Critical field resistance
Introduction '''Critical field resistance''' is a term that is associated with a shunt DC generator. In a DC shunt generator, the voltage induced across the armature, '''Va''', is directly proportional to the flux acting across it, The flux in a DC generator is directly proportional to the field current, '''If'''. The critical field resistance is defined as the maximum field circuit resistance (for a given speed) with which the shunt generator would just excite. The shunt generator will build up voltage only if field circuit resistance is less than critical field resistance.It is a tangent to the open-circuit characteristics of the generator (at a given speed).
References * Electrical Technology - II by B.L. Thereja
External links * DC Machines