| 摘要 |
<p>1280431 Ionization fire alarms NITTAN CO Ltd 10 July 1970 [12 July 1969] 33731/70 Heading G1N [Also in Division H1] In an ionization fire alarm, the F.E.T. 12 whose gate 14 is connected to the junction of a reference ionization chamber 2 and a measuring ionization chamber 4, is a junction type whose gate leakage current increases with temperature and which is located in thermal contact with the common electrode 43(25) in the open chamber 4. Thus, even when no smoke exists in the chamber 4, a rise in ambient temperature due to a fire increases the gate leakage current of F.E.T. 12 which has the effect of increasing the current flow through the chamber 2 and thus the potential at the junction of the two chambers, which causes energization of the alarm, Fig.1 (not shown).</p> |
