| 摘要 |
<p>PURPOSE:To improve the efficiency of a distance measurement by comparing AGC voltages of a 1st and a 2nd AGC circuit when an intense signal arrives suddenly in a no-signal state. CONSTITUTION:When the intense signal arrives suddenly in the no-signal state, the AGC voltages of the 1st and 2nd AGC circuits 3 and 4 are compared with each other and the numbers of pulses from 1st and 2nd detectors 5 and 9 are compared with each other. Consequently, when it is decided that a 1st receiver 1 is abnormal, a connection with the 2nd receiver 7 is made by switching. Further, if the intense signal arrives suddenly in the no-signal state, outputs of a 3rd AGC circuit 23 and a 4th AGC circuit 24 and the output of a pulse quantity detecting circuit are compared. Consequently, one proper circuit between the 3rd and 4th AGC circuits 23 and 24 is selected to control the gain of the receiver.</p> |
