| 摘要 |
1311948 Control systems for inductive loads ALLMANNA SVENSKA ELEKTRISKA AB 28 Aug 1970 [1 Sept 1969] 41505/70 Heading H2H [Also in Division H3] In a system in which D.C. to a load 9 is regulated by a thyristor 1 which is turned off by an auxiliary thyristor 3 in an oscillatory circuit comprising an inductor 5 and a capacitor 6, the inductor is common to the load circuit and to the oscillatory circuit, and the two thyristors and the capacitor are in parallel with each other and in series with the load. 1 and 3 are triggered alternately by adjustable means 11 so as to regulate the average current in the load. Initially, the upper plate of 6 is positive, but the charge reverses via 5 and 3 when 3 is triggered, turning off 1. This charge is dissipated through the load and recharging occurs with the original polarity ready for the reset operation. 2 is a "flywheel" diode for the load. A resistor 7 and diode 8 may be provided to maintain "overcharge" of the capacitor 6 resulting from any inductance in the supply conductors. In Fig. 2 (not shown) the thyristors 1 and 3 are each replaced by a parallel pair and the inductor has four close coupled windings, one in series with each thyristor. |
