device for generating an alarm signal in the event of an environmental abnormality has multiple sensors, with a multiplier associated with each sensor, an adder, and a comparator. The sensors are disposed in respective sensing volumes, which may be different. The sensors detect a level of smoke, heat, gas or other environmental abnormality within each sensing volume, and convert the level into an electrical analog signal. The associated multiplier multiplies a coefficient proportional to the sensing volume for the associated sensor with the analog signals from the sensor. The adder adds the outputs of the multipliers. The comparator generates an alarm signal at an output thereof when the output of the adder exceeds a predetermined value.

Abstract: A device for generating an alarm signal in the event of an abnormality in the environment of a detector includes a pair of signal/power supply lines, a number of detectors for detecting an abnormality, e.g., fire, gas leakage, or burglary, and an alarm receiver including a signal processing circuit for receiving a signal from a detector indicating the presence of an abnormality. The signal process circuit includes a signal storage circuit, and a converting circuit for changing one or a combination of at least two of a polarity, voltage, current, or impedance of a power source if the abnormality persists for a predetermined time. The change in the power source parameter is supplied via the supply lines to a signal holding circuit in the vicinity of the detector. The signal holding circuit is responsive to the changed parameter and changes state, thus providing an indication at the detector that the abnormality has persisted for the predetermined time.

Abstract: A fire alarm system has a main unit and a plurality of sensor terminals in accordance with a polling system. The plurality of sensor terminals are divided into a plurality of groups. When a given sensor terminal of a given group is accessed and transmits digital data as response data indicating a smoke concentration or a temperature to the main unit, and the response data exceeds a first reference value thereby indicating that a fire has broken out, the main unit accesses other sensor terminals of the given group. If some of the response data therefrom exceed a second reference value which is equal to or smaller than the first reference value, the main unit counts the number of such sensor terminals. When the number exceeds a predetermined number, the main unit displays information indicating the existence of a fire.

Abstract: A temperature sensor has a series circuit of resistors, a gain control switch connected in parallel with one of the resistors of the series circuit, and a reference voltage control switch connected in parallel with a middle resistor of resistors of a reference voltage generation section. The reference voltage and the gain of an operational amplifier are variable so as to change the resolution of the output signal and/or a detected temperature range of the sensor.

Abstract: A light transmission type smoke detector detecting smoke by sensing attenuation of light beam due to smoke is provided with a first voltage-holding circuit with a smaller time constant and a second voltage-holding circuit with a greater time constant both connected to a photoelectric transducer means; and an output from the photoelectric transducer means, which has sensed the light beam, charges the two voltage-holding circuits. When the photoelectric transducer means detects attenuation of the light beam by smoke, the first voltage-holding circuit holds the output voltage of the photoelectric transducer means for a relatively short time while the second voltage-holding circuit holds the output voltage for a relatively long time.

Abstract: An optical smoke detector having a light source and a light detector with the light detector shielded from direct light from the source. The light source is energized by a pulse generator and the outputs of the pulse generator and the light detector are fed through electric circuitry to produce one type of signal when the device operates normally and detects smoke and another type of signal should the detector fail to function in a normal manner.

Abstract: An ionization smoke detector having two ionization chambers with one of said chambers having an electrode at least partially surrounded by a conductive mesh constituting an intermediate electrode and the other of said chambers being formed between the intermediate electrode and an outer surrounding electrode of conductive mesh and a radioactive source carried by said outer electrode. The volume defined by the outer and intermediate electrodes is greater than the volume defined by the intermediate electrode.