Aiming for the issue of electromagnetic flow meter s accuracy, the author assays and compares advantages and defects of exciting mode on the grouds of circuit theory expounding a project of regular carrent intermittent square wave exciting, which could improve accuracy and detract power waste of apparatus.

In order to solve those problems,this paper presents a signal conditioning method with the averaged value of the first harmonic and proposes an intermitted exciting mode.

It is mainly composed of three parts: transducer, alarm device and magnetic field exciter.

In the IF transformer,the measure of improving exciting current was taken,and higher velocity of dragging charge from parallel capacitor when light loaded or no loaded was achieved to meet the condit.

This paper analyzes the forming process of unloading voltage and the relations among unloading voltage, phase electromotive force, exciting current and rotational speed in an alternator.

This paper makes a quantitative analysis of the transient state of output voltage and exciting current in an alternator, gives the expressions of output voltage and exciting current in no-load and load conditions, and deduces the calculating formulas of cut-off time and turn-on time of the power transistor in an electronic voltage regulator.

This paper discusses the excited magnetic frequency of an inouctive synchronous apparatus under working conditions within the aplitude range,the feeding rate of the working platform, the resolving rate of displacement measurement, the measurement accuracy, and theirrelationship.