adjusting device for rolling mill rolls.

摘要

583,851. Gas burners. HONEYWELL-BROWN, Ltd. July 23, 1943, No. 11976. Convention date, July 11, 1942. [Class 75 (i)] [Also in Group XL] A flame-detecting circuit comprises a thermionic tube T2 having its anode supplied by one section 16 of a transformer and having its grid biassed in accordance with the potential of a condenser 49 which is charged in one direction by the grid current of a second tube T1 derived from a second section of the transformer and in the opposite direction from a third section of the transformer acting in conjunction with the rectifying action of the flame 68 or of a photoelectric cell acted on by the flame. When the flame (e.g., the flame of a pilot burner) is out the charge on 49 biasses tube T2 to cut-off and relay 22 remains de-energized and prevents ,the operation of the main burner. When the flame is present relay 22 is able to operate. If, when the flame is absent, the gap becomes bridged by a non-rectifying impedance, the tube T2 is given an alternating bias which, since it is in opposite phase to the anode supply, prevents the operation of 22. The anode circuit of the second tube T1 tends to ensure this @pl.ase relationship when the shunt is of low impedance and also acts as a rectifying circuit, the voltage developed across resistance 60 then tending to bias T2 to cut-off.