JPS554626A - Driving method of proportional controller - Google Patents

Abstract

PURPOSE: To reduce the cost of the driving method of a proportional controller by positively feeding an output signal back by applying an operation signal to the non- inversion input of a voltage comparator, and then by applying a voltage by the feed current of the proportional controller to the inversion input via a primary delay element.

CONSTITUTION: The output signal of present-value indication circuit 1 is compared with that of desired-value indication circuit 2 by differential differentiating circuit 8, differentiation is carried on until a difference between both the signals becomes zero, and the operation signal of the analog value of the differentiation result is applied to non-inversion input point (a) of voltage comparator 5. The output of circuit 2 is applied to point (a) via resistance 8 to limit the inferior of the output of circuit 3. The output of comparator 5, positively fed back to point (a) via resistances 16 and 6, drives transistor 10 to flow a feed current to solenods 11 of the proportional controller. A voltage at point (b) equivalent to this current is applied to inversion input point (c) of comparator 5 via primary delay elements 13 and 14. Consequently, comparator 5 outputs a driving signal of a string of pulses whose duty varies with the operation signal. Therefore, a triangle-wave voltage generator is unneeded and the cost can be reduced.

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