The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 1979
Filed:
May. 03, 1978
Kazuie Suzuki, Tokyo, JP;
Chuji Akiyama, Kawasaki, JP;
Hokushin Electric Works, Ltd., Tokyo, JP;
Abstract
An excitation system for a magnetic flowmeter provided with a flow tube through which the fluid to be metered is conducted, the tube having a pair of electrodes mounted at diametrically-opposed positions thereon and including an excitation coil to establish a magnetic field in the tube which is normal to the tube's axis and to a transverse axis passing through the electrodes, the fluid intersecting the magnetic field to induce a flow rate signal in said electrodes, the system including a full-wave rectifier coupled to a commercial power line source which produces sinusoidal a-c power whose wave periodically crosses a zero line. A switch is interposed between the rectifier and said excitation coil. Also provided are means to effect on-off control of the switch by high-frequency pulses which are in synchronism with the commercial power line frequency but are not generated in the region in which said a-c power crosses the zero line, whereby the full-wave rectified output is periodically fed to the excitation coil except in the interval when the a-c power crosses the zero line.