JPS5899625U - electromagnetic flow meter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

Fig. 1 is a circuit connection diagram of a conventional electromagnetic flowmeter, Fig. 2 is a circuit connection diagram of an electromagnetic flowmeter showing an embodiment of this invention, and Fig. 3 explains the operation of the electromagnetic flowmeter shown in Fig. 2. FIG. 2 is a diagram showing an excitation current waveform used for 11: Power transformer, 12: Rectifier circuit, 14: Excitation switching circuit, 15a, 15b: Excitation coil, 17
: Fluid tube, 18a-18b: Electrode, 19-21: Input
- Buffer amplifier, 20/22: Main amplifier, 23: Sampling circuit, 24/25: Analog/digital circuit, 26/29: Input/output port, 27: CPU. 28: Memory, 30: Digital-analog converter, 31
: Output buffer amplifier, 32: Constant voltage circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] An excitation power source that intermittently generates an excitation signal applies an excitation current to an excitation coil, and the excitation current applies a magnetic field to a fluid tube through which a fluid to be measured flows, and an electrode is provided in the fluid tube. An electromagnetic flowmeter that derives a signal corresponding to an amount of fluid obstruction, comprising means for deriving a signal corresponding to an excitation current of the excitation coil, and controlling a duty ratio of the excitation signal based on the signal from the derivation means. An electromagnetic flowmeter characterized by comprising a control means.