1. Field of the Invention
The invention relates to a fire detector.
2. Description of the Prior Art
Numerous types of fire detectors or alarms exist, such as temperature rise detectors generally comprising thermistors, detectors of radiation emitted by a flame and including photoelectric cells or a brush discharge tube and smoke or combustion gas detectors. The latter are based on optical phenomena or even include at least one ionization chamber traversed by a current which varies according to the gases passing through it.
All these devices are connected electrically to a warning or alarm system controlled by a device which establishes the difference between a measured value and a reference value corresponding to a normal or tolerable level. These devices generally require a considerable consumption of current which is particularly heavy considering that they operate continuously. In addition, they are sensitive to disturbing external phenomena and use, for the ionization detectors, considerable radioactive sources.
It is an object of the invention to provide a particularly reliable and low comsumption electronic system for fire detection purposes. This is based on a comparative measurement between a measured value and a reference value.
It is another object of the invention to provide a warning system in the case of faulty operation of the fire detection device.
Other objects and advantages of the fire detector system according to the invention will be understood on reading the description which follows.