基本信息
摘要：1,159,281. Differencing circuits. SOC. NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION. 4 Jan., 1967 [7 Jan., 1966], No. 503/67. Heading G4G. Apparatus for comparing two analog signals and selecting the greater comprises (Fig. 1), summing and differencing circuits, 1, 2 receiving input signals x, y after squarewave modulation by a reference signal e, and applying the difference signal (x-y) over parallel amplifiers 3, 4 of equal and opposite gains, to the controls of a switching relay 5 operated by a phase comparator 6 receiving the reference and difference signals. If (x-y) > 0, (x+y) and (x-y) are added at 7 to develop an output signal 2x and similarly if (x-y) < 0 they are subtracted to develop an output signal 2y, which may operate e.g. a bi-phase motor. Alternatively (Fig. 2, not shown) the input signals are modulated, and applied to a differential amplifier producing a signal representing (x-y), which is applied with the reference signal to a phase comparator producing a positive output for (x-y) > 0 and a negative for (x-y) < 0, and utilizing this to operate a trigger and gate selecting the appropriate modulated input signal x or y for (x-y)>0 or (x-y) < 0. The apparatus is applicable e.g. to gas turbine control systems utilizing more than one control parameter. The amplifier and switching may employ semi-conductors.
摘要附图：
