Circuit for fire alarm apparatus controlled by gas-sensitive semiconductor sensors with low power consumption

摘要

1. A monitored circuit for detecting fire by a gas-sensitive semiconductor, with a low level of consumption, comprising on the one hand a semiconductor element (Rc1 ) with an electrical resistance varying with the nature and the amount of gas and fumes to which it is exposed, and on the other hand a heating filament (Rc2 ) for said element, characterised in that the semiconductor and its heating filament are connected in series whereby the same current passes therethrough.