Telxon Corporation

Symbol Technologies, LLC

Martin M Weiss

Lee E Leppo

Prashant A Solanki

A Universal Serial Bus (USB) remote hub or function device is provided that includes a large energy well (e.g. rechargeable device such as a battery or large capacitor) for providing the required power to peripherals when the peripheral device requires more power than the USB allows. The large energy well or rechargeable device shall charge using current drawn from the USB bus and terminate charge by the controller or discrete circuitry provided on the remote hub or function. The rechargeable device shall draw current from the USB at a maximum of 100 ma during power up and may enter a high power bus powered mode, so that it can draw the maximum 500 ma of current provided by the USB. The rechargeable device will turn off or draw a sleep current of less than 500 pa when the USB is placed in a suspend state. The device may optionally be configured to provide remote wake up functionality to provided support to the USB power management to allow recharging to resume.

Method and apparatus for charging a self powered USB device at different charge rates according to the charge level of a rechargeable element on the device

A power distribution system is provided for distributing power in a portable device being coupable to a charging system and including a main battery power and a bridge battery power. The charging system is coupled to a power bus through a diode. The main battery power system and the bridge battery system are also both coupled to the power bus through diodes. The predetermined voltage level is set with respect to the charging system, the main battery and the bridge battery, such that if all three are coupled to the bus, the recharging system both powers the unit and recharges the main battery. If the recharging system is removed, the main battery power system powers the portable device, and if the main battery power system is removed the bridge battery will provide power to the portable device. The distribution system also includes a monitoring system for measuring the predetermined charge level on the battery and disabling a FET switch, so that the main battery stops charging to protect the main battery against overcharging. A monitoring system is also provided for monitoring the voltage level of the main battery utilizing a comparator system.

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The Woodlands, TX, United States of America

Martin M Weiss