| 摘要 |
537,694. Oscillation generators. KING, A. J., ARMOUR, A. M., and METROPOLITANVICKERS ELECTRICAL CO., Ltd. Jan. 1, 1940, No. 58. [Class 40 (v)] [Also in Group XXXV] In order to produce alternating-current of low frequency, such for instance as is utilized in the demagnetizing process described in Specification 537,693, [Group XXXV], a condenser is connected in series with the field-windings of a direct-current generator of the short-field type. The figure shows such a generator 1 with a condenser 3 in series with the full-winding 2. The condenser 3 is bridged by a rheostat 5 and switch 4. By closing the switch and giving the resistance 4 a low value the generator 1 gives direct current, but if the switch is opened it gives an alternating current. If the switch 4 is closed and the resistance 5 increased the direct current first diminishes and then, when the resistance 5 reaches a certain value, changes to an alternating currect of about half the frequency of that given on opening the switch 4 ; as the resistance 8 is further increased the frequency increases. Means may be provided for re-exciting the generator if it stops in a non-magnetic state. Such a generator may be coupled directly to the load or used as an exciter for a second generator 9 as shown. |
