摘要 |
901,781. Amplifiers. CANADIAN WESTINGHOUSE CO. Ltd. Sept. 11, 1959 [Nov. 5, 1958], No. 31019/59. Class 40 (9). An amplifier or generator comprises an alternating current generator with a toothed rotor 4 and a reactor 3 excited by the signal from source 1. The output from the reactor 3 is rectified by a rotary switch 6 running in synchronism with the rotor 4, the rectified output being fed to terminals 12, 13. Filters 2 and 5, respectively, pass and reject the frequency of the signal from 1. In a modification, Fig. 1A, transistors are used instead of a mechanical switch. A signal applied to terminals 14 controls the output of the centre-tapped winding 18 of alternator 15. Alternator 24, which is mechanically linked to alternator 15, is excited by winding 26 and controls transistors 19 to 22 in series with secondary windings 28 to 31 to give full-wave rectification. The output is fed to the load 33. A voltage reference 34, Fig. 4, may feed the generator 36 through a variablegain amplifier 35. A feed-back may be taken from the input to the load 37. The feed-back is compared with the voltage reference 34 in a comparator 39, the amplifier 35 being controlled thereby to correct any error. To give a smooth output, two amplifier generators of the kind shown in Fig. 1a may be connected with their outputs in series and 90 degrees out of phase. |