| 摘要 |
PURPOSE:To obtain an autotransformer which has great resistance against instantaneous overload using autotransformer and a brush on the market by providing a balancing coil connected to winding terminals with plural brush electric potentials and by connecting the balancing potential of the balancing coil to the third terminal. CONSTITUTION:Input voltage Ei is applied between the first and the second terminals. If voltage induced in a winding 4 at the contact point of a brush 5a is assumed to be EA and voltage induced in the winding 4 at the contact point of a brush 5b is assumed to be EB, the voltage at the middle tap of a balancing coil 6, i.e., output voltage EO becomes (EA+EB)/2 since the ratio of winding number divided by the middle tap of the balancing coil 6 is 1:1. A circulating current due to the difference of the voltage EA and EB is also limited by the impedance of the balancing coil 6. The contact positions between the winding 4 and the brushes 5a and 5b are shifted by the rotation of a shaft 10 and the output voltage EO is set at a required value. |
