4325results about "Battery disconnect circuits" patented technology

A DC power source unit supplies a DC voltage to a power tool through an adapter when a power switch of the tool is turned ON and also charges a battery pack used as an alternative power source of the tool when the power tool is not operated. In order to prevent a rush current from flowing in a switch interposed between a switching power source circuit and the battery pack when charging the battery pack is commenced, the switch is rendered OFF when the output voltage from the switching power source is greater than the battery voltage. Charging the battery is started upon once lowering the output of the switching power source to a level lower than the battery voltage.

A power supply control device for controlling power supply to a pair of terminals to which a load is connected, comprising a voltage measuring part for measuring a voltage which has a predetermined relationship with the voltage of the pair of terminals, a short circuit detecting part for detecting whether a short circuit exists between the pair of terminals based on the measured voltage and for making power supply to the pair of terminals stop when existence of a short circuit is detected, and a constant current supplying part for supplying a constant current though the pair of terminals; wherein the short circuit detecting part is configured to detect that the previously detected short circuit is eliminated when the voltage measured by the voltage measuring part is equal to or greater than a predetermined threshold value upon supplying the constant current through the pair of terminals.

A protection of battery system having battery cells Cell1˜Cell3, FET switches SW1, SW2 that are connected to the high-side path and control on / off state of the path, as well as fuse F1 for cutting said path, primary protection circuits 31˜34 that detect abnormalities in charging / discharging of the battery cells and turn the FET switches off, and secondary protecting controller 38 that detect abnormalities in charging / discharging of the battery cells and controls the operation of fuse F1. Secondary protecting controller 38 controls fuse F1 if there is no tendency to a decrease in abnormalities after a prescribed period of time after control of the FET switch.

A method of conducting an operation including a battery. The battery includes a cell having a voltage. Power is transferable between the cell and the electrical device. A controller is operable to control a function of the battery pack. The controller is also operable with a voltage at least one of equal to and greater than an operating voltage threshold. The cell is operable to selectively supply voltage to the controller. The method includes the act of enabling the controller to operate when the voltage supplied by the cell is below the operating voltage threshold.

The method and system for managing power supplied from a charging circuit to a power source in an implantable medical device comprises the steps of and circuitry for: measuring the current drain of the medical device; measuring the elapsed time since the last full charge of a power source of the device; calculating the actual capacity of the power source (corrected for fade) based on the variable of current drain and the variable of elapsed time; calculating the operating time based on the variable of current drain and the variable of the actual capacity of the power source; measuring the voltage of the power source; signaling the medical device when the power source voltage has reached a certain low value which requires disconnection from the power source; disconnecting, during discharging, the power source from the medical device upon the power source reaching a certain low voltage in order to prevent deep discharging of the power source and subsequent damage; precisely limiting the charging voltage to the power source in order to prevent overcharging beyond safe limits; disconnecting, during charging, the power source from the charging circuit upon the power source reaching a certain high voltage in order to prevent overcharging of the power source and subsequent damage; sensing when the electromagnetic waves being transmitted by an RF transmitter / charger induce a voltage level above a certain value at an RF receiver of the implanted power management system; reconnecting power supply inputs of the medical device to the power source upon sensing this induced high voltage level; monitoring the temperature of the power source during charging and discharging; disconnecting the charging circuitry from the power source if the temperature of the power source raises above a certain level during charging; reconnecting the charging circuitry to the power source when the temperature of the power source drops below a certain low value during charging; disconnecting the implanted medical device from the power source if the temperature of the power source raises above a certain level during discharging; and, reconnecting the medical device to the power source when the temperature of the power source drops below a certain low value during discharging.

In a cordless power tool system, protection methods, circuits and devices are provided to protect against fault conditions within a battery pack that is operatively attached to a power tool or charger, so as to prevent internal or external damage to the battery pack or attached tool or charger. The exemplary methods, circuits and devices address fault conditions such as over-charge, over-discharge, over-current, over-temperature, etc.