| 摘要 |
<p>1,134,059. Automatic control of speed. WOODWARD GOVERNOR CO. Dec.22, 1966 [Feb.1, 1966 (2)], No.57469/66. Heading G3R. The frequency of a first train of pulses is matched to that of a second train by a system in which logic circuitry detects the occurrence of two pulses in one train without an intervening pulse in the other train and produces a correcting pulse signal in an "increase" or "decrease" channel as appropriate. The pulses 49, 50 are produced by shaping the sinusoidal output of tachogenerators 42, 44 coupled to master and slave aircraft engines 20, 22, and are applied as set and reset signals to flip-flop 60 and to AND gates 62, 63. If the pulses occur alternately the AND inputs are never energized at the same time, but if, e.g., two pulses 49 occur in succession the second pulse finds the flip-flop still in its "set" condition so that AND 55 passes a signal which when amplified causes a stepping servomotor 39 to move one step. This would be in an increase direction and would rotate a nut 36 to shorten a throttle cable 28 controlling the slave engine 22. Two successive pulses 50 would similar cause a step in the decrease direction. To prevent constant alternate correction when the speeds are nearly equal the output of the AND gates may be connected to a similar flip-flop and AND gate arrangement so that correction is only made if the double pulse occurs on two consecutive occasions, thus creating a "dead band". Fig.8 (not shown). To prevent arbitrary correction if pulses in each train occur simultaneously they may first be applied as two inputs to an AND gate (80, Fig.8) which causes a one shot multi-vibrator (81) to produce an inhibiting pulse of finite length (t1) which prevents further AND gates (84, 85) from passing the pulse trains, which have been slightly delayed, to the flip-flop circuits. The servomotor may additionally receive signals from the system for keeping the relative phase of the signals constant which forms the basic subject matter of Specification 1,134,060.</p> |
