BRANDAL ARRANGEMENTS WORKING WITH JONISATION

摘要

In the case of an ionisation fire detector having a measuring chamber (10), a reference chamber (12) connected in series with the latter, a first electronic circuit element (40) connected to the connecting point of the said reference chamber, a second electronic circuit element (50) connected downstream of the said first element, and a feedback resistor (30), the feedback resistor (30) lies between the reference chamber (12) and the detector terminal (32) connected to the latter. The main current route (E-C) of the second electronic circuit element (50) lies in a current path (E-C, 52, 36; E-C, 36) parallel to the feedback resistor (30). Such a fire detector can be produced with small dimensions, since the circuit elements can, at least for the most part, be fabricated using integrated circuit technology. IMAGE