摘要 |
663,380. Electromagnetic relays. DREYFUS, J. A. Jan. 26, 1949. No. 2206/49. Class 38 (v). [Also in Group XXXVIII] An electro-magnetic differential relay comprises a twowinding coil 8 suspended in the air gap of a permanent magnet 9 by a system of blade springs 10. Thus, depending on the relative strength of the currents in the windings 8, contacts 11, 12 or 13, 14 will be closed. |