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:
Dec. 04, 1990
Filed:
Aug. 07, 1989
Gary K Baird, Richmond, TX (US);
Halliburton Logging Services, Inc., Houston, TX (US);
Abstract
A logging tool motor controller inverter and feedback loop control system is set forth. A conductor is extended along the logging cable to provide electrical power at a frequency and voltage determined at the surface. In the logging tool, a rectifier connected to the conductor 40 form a DC current applied to three DC switches which operate in timed sequence to provide multiphase switched DC for operation of the motor. A feedback loop includes an instantaneous measuring wattmeter for determining power consumption of the motor, a variable frequency oscillator which is driven thereby between upper and lower frequency limits, and a multiphase controller connected to the variable frequency oscillator for timely switching the DC switches delivering power to the motor.