| 摘要 |
<p>538,303. Control of A.C. and D.C. motors. KRAMOLIN, L. L. DE. July 7, 1939, No. 19883. Convention date, July 9, 1938. Drawings to Specification. [Class 38 (iii)] [Also in Group XXXV] In a system in which a high speed prime mover is coupled to a high frequency generator, for example of Goldschmidt type and supplies a D.C. motor or motors through a rectifier speed control is obtained by selective control of the frequency of the generator output, e.g. by tuned circuits controlled by variable saturation of magnetic cores, by amplitude control, e.g. by slight variation of the prime mover speed to alter the resonant condition of a high frequency circuit or by detuning tuned circuits, and by phase control, e.g. of the grid potential of a rectifying tube. By modulating the high frequency current a sinusoidal A.C. output may be obtained from the rectifiers and A.C. motors may be controlled by changing the modulating frequency, e.g. by adjustment of a condenser in the grid circuit of a low frequency valve oscillator providing modulating current to a generator winding or a portion of the high frequency circuit. The system may be applied to locomotive vehicles and a train may be controlled from any position thereon by a continuous circuit carrying magnetizing current for varying inductances in tuned circuits. Specification 195,049, [Class 38 (iv)], is referred to.</p> |
