摘要 |
In a method of controlling the rate of flow of a fluid by using an electromagnetic flow control valve of the on-off functioning type and by operating this valve with a pulse signal of which duty is regulated, the flow rate is minimized or maximized by making the duty of the pulse signal slightly greater than 0%, e.g. 2%, or slightly smaller than 100%, e.g. 98%, instead of making it 0% or 100% as in conventional control methods. A principal advantage of such shifting of the minimum and maximum duty values respectively from 0% and 100% is the possibility of easily discriminating a failure, for example, in the supply of the pulse signal from proper minimization or maximization of the duty of the pulse signal.
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