Abstract :
FOR many years during the initial use of the carbon-pile regulator for control of aircraft generator systems, the adjustment of the regulator was considered to be extremely difficult. This is no longer true. Because of the instability of early regulator designs, there was no attempt to adjust the regulator at its theoretically optimum adjustment point. This was brought out in previous papers1¿3 on the carbon-pile regulator which cover its construction, component characteristics, principles of operation, and adjustment. References to adjustment procedures have generally pointed out that the system would become unstable over a large portion of the adjustment range and that this region must be avoided. The result was that the instructions given for locating the stack screw adjustment point were by trial and error in the narrow region of stability. Fig. 1 shows the relation between the stable region of early regulator designs and the optimum adjustment point. At the time this was the only method but, in the design in Fig. 2, the instability during adjustment no longer exists because of the addition of a mechanical damping feature4 and an electric stabilizing circuit; see Fig. 3(A). With the stability problem solved, the adjustment procedure may be reconsidered. It is the purpose of this paper to show that the original adjustment procedure by the cut and try method can be replaced by a more direct method. It will be shown that the theoretically optimum adjustment point falls at a specific point on the adjustment curve. In accomplishing this, it will be pointed out that the electromagnet core position, also previously located by a trial and error method, may be correctly located during assembly when an armature calibration measurement is made.
