| 摘要 |
1,005,431. Phase shifting; automatic voltage control. DE HAVILLAND AIRCRAFT CO. Ltd. Oct. 24, 1961 [Oct. 24, 1960], No. 36484/ 60. Heading H2F. [Also in Division G3] A device for changing the phase of a square waveform E u comprises means for applying said waveform E u across a load and means operable to supply across said load, for a period of time commencing at the beginning of or terminating at the end of each half cycle, a waveform- 2E u such as to produce a waveform Ep with the desired phase shift. In the embodiment described one secondary winding 7 of a transformer 4 produces a reference voltage e 1 = ¢E 2 across a load resistor R L which forms, with the resistor R s , a potential divider, and a magnetic amplifier M.A. acts as a switch to supply across the load R, either the voltage E 1 or O as its impedance is effectively O or infinite. For a non-variable phase-shift, a saturable reactor may replace the magnetic amplifier. Other switching devices, e.g. transistors, S.C.R's valves, thyratrons and switches may be used to replace the magnetic amplifier. |
