Speed and voltage regulation of d.c. shunt machines using power transistor in field circuit

A simple method for speed and voltage regulation of d.c. shunt machines is presented. The method is based on the use of a power transistor circuit which automatically adjusts the field current Such that the Speed or output voltage, as the case may be, is maintained constant with increasing load on the machine. An added advantage of this inothod is that, by the simple adjustment of circuit parameters, the characteristics of a compound generator can be achieved from a shunt generator without using a series field winding. Experimental results prove the effectiveness of the method.