Low power indication circuit for lead acid battery pack
US6313611A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 2000 |
| Grant date | Nov 6, 2001 |
| Priority date | — |
| Expiry date | May 24, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A lead-acid battery pack has an electronically-controlled power switch connected in series with the battery. A voltage monitor/controller is connected in series with a normally-open ON/OFF switch across the battery, the controller controlling a ramped pulse width modulator which provides a switch control signal to the power switch. The controller is program controlled so that, a fraction of a second after the ON/OFF switch is closed, the modulator will provide a constant DC level control signal to the power switch to hold it closed. If the battery voltage drops below a first level for several seconds, the modulator will produce a PWM switch control signal of gradually decreasing pulse width and duty cycle until the power switch is permanently open. This gradual decrease of power delivered from the battery will occur immediately upon the battery voltage dropping below a second level lower than the first level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.