Circuit and method of operation for an adaptive charge rate power supply
US6833686B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 2003 |
| Grant date | Dec 21, 2004 |
| Priority date | — |
| Expiry date | Feb 21, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J2207/40
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A convenient source of charging power for portable communication devices is an integral power node of a computer data bus, such as a USB (universal serial bus) port. Unfortunately, USB ports have limited power capacity, making them generally incompatible with battery charge controllers (BCCs) which are designed to receive a steady, high capacity input. The invention provides a battery charging circuit which adjusts to the parameters of an external power supply such as a USB port by adding a regulating circuit to a standard BCC design. This regulating circuit maximizes the current drawn by the BCC, while keeping the voltage to the BCC above a preset minimum (the low voltage shut off level for the BCC). If the voltage to the BCC begins to drop, the regulating circuit reduces the current drawn, so the voltage rises and stays within the operating range of the BCC.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.