A D-C Telemeter or D-C Selsyn for Aircraft

This paper describes a d-c telemeter which is particularly adapted for transmitting to the instrument board indications of pressure, temperature, liquid level and of the position of the various controlling members of the airplane. The description comprises the principle, variations, characteristics, and application of this telemetering system. Although the applications described are primarily in connection with aircraft, the versatile nature of this device makes it suitable for many other applications. The large number of indications which must be transmitted accurately to the instrument board of an airplane has created a demand for a telemetering system of small size and light weight. For many years the a-c Selsyn telemetering system has given excellent service in marine applications. Variations of this system are used successfully on aircraft. A search for a simpler and lighter system which will operate on direct current has led to the development of the d-c Selsyn telemetering system.