| 摘要 |
1,011,488. Measuring speed electrically. STANDARD TELEPHONES & CABLES Ltd. June 6, 1963, No. 22536/63. Heading G1N. An alarm circuit to indicate when the rate of descent of an aircraft exceeds the safe value established by a predetermined linear relationship between altitude and rate of descent comprises a network 21 (Fig. 3) fed with an altitude signal from 20, an altitude rate of change signal from 23, and a constant voltage from 24, in such proportions as to give a negative output when the rate of descent exceeds the safe value. The output signal is processed through a chopper circuit 25 coupled to a multivibrator 26, a limiting amplifier 27, a D.C. restorer 28, and an averaging circuit 29, to give a resultant D.C. voltage of a higher value when the mode of descent is safe, and a lower value when the rate of descent exceeds the safe value, to actuate an alarm circuit 30. An overriding alarm indication is produced directly via lead 31 when the altitude signal at 20 indicates less than 150 feet. |
