MONITORING EQUIPMENT FOR PRECISE APPROACHING COURSE INDICATOR

摘要

PURPOSE:To easily but certainly discriminate the propriety of the angle of elevation of a lamp indicating the angle of approach of an aircraft when the angle of elevation is detected by arranging four or more light receiving windows at different elevations and logically discriminating the light receiving signal outputting levels of the windows. CONSTITUTION:The light L1 of the lamp A is received at the reference position (a) of a photoreceptor, light receiving windows 111 and 112 and 113 and 114 respectively receive white and red light rays. Therefore, both light receiving signal outputs V1 and V2 of photoreceptor systems 121 and 122 respectively provided to the windows 111 and 112 are at 'H' levels. On the contrary, the light receiving signal outputs V3 and V4 of photoreceptor systems 123 and 124 respectively provided to the windows 113 and 114 are at 'L' levels. Since the outputs V1 and V2 are almost the same in level, the output VP10 of a comparator 211 is at an 'L' level and its inverted signal VP01 become high in level. Moreover, the comparing output V20 of the outputs V2 and V3 becomes 'H' in level and, since the outputs V3 and V4 are almost the same in level, their comparing output P30 is at an 'L' level. As a result, its inverted signal V03 is 'H' in level. Therefore, an AND gate 22 is established and a discriminating output can be obtained to the angle of elevation.