摘要 |
The invention relates to a digital control device for an inverse rectifier having controllable switching elements for driving an A.C. motor operable at a variable frequency. The device has a pulse generator for producing timing pulses at a multiple of the frequency of the inverse rectifier frequency and a location counter 26 controlled by the timing pulses. A control store in the form of a ROM has at least two storage zones occupied by different controlling tables of which the data characterizes the periodically changing signal pattern for the ignition and extinction signals of the controlled switching elements of the inverse rectifier. A table selecting apparatus which, depending on setting and operating parameters, delivers a preparatory selecting signal for the desired control table and, after a change in this selecting signal, appropriately switches the storage zone over.
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