Abstract: An apparatus and a method to charge a battery, the battery charging apparatus including: a battery unit which is chargeable; a battery charging unit which charges the battery unit; and a controller which adjusts a preset charge voltage of the battery unit based on a charge allowance capacity of the battery unit to have a predetermined value, and controls the battery charging unit to output the adjusted charge voltage and to charge the battery unit. Accordingly, the apparatus and method are capable of charging a battery based on a charge allowance capacity decreased owing to deterioration of the battery to safely use the battery and to extend a life of the battery.

Abstract: An apparatus and a method to charge a battery, the battery charging apparatus including: a battery unit which is chargeable; a battery charging unit which charges the battery unit; and a controller which adjusts a preset charge voltage of the battery unit based on a charge allowance capacity of the battery unit to have a predetermined value, and controls the battery charging unit to output the adjusted charge voltage and to charge the battery unit. Accordingly, the apparatus and method are capable of charging a battery based on a charge allowance capacity decreased owing to deterioration of the battery to safely use the battery and to extend a life of the battery.

Abstract: A portable computer system comprises a main body and an LCD apparatus having an LCD panel and a back light for illuminating the LCD panel. The system further comprises: a DC/AC inverter for supplying AC power to the back light; a contrast sensing part for sensing contrast of a video signal displayed on the LCD panel; a DC converter for converting a PWM signal outputted from the contrast sensing part into a DC signal; a voltage controller causing the DC signal from the DC converter to be appropriate for an operating voltage of the DC/AC inverter so as to supply the operating voltage to the DC/AC inverter; and a controller for sensing the operating voltage of the DC/AC inverter, and for controlling the voltage controller on the basis of the operating voltage. With this configuration, the brightness of a back light can be automatically controlled according to a contrast sensed by a contrast sensing part regardless of the input impedance of the inverter.

Abstract: A portable computer system comprises a main body to which a power supplying unit is connected, and an LCD apparatus having an LCD panel operated by electric power supplied by the power supplying unit and a back light for illuminating the LCD panel. The system further comprises: a DC/AC inverter for supplying AC power to the back light; a contrast sensing part for sensing contrast of a video signal displayed on the LCD panel; a DC converter for converting a PWM signal outputted from the contrast sensing part into a DC signal; a voltage controller provided between the DC converter and the DC/AC inverter, and causing the DC signal from the DC converter to be appropriate for an operating voltage of the DC/AC inverter so as to supply the operating voltage to the DC/AC inverter; and a controller connected in series with the DC/AC inverter for sensing the operating voltage of the DC/AC inverter, and for controlling the voltage controller on the basis of the operating voltage.

Abstract: A device and a method for displaying an exact charge capacity of a smart battery includes a portable electric device including a control unit for power management. The portable electric device includes a battery for providing a relative state of charge (RSOC), a control unit for controlling the device to display battery residual capacity information by receiving the RSOC from the battery, and a display unit for displaying the battery residual capacity information. Here, the control unit detects an output voltage of the battery, compares the detected voltage with the RSOC, and controls the device to display the battery residual capacity information in response to data corresponding to the detected voltage, when the battery is in a period of a first low battery and the detected voltage is different from the RSOC, or controls the device to display the battery residual capacity information in response to the RSOC when the battery is in a period of a second low battery lower than the first low battery.

Abstract: A device and a method for displaying an exact charge capacity of a smart battery includes a portable electric device including a control unit for power management. The portable electric device includes a battery for providing a relative state of charge (RSOC), a control unit for controlling the device to display battery residual capacity information by receiving the RSOC from the battery, and a display unit for displaying the battery residual capacity information. Here, the control unit detects an output voltage of the battery, compares the detected voltage with the RSOC, and controls the device to display the battery residual capacity information in response to data corresponding to the detected voltage, when the battery is in a period of a first low battery and the detected voltage is different from the RSOC, or controls the device to display the battery residual capacity information in response to the RSOC when the battery is in a period of a second low battery lower than the first low battery.

Abstract: A battery monitoring system determines an accurate residual capacity of a battery in consideration of variation of battery temperature, amount of battery self-discharge, and amount of battery discharge from a host device, such as a portable computer. The monitoring system further determines a predicted remaining operating time of the device. The battery capacity measuring apparatus includes a microcontroller, a battery pack, a battery temperature detection circuit, a battery voltage detection circuit, a load current detection circuit, and a power saving level detector. The microcontroller is coupled to a host device such that it indicates the battery residual capacity along with the remaining operating time of the device via a display.

Abstract: Disclosed herein is a battery powered computer system which comprises a switch circuit and a battery charging circuit. In the switch circuit, a field-effect transistor (FET) is provided which is connected in parallel with a diode for preventing a current back flow from a battery to an alternating current (AC) adaptor. When the alternating current adaptor is supplying power, the field-effect transistor is turned on so that most of a current from the alternating current adaptor is delivered to a power supply line through the transistor instead of the diode. Similarly, in the battery charging circuit, a field-effect transistor is implemented which is connected in parallel with a diode for preventing a current back flow from the battery to the alternating current adaptor. When the battery is charged, the field-effect transistor is turned on so that most of a charging current is transferred to the battery through the transistor instead of the diode.

Abstract: A battery charging apparatus for use with batteries that require charging in a constant current mode and/or constant voltage mode. The charging apparatus includes a constant current charging control circuit converting the charging current supplied with the battery into a voltage signal and applying the voltage signal to a feedback input terminal of a switching regulator in response to a charging speed control signal F.sub.-- Q, and a constant voltage charging control circuit providing a control signal to the feedback input terminal for controlling constant voltage charging if the battery voltage level has reached a preset voltage level, whereby a constant voltage charging is possible during the charging operation in response to a charging mode selection signal CHG.sub.-- MOD. A microcomputer produces the charging mode selection signal CHG.sub.

Abstract: A power supply system for a portable device such as portable personal computer, to be operated from a DC power source supplied from a rechargeable battery or an AC adapter includes: an input current detecting circuit for detecting an input current supplied from the AC adapter and for generating a detection signal having a magnitude which varies depending upon the input current, and a charging current control circuit for controlling the amount of the charging current in response to the detection signal. The power supply system has low power losses and effects a high efficiency battery charging.

Abstract: A rechargeable battery charging circuit comprises a detection circuit for detecting the ambient temperature and a charging current control circuit for controlling the charging current in dependence upon the ambient temperature. The battery charging circuit charges the battery in response to the ambient temperature variations in order to maximize the charging efficiency of the battery at temperatures higher than room temperature.

Abstract: A mode-convertible battery charging apparatus is provided. According to the invention, regardless of whether the battery being charged is a completely discharged battery, a fully charged battery or a battery which has a certain amount of electric charge, charging is automatically completed only after the battery is fully charged. Users can detect the charged state of the battery pack, and therefore life shortening of or a damage to the battery due to overcharging of the battery pack can be avoided so as to increase the reliability of the battery. When the detected voltage goes beyond the limit of automatic charging control, the charging operation is not conducted so as to prevent battery damage due to overcurrent.

Abstract: A backlight luminescence control device for use in a portable computer to control a backlight of a liquid crystal display. When an AC adaptor is not connected to the portable computer, the device senses the voltage level of a DC battery and generates an electrical signal that indicates the status of the battery. From the voltage level of the DC battery, the device ascertains the appropriate luminescence level of a cold-cathode fluorescent backlight lamp (CCFL), automatically controls the brightness of the CCFL through several levels of luminosity, and optimizes the luminescence of the CCFL according to the voltage level available in the DC battery.

Abstract: A back light circuit for a liquid crystal display (LCD) includes: an alternating current (AC) adapter, a battery for supplying a direct current (DC) when the alternating current (AC) adapter is not used, an adapter detecting unit for determining whether or not the alternating current (AC) adapter is being used, a direct current/direct current (DC/DC) converter for providing output of a switched signal, a direct current/alternating current (DC/AC) converter for driving a cold cathode fluorescent lamp (CCFL) by increasing an electric potential, a cold cathode fluorescent lamp (CCFL) operated by the direct current/alternating current (DC/AC) converter, an on/off controller for controlling the direct current/direct current (DC/DC) converter, a brightness controller for controlling the brightness of the cold cathode fluorescent lamp (CCFL), a feedback unit for providing feed back signals to the direct current/direct current (DC/DC) converter, a brightness condition detector for determining the brightness condition