| 摘要 |
PURPOSE:To reduce the power consumption by eliminating exciting current as soon as it exceeds a level so set that the magnetic circuit fails to attain a magnetic saturation in each polarity each time the exciting current increases. CONSTITUTION:An electromagnetic flowmeter sets the exciting current at such values (-I0) and (I0) that any magnetic saturation fails to be attained. As shown by the broken line (OBC), the saturation value of the exciting current in each polarity is fixed at a value exceeding the set current values (-I0) and (I0). The exciting current is always compared with the set current values when it is increasing and eliminated as shown by the broken line (BB') as soon as they are exceeded. This can shorten the time (t) of continuously running the exciting current thereby reducing the power consumption. |
