| 摘要 |
1,174,813. Automatic voltage control. ROBERT BOSCH G.m.b.H. Feb.10, 1967 [Feb.12, 1966], No.6458/67. Heading G3R. A voltage regulator for a multi-phase generator 10 having a rectified output on leads 13, 14 comprises thyristors 20, 21 connected to supply the generator field winding 19 from two phase windings S, T of the generator; a comparator 35 which supplies an output voltage proportional to the deviation in the output voltage on lines 13, 14 from a reference voltage defined by a Zener diode 37; a saw-tooth generator including a capacitor 52, a transistor 53 and a resistor 55 which produces an output synchronized to the frequency of the generator 10; and a control switch constituted by a transistor 63 to the base of which is applied a resultant signal formed by superposing the voltage from comparator 35 on the said saw-tooth voltage, the output from this switch being connected over a further transistor 66 to the control electrodes of the thyristors 20, 21. In operation, with the output voltage of the generator below a desired value the resultant signal applied to transistor 63 is such that this transistor and transistor 66 are non-conductive and the potential at the control electrodes of thyristors 20, 21 is sufficient to fire the thyristors, this potential being derived from a voltage divider 69, 70 connected across the output leads 13, 14, and thus a high excitation current flows in the field winding 19. If the output voltage then builds up beyond the predetermined value the resultant signal applied to transistor 63 is such that the transistor 63 and transistor 66 are rendered conductive at a time in the half cycle of applied field voltage dependent upon the variations in the output voltage, the resultant signal being in the form of pulses having a width proportional to said variations, Figs.2 and 3 (not shown) whereby resistor 70 is short-circuited to remove the firing signal from the thyristors 20, 21. Thus, the thyristors 20, 21 operate with phase-angle control to regulate the field current at a value such that the output voltage is maintained constant. A further embodiment, with a modified saw-tooth generator circuit, is described with reference to Figs.4 to 6 (not shown). |
