Abstract: A power supply apparatus according to the present invention includes a battery and a voltage detection circuit for detecting the voltage of the battery. The voltage detection circuit includes a differential amplifier which has a first input terminal for receiving a voltage based on the voltage of the battery and a second input terminal for receiving a predetermined triangular wave and outputs a rectangular wave with a pulse width modulated according to the voltage based on the voltage of the battery and a predetermined offset voltage, and an offset circuit which supplies the offset voltage to one of the first input terminal and the second input terminal so that the differential amplifier outputs a particular rectangular wave according to the offset voltage even when the voltage based on the voltage of the battery which is supplied to the first input terminal is 0.

Abstract: A battery charging circuit having two levels of safety protection is provided. The circuit is said to have “two levels” of safety because if any one component fails (either as a short circuit or as an open circuit) the remainder of the charging circuit ensures that a rechargeable battery coupled to the circuit will not be overcharged. The circuit includes both hardware and firmware protection components, with a microprocessor providing the firmware protection. Overvoltage protection, voltage regulation and current regulation are provided, along with a microprocessor capable of sensing a plurality of voltages across the circuit. The overvoltage protection, voltage regulator and current regulator each include safety actuation points. In parallel, the microprocessor may isolate a rechargeable battery from the cell if voltage and current minimums and maximums are exceeded.

Abstract: This invention includes a circuit for displaying charge status to a user. The circuit includes circuitry for comparing a supply or reference voltage to a cell voltage, circuitry for sensing charging current and circuitry for displaying at least one of three charging states to a user. The circuit compares the supply or reference voltage to the cell voltage while sensing current. If the difference between the supply or reference voltage is great, and current is small, the circuit indicates a trickle charging mode. If the charging current is large, the circuit indicates rapid charge. If the difference between the supply or reference voltage is small, and the current is small, the circuit indicates a top off mode. The circuit preferably includes a plurality of comparators for both sensing and comparing the voltages and currents. A pair of light emitting diodes preferably indicates the state of charge to the user.

Abstract: The charging method includes the steps of charging a battery pack, sensing voltage of the battery pack, calculating voltage change rate, detecting a first inflection point based on the voltage change rate so long as a voltage step is not detected, detecting a second inflection point based on the voltage change rate so long as a voltage step is not detected, and reducing current sent to the battery pack when both first and second inflection points have been detected.

Abstract: The present invention relates to a device and a method for the detection of a charging voltage of at least one rechargeable battery comprising a voltage converter for converting the charging voltage of the at least one rechargeable battery into a voltage signal, an analog/digital converter for converting the voltage signal of the voltage converter into a digital signal, and an evaluation and control device for evaluating the digital signal of the analog/digital converter as well as for controlling the charging process of the at least one rechargeable battery on the basis of the evaluation of the digital signal of the analog/digital converter. The voltage converter comprises an amplifier circuit with a variable gain controlled by at least one control output terminal of the evaluation and control device such that the gain applied for the generation of the voltage signal is adjusted to the input voltage range of the analog/digital converter according to a transfer function.

Abstract: In order to prevent discharge of the battery (3) of a motor vehicle during operation of heavy current consumption devices, a circuit configuration is to be prepared which comprises essentially a rotary current generator (1), a vehicle battery (3), one or more current consuming devices (4), and a controllable voltage converter (2). The voltage converter (2) supplies an output voltage which varies as a function of the control signal of a control unit (10) of the current generator (1) and which supplies the current consuming device (4). In the event of overloading of the rotary current generator (1) the output voltage of the voltage converter (2) is lowered in order to reduce the current consumption of the device (4) and prevent overloading of the rotary current generator (1) and discharge of the vehicle battery (3).

Abstract: A voltage mode battery charging system is provided that includes a battery current control section, a battery voltage control section, and a power control section. The battery current control section and battery voltage control section each generate signals indicative of the battery charging current and battery voltage, respectively. The power control section generates a signal indicative of the power available from an adapter source. Each of these signals is combined at common node, and if any of these sections exceeds a threshold, battery charging current is decreased.

Abstract: The charging method includes the steps of charging a battery pack, sensing voltage of the battery pack, calculating voltage change rate, detecting a first inflection point based on the voltage change rate so long as a voltage step is not detected, detecting a second inflection point based on the voltage change rate so long as a voltage step is not detected, and reducing current sent to the battery pack when both first and second inflection points have been detected.

Abstract: A power management topology for portable electronic devices that includes a feed-enabled AC/DC adapter that receives feedback data from a charge controller associated with the portable device. The feedback data can include battery charging current, battery voltage, or power requirements of the portable device. Using the feedback data, the external AC/DC adapter can adjust the DC output to meet the charging requirement of the battery and/or the power requirements of the portable device.

Abstract: A voltage mode battery charging system is provided that includes a battery current control section, a battery voltage control section, and a power control section. The battery current control section and battery voltage control section each generate signals indicative of the battery charging current and battery voltage, respectively. The power control section generates a signal indicative of the power available from an adapter source. Each of these signals is combined at common node, and if any of these sections exceeds a threshold, battery charging current is decreased.

Abstract: An apparatus and method is related to a shunt regulator that includes two feedback control loops. The shunt regulator provides a charging current to a battery cell from a power source. The input voltage from the power source is limited by the first feedback control loop to ensure that the input voltage does not exceed the breakdown voltage of the shunt regulator. The output voltage from the shunt regulator is limited by the second feedback control loop to ensure that the output voltage does not exceed the maximum rated voltage of the battery. The dual feedback control loops provide maximum charging current to the battery, while protecting the shunt regulator and the battery from damage. The shunt regulator is suitable for implementation in an integrated circuit.

Abstract: A voltage mode battery charging system is provided that includes a battery current control section, a battery voltage control section, and a power control section. The battery current control section and battery voltage control section each generate signals indicative of the battery charging current and battery voltage, respectively. The power control section generates a signal indicative of the power available from an adapter source. Each of these signals is combined at common node, and if any of these sections exceeds a threshold, battery charging current is decreased.

Abstract: A voltage mode battery charging system is provided that includes a battery current control section, a battery voltage control section, and a power control section. The battery current control section and battery voltage control section each generate signals indicative of the battery charging current and battery voltage, respectively. The power control section generates a signal indicative of the power available from an adapter source. Each of these signals is combined at common node, and if any of these sections exceeds a threshold, battery charging current is decreased.

Abstract: In a battery charger for charging a plurality of battery cells connected in series with each other with a constant current in a batch manner, the present invention is intended to suppress the generation of heat in cell shunt circuit sections which are provided as overheat protective measures for the individual cells. Surplus energy, which is generated in the cell shunt circuit sections by the product of a cell voltage and a shunt current and which becomes a heat generating source, is regenerated to a charger side via a flyback transformer provided in each of the cell shunt circuit sections, thereby suppressing heat generation.

Abstract: A battery pack includes a lead-acid battery and a charger port and an electronic switch connected between the two, the switch being controlled by a microcontroller which is connected to each of the battery and the charger port for separately monitoring the voltages thereat.

Abstract: A method and apparatus for implementing an improved pulse width modulation circuit is disclosed. In particular, a circuit and method is provided to generate a pulse width modulated signal, wherein the circuit and method significantly reduce susceptibility to transient noise effects. The pulse width modulator according to the present invention operates at high frequencies and over a full duty cycle range of 0% to 100%. Furthermore, automatic self-correction logic is also disclosed for pulse width modulated circuits wherein the self-correction logic prevents fault conditions.

Abstract: A battery charge controller has charge termination values that can be adjusted according to the initial charging current values so that charging is discontinued at a same charge level for all battery cells to prevent overcharging and undercharging. The battery charge controller includes a DC/DC converter that is coupled to a supply voltage and that provides a charging current to a battery, and a gain controller coupled to the DC/DC converter. The gain controller provides first and second gain-adjusted signals associated with the charging current. The charge controller further includes a charge termination detector that compares the level of the second gain-adjusted signal to a first predetermined reference signal and based on the comparison generates a charge termination signal. A pulse-width controller is coupled to the DC/DC converter.

Abstract: A method of monitoring the condition of the battery of a smoke or heat alarm so as to provide a warning of an impending low battery condition, said method including: means of providing a low battery alarm to warn of a low battery condition, the said condition being that of a battery which has depleted to an energy level at and below which it is recommended that the battery be replaced to maintain the full functionality of the alarm device; means of providing an additional low battery pre-alarm to warn of an impending low battery condition, the said low battery pre-alarm being provided when the smoke or heat alarm battery has depleted to an energy level which is slightly higher than, but close to, the energy level that would generate the low battery alarm, and means of bypassing or silencing the low battery pre-alarm, in the event of an impending low battery condition, should a new battery not be available to immediately replace the depleted smoke or heat alarm battery, with the result that the occupants of th

Abstract: A method of charging rechargeable batteries with a switch mode power supply, the method comprising determining one or more battery charging parameters, and controlling the power output of the switch mode power supply by digitally generating a gate signal for controlling opening periods and closing periods of a switching means of the switch mode power supply, each of the durations of the opening periods and the closing periods of the switching means, respectively, being determined in response to the determined one or more battery charging parameters and one or more charging process reference values. In particular, a method is proposed of controlling the duty cycle of a switch in the switch mode power supply during charging of the battery based on determinations of one or more characteristic charging parameters of the charging process and comparisons of determined parameter values with desired parameter values.

Abstract: A battery charger for fast charging batteries, such as batteries requiring constant current charging, such as lithium ion batteries. The battery charger provides charging voltages across a battery pack having at least one rechargeable cell connected to battery terminals. The battery charger includes a digital to analog converter circuit for controlling a current source for supplying a charging current to the battery pack. The digital to analog converter may provide a constant current or a constant voltage output as a function of the battery characteristics. An analog to digital converter measures a first voltage across the battery pack while the battery pack is being charged and a second voltage across the battery pack while the charging current is interrupted, and a digital processor determines the potential difference between the first voltage and the second voltage to determine a voltage drop across the terminals of the battery pack.

Abstract: An improved battery charger and reconditioner employs a charging sequence calling for a discharge pulse to be applied substantially immediately before a charging pulse to effectively lower the impedance of the subject battery and to thereby more effectively charge the battery at a lower voltage level. The apparatus and method of the invention enhances the current receiving properties of the battery to lower thermal properties associated with charging and to more efficiently and more rapidly charge a subject battery. The charging sequence reconditions a battery by applying the improved sequence so as to rejuvenate an otherwise damaged battery. The invention also provides a method and means for formatting a battery and for removing dendritic formations which occur in a battery. Further, methods for aborting battery charging and for detecting abnormal conditions are also provided by the present invention.

Abstract: A battery charger for use with different types of batteries, such as batteries requiring constant current charging, such as nickel cadmium (NiCd) and nickel metal hydride (NiMH) batteries, as well as batteries which not only require constant current charging, but also require constant voltage charging, such as lithium ion batteries. The battery charger includes a pulse width modulator circuit for controlling a power transistor to provide a constant current or a constant voltage output as a function of the battery characteristics. The battery charger may include dual pockets for charging two modular batteries on a time division multiplex basis. In the dual pocket application, power is divided between the two pockets as a function of the charging characteristics of the battery and the power dissipation of the power transistors used for supplying charging current to the pockets.

Abstract: In a battery charger, current regulating means and voltage regulating means can be prevented from damages. In the case where a loss of current regulating means (11) or voltage regulating means (12) exceeds an allowable loss, pulse width modulating means (15, 16) for generating a pulse signal having a desired pulse width and control means (18, 19) for intermittently operating the current regulating means or the voltage regulating means, having the loss exceeding the allowable loss, based on the pulse signal are provided to suppress the loss of the current regulating means or the voltage regulating means and suppress heat generated thereby, thus the current regulating means and the voltage regulating means can be protected from damages.

Abstract: The present invention relates to a pulse charging method and charging system for use with non-aqueous secondary batteries, employing a pulse charge controlling method all the way from the start to the end of charging. This pulse charging method has an on-duty ratio of pulses in a next specified charge period reduced when an average battery voltage has exceeded a charge control voltage during a specified charge period, has an on-duty ratio of pulses in a next specified charge period increased when the average battery voltage has not exceeded the charge control voltage and has the pulse charging ended when an on-duty ratio of pulses has reached a specified value. The pulse charging system comprises an on-duty ratio reducing means for having an on-duty ratio of pulses reduced, an on-duty ratio increasing means for having an on-duty ratio increased and a means for determining pulse charge ending for having the pulse charging ended when an on-duty ratio of pulses has reached a specified value.

Abstract: A battery charging circuit, particularly useful in a laptop computer system, includes a voltage input terminal coupled to a dc voltage. A first switch couples the voltage input terminal to an output coupled to the battery through a current sense resistor. A first current sink which is on when the charger circuit is on draws current from the input side of the current sense resistor through a first resistor to develop a first voltage. This voltage and a voltage coupled through a second resistor from the battery side of the sense resistor are inputs to a comparator, the output of which controls the first switch. A second current sink, when on, draws current through the second resistor causing the first switch to be held off, turning the charging circuit off. An ON/OFF terminal, to which a variable duty cycle square wave is supplied, controls the turning on and off of the first and second current sinks, with the length of the duty cycle controlling the average current supplied to the battery.

Abstract: A charging apparatus having a power supply circuit that provides a DC output current via a sense resistor. A current detector amplifies, detects and provides a voltage across the sense resistor. A controller designates the output of the current detector as a determination signal when the DC output current is equal to a preset voltage. Responsive to the determination signal, the controller generates a control signal in order to control the DC output current of the power supply circuit. More particularly, the current detector includes a first differential amplifier that amplifies and output the voltage across the sense resistor, a second differential amplifier amplifies and supplies a differential voltage between the output of the first differential amplifier and a predetermined first reference voltage, and a first output circuit responsive to the output of the second differential amplifier delivers the determination signal.

Abstract: A power supply system, for example, for use with a portable personal computer, includes a smart battery pack and a charging system. The smart battery pack is provided with a dedicated microcontroller for controlling the charging level of the battery charger system. In particular, the status of the battery including the voltage and temperature of the battery is applied to the microcontroller along with a signal representative of the current load demand of the computer system. The micro controller, in turn, provides a control signal in the form of fixed frequency, variable duty cycle pulse width modulated (PWM) signal for controlling the charging level of the battery charger system. The duty cycle of the PWM signal is used to regulate the charging current supplied by the battery charger. In particular, the DC value of the PWM signal is used as a reference to control the charging current of the regulator to provide a variable output charging current with a relatively wide current range.

Abstract: A method and apparatus for ultrarapidly charging primary or secondary battery. Charging current is multiple-frequency complex pulse current which is comprised of pulse current overlapped by pulse current with at least two different frequency band and arbitrary waveform and opposite narrow pulse whose amplitude is three times higher than amplitude of said pulse current. The charging current may be larger than 1.5C10 and charging is performed in a manner of no discharging. Charging circuit is comprised of at least two different frequency oscillators, switch circuit and opposite narrow pulse generating circuit. The pulse current of different frequency may overlap each other, modulated and scanned and varied on frequency to generate multiple-frequency complex charging current.

Abstract: An apparatus and method for recharging a battery. The invention includes modulating a rail voltage with a modulation signal that oscillates at a radio frequency, preferably at a frequency that matches the natural resonant frequency of the battery. The modulated rail voltage is provided to the battery to recharge the device. The apparatus may have a follower circuit which shifts the modulation frequency to follow any change in the natural resonant frequency of the battery.

Abstract: A self-oscillating buck mode battery charger apparatus 10. The apparatus 10 includes a main switching transistor 22, a first control transistor 34 and a second control transistor 36. The control transistors 34 and 36 are arranged such that neither control transistor sees the full input mains voltage across input terminals 12 of the apparatus 10 when the switching transistor 22 is turned off. An alternative embodiment of the invention includes a high and low main sensing circuit 102 in which a controller 120 is used to detect an excessively high mains voltage condition as well as an undesirably low mains voltage condition. The controller 120 turns off a PWM control circuit 104 when either condition is present for a predetermined length of time. Turning off the PWM control circuit 104 causes the main switching transistor 106 to be turned off, thereby preventing damage to the components of the charger apparatus 100.

Abstract: Operational transconductance amplifiers (OTAs) are combined at their outputs, yielding a single frequency compensation connection point. In a preferred embodiment, the output of each OTA is asymmetric, i.e., they can only source current and the OTA outputs are tied together to a constant current sink. Consequently, the OTA that sources more current controls the voltage of the merged output. This merged output point provides a voltage output that may be used as a frequency compensation point.

Abstract: An apparatus for programmably adjusting output voltage of a constant-voltage battery charger is disclosed. The present invention includes a power circuit for generating an output voltage for charging batteries. This power circuit generates this output voltage as a function of an incoming power source and an incoming error signal. The invention further includes a controller for providing a pulse width modulated (PWM) signal operating at a pre-determined frequency. This PWM signal controls the effective divider ratio of a voltage divider network which is implemented, among other things, for generating the error signal to be fed to the power circuit. The present invention varies the effective divider ratio by programmably applying the pulse width modulated signal from the controller. As a result, the output voltage from the power circuit can be varied to optimally charge batteries of differing types and technologies.

Abstract: A battery charger for use with different types of batteries, such as batteries requiring constant current charging, such as nickel cadmium (NiCd) and nickel metal hydride (NiMH) batteries, as well as batteries which not only require constant current charging, but also require constant voltage charging, such as lithium ion batteries. The battery charger includes a pulse width modulator circuit for controlling a power transistor to provide a constant current or a constant voltage output as a function of the battery characteristics. The battery charger may include dual pockets for charging two modular batteries on a time division multiplex basis. In the dual pocket application, power is divided between the two pockets as a function of the charging characteristics of the battery and the power dissipation of the power transistors used for supplying charging current to the pockets.

Abstract: The charging method repeatedly charges and suspends charging to pulse charge a rechargeable battery. Charging is suspended only after a given amount of charge is transferred to the battery. Battery voltage is measured during the period of suspended charging, and charging is resumed only after the voltage of the battery drops below a first prescribed voltage. This situation is continuously repeated to pulse charge a rechargeable battery.