OPEN LOOP INDUCTOR CURRENT CONTROL SYSTEM AND METHOD

• US 20040027097A1
• Filed: 08/09/2002
• Published: 02/12/2004
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: DeNicholas, Joseph, Gray, Randall C.
• Granted Patent: US 6,690,144 B1
• Time in Patent Office: Days
• US Class Current: 323/222
• CPC Class Codes: G05F 1/10 Regulating voltage or current G05F1/02 takes precedence; for electric railways B60M3/02

Abstract

An open loop current control system for regulating the flow of electrical current in an inductor that utilizes two methods of monitoring the current flow in the inductor. The open loop control system maintains the level of current in the inductor between two boundary levels by switching a boost transistor between an on and an off position based upon the level of current in the inductor. The control system measures the level of current in the inductor when a boost transistor is turned on. When the boost transistor is turned off, the control system determines the time period that is required for the current in the inductor to decay from the upper boundary level to the lower boundary level based upon the measured voltage difference across the inductor.

Claims