Abstract: A battery charging circuit, a method of charging a battery and a battery-powered electronic device employing the circuit or the method. In one embodiment, the battery charging circuit includes a charging switch coupled between a base interface of the battery-powered electronic device and a battery thereof to be charged. When closed, the charging switch provides a conductive path for charge current from the base interface to the battery. The charge current is based on an input voltage of the battery charging circuit and a voltage of the battery. The battery charging circuit further includes a controller that modulates the charging switch at a duty cycle that at least in part determines a rate at which the charge current is delivered to the battery thereby to compensate at least in part for variations in the input voltage.

Abstract: In an automobile power supply where plural voltages can be supplied, a plurality of batteries and a DC/DC converter are assumed to be unnecessary, and it is possible to operate even when the controller breaks down.

Abstract: The present invention concerns a system and an apparatus for monitoring the electrical condition of an automotive battery [2] in use. The main purpose of this invention is to monitor and indicate automotive battery conditions, namely liquid electrolyte level and level of battery plate deterioration using the concept of ripple voltage. The present invention utilises ripple voltage present in battery supply line [4] as reference to deduce the condition of the said battery [2]. The method comprises the steps of first measuring the ripple voltage present in battery supply line [4] when engine is running, comparing the ripple voltage to a range of acceptable values determined by how bad the deterioration of battery is before issuing a signal or by nominal setting that best fit automotive vehicles and lastly providing indication when the ripple voltage exceeds the range of pre-set values.

Abstract: Apparatus and attendant methodology for extracting maximum power from an energy source, such as a photo voltaic panel, an array of photo voltaic panels, or a windmill and delivering that power to a battery or an array of batteries is disclosed. The apparatus determines the maximum operating point of the energy source, and circuits and circuit topologists are presented for extracting the energy. The apparatus eliminates the problem of finding local maximum points, and problems attendant variations of the absolute maximum power point as a function of temperature, insolation, array construction, and photo voltaic panel manufacturing tolerances. The energy source supplies power in the form of a voltage and charges the batteries with a controllable current source.

Abstract: An output variable charging circuit has a charging control circuit for controlling charging characteristics so as to satisfy a predetermined charging condition; and a charging characteristic detection circuit connected to the charging control circuit, the charging characteristic detection circuit detecting the charging characteristics to obtain a charging characteristic detection value and changing the charging characteristic detection value according to an input external signal so as to feedback to the charging control circuit.

Abstract: A USB cable according to the present invention has a USB connector connected with a USB port of a PC (Personal Computer), a phone connector connected with a connector of an external connector such as a mobile phone, a control unit, which is situated between the USB connector and the phone connector, for charging a battery of the mobile phone by using power supplied from the USB port of the PC and for transmitting and receiving data with the PC and the mobile phone, and a cable for connecting the USB connector and the phone connector with the control unit respectively.

Abstract: A DC—DC converter generates a system output current and a battery charging current. The converter has an output transistor connected between an AC adapter, which provides a supply current, and a terminal at which the battery charging current is provided. A control circuit generates a duty control signal used to activate and deactivate the output transistor in order to adjust the battery charging current. The control circuit includes a voltage detection circuit that compares a DC power supply voltage of the AC adapter with a first reference voltage and generates a differential voltage signal from the comparison result. A PWM comparison circuit is connected to the voltage detection circuit and compares the differential voltage signal with a triangular wave signal to generate the duty control signal which has a duty ratio corresponding to the comparison result.

Abstract: A battery charging system may include a permanent magnet alternator. The system uses controlled rectifiers to supply charging output from an alternator to the battery, to control the charging current and to provide a taper charge. The system may also use a voltage regulator coupled with the controlled rectifiers. The voltage regulator progressively deactivates the controlled rectifiers, in response to the state of charge of the battery, to provide a taper charge. The alternator may be used in vehicles, including automobiles, and for other electrical generating purposes.

Abstract: A solid-state secondary lithium battery with excellent charge and discharge cycle characteristics, using a negative electrode active material which shows discontinuous change of potential caused by the lithium ion insertion and extraction reactions, wherein the amount of the lithium ion inserted, until discontinuous change of potential of the negative elctrode takes place, is equal to or smaller than the maximum amount of extraction of lithium ions within the range where lithium ions are inserted and extracted into or from the lithium transition metal oxide reversibly, and a battery assembly using these batteries.

Abstract: A battery charger to recharge a battery comprises a transistor switch coupled with a cable loss compensator. Additionally, the battery charger includes a comparator, a current limiter, and a differential amplifier. The circuits are created from discrete components, and particularly include individual transistors. A smoothing network takes the signal from the switch and passes it along to the battery for recharging.

Abstract: A power accessory for apportioning electrical current between an electronic device and a rechargeable battery used in connection with the device includes two current limiting circuits. The first current limiting circuit limits the current supplied to the device to the peak current that device may demand. Any remaining current from the first current limiting circuit is passed through the second current limiter to the recharge the battery based on a charging algorithm. When the battery is fully charged, the second current limiting circuit stops providing current to the battery.

Abstract: Method and circuitry for clamping outputs of inactive error amplifiers in battery chargers eliminate delays and prevent oscillatory tendencies. By clamping the output of, for example, an inactive current loop amplifier in response to the output of an active voltage loop amplifier in a battery charging circuit, the inactive amplifier is prevented from saturating, such that it can take over as the controlling loop with minimal delay.

Abstract: A method of charging a rechargeable lithium battery which comprises charging the battery with a charging current; sampling a charging voltage of the battery during charging to recognize potential electrolyte decomposition; interrupting the charging current periodically to create current-free periods and sampling an open circuit voltage of the battery at a plurality of points during each current-free period to identify potential shunting and unequal states of charge among individual cells of the battery; lowering the charging current if any of the above-identified adverse conditions are identified and continuing charging with the charging current if the potential adverse charging condition is not identified; and terminating charging when the charging current is lowered below a pre-determined minimum level.

Abstract: To enhance the performance as well as the reliability and safety of a charge/discharge control circuit and a charging type power-supply unit using it, a charge/discharge control circuit 102 is made to have a circuit construction wherein when a load 109 has been connected at a time of a secondary cell 101 being charged and being in a state having been protected from the charging operation, the state of protection from the charging operation is released to thereby make a switch circuit 103 "on" and permit effective performance of the discharging operation while, on the other hand, when a transition occurs from even this state to a state where excess current is consumed from the secondary cell 101 and as a result an excessive amount of current flows through the switch circuit 103, control can be made so that the discharging from the secondary cell 101 may be stopped, thereby enabling avoidance of the FETs from breakage.

Abstract: Apparatus for extending the battery life of a seasonal-use battery. The apparatus is an improvement in a seasonal-use device having a battery charging system, wherein the battery charging system includes a voltage step-down device coupled to the charging system. The improvement includes a mechanism integral the battery charging system for providing a maintenance current to the battery proximate the battery's self-discharge rate. A mechanism is provided for coupling the battery charging system to an external power source. The apparatus for extending the battery life may also be coupled to the seasonal-use device system controller.

Abstract: The present invention measures the energy consumption of battery-powered telephone devices to prevent the inadvertent deep discharge of a vehicle's battery by prolonged use of said devices when the vehicle is unattended. In a preferred embodiment, current to the devices is incrementally measured or estimated from a measurement of other relevant parameters. The incremental measurements of current are accumulated to produce a total current consumption indicative of the total energy consumption. At each update after an incremental measurement, the accumulated total is compared to a pre-established or adaptively determined. When the total energy consumption meets or exceeds the threshold, the power to the battery-powered telephone device is interrupted in order to conserve a sufficient amount of power to start the vehicle and to operate other peripheral systems.

Abstract: A battery protection system (20) controls a process for charging a battery pack (15). A hysteresis comparator (54) senses a charging current flowing through the battery pack (15) and switches off a charging switch (31) to interrupt the charging current when the charging current reaches an upper limit. A transient current is then generated by an inductor (34). The hysteresis comparator (54) senses the transient current flowing through the battery pack (15) and switches on the charging switch (31) to regenerate the charging current when the transient current decreases substantially to zero. Periodically, a battery monitoring circuit (40) switches off the charging switch (31) and measures an open circuit voltage across each battery cell in the battery pack (15). In response to the open circuit voltage of a battery cell reaching a fully charged voltage, the battery monitoring circuit (40) switches off the charging switch (31) to terminate the charging process.

Abstract: A battery pack for use in a portable computing system includes a transistor that is used both for inhibiting charging of the batteries within the system and for limiting the voltage across the batteries in the battery pack. Rather than having two separate devices to inhibit and regulate, this single transistor performs the functions of both, thus reducing component count in a battery pack.

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 bidirectional current control circuit suitable for use in controlling the charging and discharging of rechargeable battery cells includes two serially connected metal oxide semiconductor field effect transistors (MOSFETs) with respective body diodes, a resistor which is connected in series with the MOSFETs and develops a voltage based upon the current through such MOSFETs, and a control circuit. The control circuit monitors the voltage across the resistor and selectively switches the MOSFETs on or off individually. As long as the current through the MOSFETs is less than a maximum positive current and more than a minimum negative current, both MOSFETs are maintained in their respective on states. When the negative current becomes less than a minimum negative current, the first MOSFET is turned off while the second MOSFET is turned on, and when the positive current becomes greater than a maximum positive current, the second MOSFET is turned off while the first MOSFET is turned on.

Abstract: A power supply device includes a secondary battery and a charger, and can further utilize an external D.C. power supply. A switch is interposed between a negative electrode of the secondary battery and the ground. This switch is turned OFF when the external D.C. power supply is connected to the power supply device, and is turned ON when the external D.C. power supply is removed from the power supply device. The charger controls the charge of the secondary battery from the external D.C. power supply by regulating the potential of the negative electrode of the battery. A contact remains OFF while the external D.C. power supply is connected to the power supply device. In consequence, a current does not directly flow from the external D.C. power supply to the secondary battery. Therefore, a back-flow prevention diode, which otherwise results in power consumption, need not be disposed between the secondary battery and the load.

Abstract: An apparatus for charging a battery has a power supply terminal, a controllable power control switch coupled to said power supply terminal, a charging circuit having a charging terminal for connection to a terminal of the battery, and means for opening and closing the power control switch if a battery is disconnected or connected to the charging terminal, respectively. The means for opening and closing the power control switch may include an analog circuit, a digital circuit, a hybrid analog/digital circuit or a mechanical switch. A method of controlling a power control switch of a battery charging system is disclosed, comprising the steps of generating a reference voltage level, sensing the voltage level at the charging terminal, comparing the voltage level at the charging terminal to the reference voltage, and controlling the power control switch in response to the comparison of the reference voltage level and the voltage level at the charging terminal.

Abstract: A transformerless battery feed circuit for a digital telecommunications line (100) presents a high impedance to digital signals and a low impedance to direct current, and provides a constant-voltage feed with current limiting. The battery feed circuit comprises a pair of transformerless controlled current sources, one for each lead (T,R) of the line, each taking the form of a high-gain transistor (Q1, Q2) having a collector coupled to a source of power (e.g., a battery V1), a base resistively coupled to the power source and capacitively coupled to its corresponding lead, and an emitter coupled to its corresponding lead. The battery feed circuit further comprises a pair of control circuits, one for each current source, each taking the form of a transistor (Q3, Q4) having a collector coupled to the base of the corresponding high-gain transistor, a base resistively coupled to the emitter of the corresponding high-gain transistor and to the power source, and an emitter coupled to the corresponding lead.

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 battery protection system (20) controls a process for charging a battery pack (15). A hysteresis comparator (54) senses a charging current flowing through the battery pack (15) and switches off a charging switch (31) to interrupt the charging current when the charging current reaches an upper limit. A transient current is then generated by an inductor (34). The hysteresis comparator (54) senses the transient current flowing through the battery pack (15) and switches on the charging switch (31) to regenerate the charging current when the transient current decreases substantially to zero. Periodically, a battery monitoring circuit (40) switches off the charging switch (31) and measures an open circuit voltage across each battery cell in the battery pack (15). In response to the open circuit voltage of a battery cell reaching a fully charged voltage, the battery monitoring circuit (40) switches off the charging switch (31) to terminate the charging process.

Abstract: A charging terminal shortcircuit preventing circuit for a battery pack, capable of firmly preventing a shortcircuit and with employing a simple structure. In a battery pack so constructed that a charge current is supplied from a charger via a charging terminal to a battery, and a current is supplied from the battery via an output terminal to a portable appliance, and further the current from the charger via a through-input terminal and a through-output terminal to the portable appliance, there are provided a switch 22 for turning ON/OFF the charge current between the battery 21 and the charge terminal T.sub.4, and switch operating means for detecting an application of a voltage to the through-input terminal T.sub.6 to thereby turn ON the switch 22. Also, in a battery pack 2, a resistor having a large resistance value is connected parallel to the switch 22, and a battery pack mount detecting means of the charger 3 detects a voltage at the charging terminal T.sub.

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: A system and method for automatically enabling rapid charging of a battery in a portable phone when a battery charger is connected to the portable phone is disclosed. The system includes a battery charger circuit having an input for receiving an input voltage from the battery charger, a sense resistor through which a rapid charging current from the battery charger input voltage is generated, a charge switch connected to the sense resistor which receives the battery charger circuit input, a trickle resistor connected in parallel to the charge switch through which a slow charging current from the battery charger input voltage is generated, wherein the rapid charging current is generated when the charge switch is closed and the trickle charging current is generated when the charge switch is open, and an output for supplying the generated charging current to the battery.