| 摘要 |
1,175,431. Automatic voltage control. ROBERT BOSCH G.m.b.H. Feb.23, 1967 [Feb. 25, 1966], No.8672/67. Heading G3R. A voltage regulator for a multi-phase generator 10 having a rectified output on lines 13, 14 and including a field winding connected to successive output phase windings 1, 2 by way of respective thyristors 17, 18, is adapted to supply firing pulses to the control electrodes of the thyristors, the pulses being synchronized with the frequency of the generator and their magnitude and phase relationship relative to the half cycles of applied field voltage being dependent upon the voltage of the phase 3 preceding phases 1 and 2 and upon a direct voltage representative of output voltage variations. Thus the phase voltage of winding 3 is superposed, by way of resistor 53, diode 52 and resistor 35, on the voltage UR appearing across resistor 42, the resultant voltage US being applied to transistor 26 which has its emitter connected to a reference voltage UZ derived from Zener diode 28. The voltage UR is proportional to output voltage variations and is derived from a comparator including a voltage divider 47, 48, 49 connected across the output lines 13 and 14, a reference Zener diode 43 and a transistor 39. The arrangement is such that when the output voltage is below a predetermined value the resultant voltage US is less than the voltage UZ and transistor 26 is conductive; a firing potential is thus applied to the control electrodes of thyristors 17, 18 which conduct to pass full excitation current. As the output voltage builds up, the voltage UR increases and the conduction of transistor 26 is controlled in such a manner Figs. 2 and 3 (not shown) that the thyristors 17, 18 are fired at a point in the half-cycle of applied voltage dependent upon the magnitude of voltage UR. The field current is thus automatically controlled at a value sufficient to maintain the output voltage on lines 13, 14 at the predetermined value. |
