GB550144A - Improvements in and relating to electric dynamometers - Google Patents

Abstract

550,144. Rotary-absorption dynamometers. BRITISH THOMSON-HOUSTON CO., Ltd. July 28, 1941, No. 9579. Convention date, July 26, 1940. [Class 106 (ii)] Comprises electric apparatus for testing prime movers having field-producing means and a rotary element for placing a load of controllable speedtorque characteristic on the prime-mover, in which field fluxes in the same direction are produced by independent voltage sources one of which is constant and the other variable with the speed of the dynamometer, means being operable to alter both voltages simultaneously. In Fig. 1, the prime mover 11 is connected by a shaft 13 to the rotor 14 of a dynamometer 15 of the inductor eddy-current type. The shaft 13 is also connected to the armature 16 of a direct-current dynamo 17 which supplies current to the field 18 of the dynamometer the field 18 being connected to a potentiometer 19 connected to a supply source 20. An adjustable tap 21 furnishes a coarse adjustment and a variable resistance 22 a fine adjustment for the field 18. The booster exciter 17 has a field 23 furnished with an adjustable tap 25 moving over a potentiometer 24 and is connected in parallel with the armature 16 through a field-reversing switch 26. In a modification the field winding 18 is in two sections, a double-pole switch serving to connect them in parallel with one another across the mains or one across the main and the other in series with the armature 16. Specification 524,080 is referred to.