| 摘要 |
PURPOSE:To simplify the circuit and to improve the reliability, by obtaining differences between a speed reference signal and speed feedback signals from tachogenerators and turning off a motor when one of the absolute values of the differences is greater than a reference value. CONSTITUTION:If an antenna 3 is not normally driven, differences between a speed reference signal (a) and speed feedback signals f1 and f2 of tachogenerators 6 and 7 are caused in a failure detection circuit 21, the differences are obtained at adders 22 and 23, and after absolute values are taken at absolute value circuits 24 and 25, the values are compared with reference values h1 and h2 at comparators 28 and 29. If at least one of the absolute values of error signals d1 and d2 of the output of the adders 22 and 23 is larger than the reference signals h1 and h2, either one of relays 32 and 33 is operated with any output of the comparatos 28 and 29, resulting that a relay 34 is operative to open its contacts 34a and 34b and motors 4 and 5 are stopped. |
