System for conserving battery life in a battery operated device

US7739529B2 · kind B2 · utility

Assignee

• Bridgestone Americas Tire Operations, LLC · US

Inventors

• Gordon E. Hardman · Boulder, US
• John W. Pyne · Erie, US
• Molly A. Hardman · Boulder, US
• David A. Przygocki · Longmont, US
• David M. Coombs · Manassas Park, US
• Paul B. Wilson · Murfreesboro, US
• Ronald C. Grush · Longmont, US
• Philip B. Loudin · Boulder, US
• Brett W. Floyd · Longmont, US

Key dates

• Filing date: Nov 29, 2006
• Grant date: Jun 15, 2010
• Expiry date: Aug 9, 2028

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29D2030/0072
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A system for conserving battery life in a battery operated device such as a tire tag where there are several modes of operation. The typical mode is the deep sleep mode where the tag is generally inactive (no clock is running; however, an RC watchdog timer is running, which uses very little power). The tag spends most of its time in this low power mode. The tag periodically partially awakens to a lucid sleep mode (when the watchdog timer times out), initiates a low-speed clock, determines if it is time to enter a search mode by examining a search mode counter and, if it is not time, adjusts the search mode counter (e.g., decrements the counter by one), and returns to the deep sleep mode. The tag sleeps in the deep sleep mode most of its life in an effort to conserve battery power. During the deep sleep mode, because the clock oscillators are OFF, a deep sleep counter is adjusted (incremented or decremented) periodically (e.g., about every 18 ms) by an internal R/C oscillator. The internal watchdog timer (WDT) monitors the deep sleep counter and when the deep sleep counter, for example, contains a NULL value (all zeroes) the WDT wakes up the microcontroller (i.e., the WDT initiates …