| 摘要 |
PURPOSE:To obtain a signal doubling device with high reliability for an automatic controller by supplying two signals showing the same contents to deliver them with priority in a normal mode and selecting one of both signals that has a smaller degree of variation when these signals are discordant with each other. CONSTITUTION:Two input signals V1 and V2 corresponding to the feefback value are supplied to a signal doubling device 11. These two signals are compared with each other by a signal comparator 1101. When the values of both signals are smaller than the set value alpha of a setter 1100, contacts 1101a and 1101b are opened and closed respectively. Then these input signals are delivered after their high values are selected by a high value priority device 1106. When the signal V1 has a fault and suddenly has the high value, the comparator 1101 works to close and open contacts 1101a and 1101b respectively. At the same time, a change factor signal comparator 1104 works to close a contact 1104a and set a brake 1107. Thus a contact 1107b1 opens to deliver the normal signal V2 via the device 1106. Then a contact 1107a closes and an alarm display signal is delivered. |
