Digital controller for multiphase thyristor chopper - has clock pulse counter connected via decoder to thyristors and shifted pulse train decoders also receiving output from reverse counter

摘要

The chopper control is for use with machines fed in parallel from a common d.c. source e.g. in electric vehicles. The digital control is intended to ensure that all choppers do not switch on at the same instant. Timing pulses are generated and fed to a counter which transmits them to a non-delayed pulse decoder for triggering the choppers (8, 9, 10, 11) is sequence. The pulses are also fed to time delayed pulse decoders which trigger the commutating circuits. An up-down counter system provides the second input to the delayed decoders to set the commutating point. Diode matrices are used to form delay circuits.