Power efficiency circuit

US6680690B1 · kind B1 · utility

Assignee

• Saab Marine Electronics AB · SE

Inventors

• Valter Nilsson · Skintebo, SE
• Pär Abrahamsson · Linköping, SE

Key dates

• Filing date: Feb 28, 2003
• Grant date: Jan 20, 2004
• Expiry date: Feb 28, 2023

Classification

• Technology area (CPC G): Physics
• CPC primary: G01F23/284
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A radar level gauge for measuring a level of a surface of a product in a tank having a two-wire process control loop, output circuitry coupled to the two-wire process control loop for setting in the loop a desired value of a loop current (Iloop) corresponding to the product level, a power supply circuitry coupled to the two-wire process control loop for receiving power from the loop and being a source of power for a microwave source, a microwave receiver, a measurement circuitry and the output circuitry and including a converter for transferring power from the loop to said power supply circuitry by means of feeding a first current (IDC/DC) from the loop to the power supply circuitry, a current generator included in said output circuitry for generating in parallel to said first current a second current (Ish) in the loop for maintaining said loop current at a value corresponding to said product level and a sensing circuit for determining the value of said second current and having an output indicative of the value of said second current.