Improvements in or relating to range-finding apparatus

Abstract

Abstract 218,548. Pollak, J. E., (Maschinenbau- Akt.-Ges. Seebach). Nov. 12, 1923. Range-finders. - Electrical resistances are utilized in conjunction with telescopes at the ends of a known base to determine the range of a distant object by the solution of the equation log. distance = log. base + log sin. of the angle opposite the distance to be measured + log. cosec. of the angle opposite to the base. On the axes of the telescopes 1, 2 are mounted resistances 5 provided with contacts 6 arranged so that the resistance in the circuit is proportional to the angles a b respectively. An intermediate instrument Z comprises a similar resistance which is adjusted in conjunction with the resistances 5 so that balance is obtained on a Wheatstone bridge comprising a galvanometer G and a resistance V corresponding to 180‹. On the same axis as the resistance 8 is a resistance 9 corresponding to the valves of cosec c. This resistance 9 is in series with a resistance 20, representing log sin b and a resistance 21, being log. of base. The total resistance is measured on the ohm-meter J graduated in yards, giving the distance required. A modification is described in which the sum of the angles a b is balanced on a Wheatstone bridge against a resistance proportional to cosec. (a + b) utilized in a manner similar to that described above.

Inventors

No inventors recorded.

Bibliographic Details