monitoring facility with veränderbarem ansprechschwellenwert for monitoring of physical quantities, in particular flammenwächter

摘要

The flame monitor surveillance equipment comprises two units. One (2) contains the sensor (9) and a sum-and-difference amplifier (11), the other the power supply connections (6) plus a two voltage level switch (7), and a warning light relay (8). The sensor, pref. a phototransistor or photodiode, forms one branch of a bridge circuit connected between supply (4) and earth (3). The amplifier is in parallel with the bridge. The latter has resistances (12, 12, 14) as the other branches. From the diagonal terminals, leads (15, 16) go to the amplifier input. the amplifier output (5) goes to the light relay (8). Alternatively, the sensor can be a photoconductive cell, with resistances and a Zener diode in parallel with it.