Abstract: The present disclosure is an energy-efficient rapid battery charger, using inductive windings rather than transformer to charge a battery. The apparatus operates with an AC power source rectifying a high voltage DC output or AC source transformed to a low DC voltage output. The control driver frequencies vary from several hundred Hz to thousand of Hz. A capacitor, inductor, and power line are arranged in a series parallel combination tank circuit that operates over the on and off time of a complete cycle. During on-time, the inductor is charged with electromagnetic power. During off-time, the electromagnetic power in the inductor discharges into the battery.

Abstract: To reduce power consumption when charging a secondary battery is not performed, a first power supply circuit is disabled but a second power supply circuit is enabled when the secondary battery is unloaded from a battery charger. Both the first and second power supply circuits are enabled when the battery is loaded in the charger. The first power supply circuit is provided for supplying power to the secondary battery. The second power supply circuit is provided for supplying a first voltage to such components that are operated with the first voltage and a second voltage to such components that are operated with the second voltage, wherein the second voltage is greater than the first voltage. When the battery is unloaded from the charger, the second power supply circuit supplies only the first voltage whereas when the battery is loaded in the charger, the second power supply circuit supplies the first and second voltages to the corresponding components.

Abstract: A capacitor charging circuit comprises, power transfer circuitry, power switching control circuitry and voltage measurement circuitry. The power transfer circuitry transfers power from a power source to a capacitor. The power switching control circuitry controls the switching that causes power to be delivered to the power transfer circuitry. The voltage measurement circuitry indirectly measures the output voltage to determine when to stop charging the capacitor.

Abstract: The SOC of a battery is calculated based on the voltage Vb and current Ib of a battery, and a battery electromotive voltage Vbo is calculated based on the SOC of the battery. Based on the battery electromotive voltage Vbo and the voltage Vc of a capacitor connected on the output side of the DC/DC converter, a duty ratio D(=Vbo/2Vc) achieving the maximum battery power is set as the lower limit value DL of the optimum duty range DR, so that the lower limit value DL is varied according to the SOC of the battery. The duty ratio D is limited so as to fall within the optimum duty range DR, and the DC/DC converter is controlled to be driven using the limited duty ratio D.

Abstract: An information handling system includes a power source configured to provide a plurality of power levels to a load. At least one of the plurality of power levels corresponds to a level obtained by de-rating a capacity of the power source from a nominal design specification of the power source.

Abstract: A chargeable inverter power supply includes an inverter, a microcontroller unit (MCU) (1), a DC/DC converting circuit (9), and a charger electrically connected with the inverter. The charger includes two NI-MH, NI-CD battery charging circuits (10,11) and two battery voltage detecting circuits (12,13). Each component of the inverted power supply is controlled by the MCU. Voltages for the MCU and the NI-MH, NI-CD battery charging circuits are provided by the DC/DC converting circuit. The MCU is connected to a voltage detecting circuit (4), a power detecting circuit (6) and a temperature detecting circuit (8). In addition to act as an inverter power supply, the chargeable inverter power supply can also be used to charge NI-MH, NI-CD batteries (B1, B2).

Abstract: A method and an apparatus for charging a lithium-ion based rechargeable battery in a short time is provided.

Abstract: A mobile device having an overcurrent cutoff function. In a mobile device having at least one function module, the mobile device includes a main power supply which supplies power to the mobile device, a power detection unit which detects whether power from the main power supply to the mobile device is cut off, and generates a power cutoff signal when the power is cut off, a backup power supply unit which supplies a backup power to the mobile device when the power from the main power supply to the mobile device is cut off, and a control unit which converts potential levels of the data lines and control signal lines between the control unit and the function module to a predetermined potential level in response to the power cutoff signal.

Abstract: A device and a method are provided for equalizing the charge of the capacitors belonging to a double layer capacitor. The device includes an individual transformer associated with each individual capacitor and a flyback transformer or a spool, from which the energy is transferred, via the individual transformers, to the individual transformer, by the respective low charge. Conclusions on the state of the double layer capacitor and the charge-equalizing switch are derived from the measured charging time and discharging time of the flyback transformer.

Abstract: A detecting switch which is turned on/off in accordance with whether or not primary batteries have been attached to a primary battery holder is provided. In a normal state where no primary battery is attached, terminals (a, c) of a charge change-over switch are connected by a detection signal of the detecting switch, so that a voltage supplied from an external charger is inputted to a DC/DC converter. A secondary battery is charged by a predetermined value output of the DC/DC converter. When the primary batteries are attached, the detecting switch is turned on and terminals (b, c) of the charge change-over switch are connected, so that an output voltage of the primary batteries is inputted to the DC/DC converter. The secondary battery is charged by the predetermined value output of the DC/DC converter. Even when there is no charger, the secondary battery can be charged by the primary batteries and charging power sources are automatically switched.

Abstract: A sense amplifier adapted to amplify a voltage signal representative of a charging current provided to a rechargeable battery. The sense amplifier may include a p-type input sense amplifier and an n-type input sense amplifier, The p-type input sense amplifier may be enabled and the n-type input sense amplifier may be disabled if a battery voltage level of the rechargeable battery is less than an under voltage threshold level. The p-type input sense amplifier may be disabled and the n-type input sense amplifier may be enabled if the battery voltage level is greater than or equal to the under voltage threshold level. A related method and an electronic device having a sense amplifier consistent with an embodiment are also provided.

Abstract: By using a target voltage Vc* of a capacitor connected to the output side of a DC/DC converter and a voltage Vb of a battery connected to the input side of the DC/DC converter, a duty ratio D as a drive instruction of the DC/DC converter is calculated. By using the voltage Vb, the electromotive force Vbo of the battery, and the charge/discharge current Ib of the battery, an internal resistance Rb is calculated. According to the internal resistance Rb and the electromotive force Vbo, the current value when the battery output becomes maximum is set as the upper limit value of the optimal current range IR, the DC/DC converter is driven/controlled by limiting the duty ratio D so that the current Ib is within the range of the optimal current range IR. Thus, it is possible to appropriately convert the battery input voltage.

Abstract: In a capacitor charger, a transformer has a primary winding connected between an input voltage and a switch for generating a primary current flowing through the primary winding by switching the switch to thereby induce a secondary current flowing through a secondary winding of the transformer and a secondary voltage tapered from the secondary winding, a control apparatus and method adjusts the on-time period for the switch in response to the input voltage. The charging time and charging current are independent of the input voltage, and there is no power loss resulted from current sense to the primary current.

Abstract: A system and method for effectively managing operating power for an electronic device may include a battery pack coupled to the electronic device for supplying operating power to the electronic device. A battery controller may be configured as a single integrated-circuit device to alternately manage the battery pack either in a single-cell implementation or in a dual-cell implementation. The battery controller may include a charge pump device to provide an internal controller power supply for operating the battery controller in the single-cell implementation.

Abstract: A mobile host device configured to draw electrical energy from an energy storage device includes a disk drive. The disk drive includes a disk drive enclosure including a base, a spindle motor attached to the base, a disk positioned on the spindle motor, a generator and a charging circuit. The generator may be coupled to the disk drive enclosure and/or the mobile host device and generates electrical energy from the motion of the mobile host device and/or disk drive. The charging circuit is configured to charge the energy storage device using the electrical energy generated by the generator.

Abstract: A multi-mode renewable power converter system is disclosed. The system includes a control unit, a boost converter, an inverter and optional bi-directional charger, wherein the boost converter converts DC output of a solar cell or a renewable source to high DC bus voltage, and the inverter converts this DC bus voltage to an AC output. This power converter can be used to support standalone load or grid-connected system with a dynamic maximum power point tracking (MPPT) circuit. The MPPT circuit detects the current and voltage from the solar cell and indicates to the inverter to provide power to the load connected. When the optional bi-directional charger is installed, the MPPT signal is also fed to this charger to make the power efficiency maximized for the system.

Abstract: A regulator circuit capable of accurately adjusting output voltage anywhere in a current region and maintaining optimum output voltage by correcting setting of a predetermined voltage to be regulated depending on a value of charging current. An output terminal of an amplifier is connected to a reference voltage terminal through a resistance element. When charging current does not flow, detection voltage 0V. Consequently, voltage of a reference power source is divided between a resistance element R1 and parallel resistance elements R2 and R3. When charging current flows and detection voltage is outputted, the detection voltage is divided by resistance elements R2 and R3, whereby corrected voltage depending on a value of charging current is generated. Even if voltage drop occurs between a charging-control-device output terminal and a battery terminal, control voltage of output voltage is appropriately adjusted so that a battery terminal can keep full charging voltage.

Abstract: A portable electronic device connected to a network for receiving electrical power from the network. The portable electronic device includes a circuit for detectingand receiving electrical power over the network, and a power converter electrically connected to the circuit for receiving the electrical power from the circuit, converting the received electrical power such that converted electrical power has power characteristics compatible with the portable electronic device.

Abstract: A multi-mode renewable power converter system is disclosed. The system includes a control unit, a boost converter, an inverter and optional bi-directional charger, wherein the boost converter converts DC output of a solar cell or a renewable source to high DC bus voltage, and the inverter converts this DC bus voltage to an AC output. This power converter can be used to support standalone load or grid-connected system with a dynamic maximum power point tracking (MPPT) circuit. The MPPT circuit detects the current and voltage from the solar cell and indicates to the inverter to provide power to the load connected. When the optional bi-directional charger is installed, the MPPT signal is also fed to this charger to make the power efficiency maximized for the system.

Abstract: Power from a high voltage battery (10) (for example 36V) is supplied through an inverter (12) to a motor generator (14). A low voltage battery (20) (for example 12V) is connected through a reactor (18) to the neutral point of the motor generator (14). A voltage ratio of the low voltage battery (20) to the high voltage battery (10) is preferably from 1:2 to 1:4. In order to set the neutral point voltage to a desired charging voltage into the low voltage battery (20), the inverter (12) is controlled so as to follow a current distortion phenomenon. In this way, in a dual-power source system with a voltage ratio of a low voltage battery (20) to a high voltage battery (10) between 1:2 and 1:4, voltage switching means for use in charging a charge voltage of a high voltage side into a low voltage source can be implemented at low cost.

Abstract: A system 10 provides a variable output voltage to a DC brush motor. The system includes a DC brush motor 14, a DC voltage source 12, a step-up, step-down DC/DC converter 16 including a switch 18. The DC/DC converter is constructed and arranged to step-up and step-down voltage from the source to provide an output voltage to the motor between 0 and 42 volts. A control unit 22 is constructed and arranged to receive an input signal 20 and to control the switch based on the input signal to control the motor.

Abstract: The output of a generator 1 is rectified in a rectifier circuit (a drive inverter) 2. The output of the rectifier circuit 2 is converted into AC power of a predetermined frequency in an electronic power inverter section 3. A two-way DC-DC converter 4 is connected between the output side of the rectifier circuit 2 and the output terminal of the battery 5. The battery 5 is charged by the output of the rectifier circuit 2. Electric power is also supplied from the battery 5 to the load through the two-way DC-DC converter 4 when an overloaded state is caused and the output of the generator 1 cannot meet the demand for the load in the state.

Abstract: Disclosed herein is a method and system for configuring power electronics in an electrochemical cell system. Exemplary embodiments include power electronics having a power converter for an electrochemical cell system. The power converter includes a plurality of interchangeable power converter modules and a motherboard configured to receive the plurality of interchangeable power converter modules. A power rating of the power converter is capable of being changed by adjusting a number of the interchangeable power converter modules attached to the mother-board.

Abstract: A battery powered device, such as a breast pump, that includes a battery terminal that is configured to also serve a receptacle for an auxiliary power cord. The battery powered device also includes a battery stop that allows a pin, which is configured to receive the auxiliary power cord, to also serve as a battery terminal. More specifically, the battery stop prevents a user from over-inserting the battery into the battery cavity and thereby breaking or bending the battery terminal, which is typically configured as a pin that also functions as a male receptacle for the auxiliary power cord. In this manner, the battery stop allows the same pin to serve as the battery terminal and as a male contact for the auxiliary power cord receptacle without exposing the pin to damage from over-insertion of the battery into the battery cavity.

Abstract: This invention relates to a power supply that integrates a rectifier/filter's circuitry and a converter's circuitry with an inverter to reduce space occupied and increase power efficiency. The power supply includes: a rectifier/filter, a DC-DC converter and a DC-AC inverter. The rectifier/filter, connected to an alternating current (AC) input terminal, converts the input AC into a direct current (DC). The DC-DC converter and the DC-AC inverter are parallel to each other with one end concurrently connected to the rectifier/filter's output and the other end respectively outputting the desired powers. As such, DC-DC converter reduces the converted DC voltage to lower DC voltages to power all circuits except for the lamp and DC-AC inverter converts the converted DC voltage into higher AC voltage output to drive the lamp.

Abstract: A method and structure for electric power management that economically satisfies peak power demand and immediately satisfies a sudden substantial increase in power demand. An electric power management system comprises a first circuit element in parallel with a second circuit element, and a load in parallel with the first circuit element. The first circuit element includes a first direct current (DC) energy source in series with a first diode that prevents current backflow into the first energy source. The first energy source may comprise a conventional energy source such as fossil fuel, natural gas, hydroelectric power, etc. Alternatively, the first energy source may comprise an alternative energy source such as, inter alia, fuel cells, solar cells, wind power, and biomass power.

Abstract: A highly efficient fast charger for high capacity batteries and methods for fast charging high capacity batteries. The fast charger preferably comprises a rectified AC input of single or preferably three phases, with an optional power factor corrected input, minimally filtered with high frequency, high ripple current capacitors, which is switched with a power switching circuit in the “buck” configuration into an inductor/capacitor output filter. Metallized film capacitors are employed, to minimize the rectified 360 Hertz AC component filtering while providing transient switch protection and ripple current requirements for the buck regulator, to provide a high current fast charger with substantially improved power factor. High power, high frequency switching with minimized output filter size provides a highly filtered DC output. The fast charger is adapted to be constructed in a modular design for simple maintenance.

Abstract: A simple and flexible battery charger for charging high voltage battery strings includes a DC-to-AC converter that drives the primary of a transformer having multiple secondaries. Each secondary winding has a corresponding output stage formed of a rectification circuit, output inductor, and output capacitor. The output terminals of the output stages are connectable either in parallel or series. In either configuration, inductor current and capacitor voltage automatically balance among the output stage circuits. A controller normally regulates output terminal voltage by operating in voltage mode, but limits current by operating in a current mode when the average of inductor currents exceeds a specified limit. Reconfiguration from parallel to series, or vice versa, is obtained physical reconnection of the output stage terminals and adjustment of a single voltage feedback scaling factor.

Abstract: Disclosed herein is a hands-free kit for mobile phones using a solar cell. The hands-free kit has a solar cell, a charging unit, and a power switch. The solar cell is formed to be integrated with the body at a portion of the body of the hands-free kit and used to convert sunlight into electrical energy. The charging unit is formed at a portion within the body of the hands-free kit for charging one or more rechargeable batteries of the charging unit by power supplied from the solar cell. The power switch is formed at a portion of the body of the hands-free kit for allowing the rechargeable batteries to be connected in parallel with the solar cell and charged when the power switch is turned off, while allowing the rechargeable batteries to be connected in series with each other so as to convert a charged voltage into power for operating an internal circuit of the hands-free kit when the power switch is turned on.

Abstract: In an exemplary embodiment, a battery conditioning system monitors battery conditioning and includes a memory for storing data based thereon; for example, data may be stored representative of available battery capacity as measured during a deep discharge cycle. With a microprocessor monitoring battery operation of a portable unit, a measure of remaining battery capacity can be calculated and displayed. Where the microprocessor and battery conditioning system memory are permanently secured to the battery so as to receive operating power therefrom during storage and handling, the performance of a given battery in actual use can be accurately judged since the battery system can itself maintain a count of accumulated hours of use and other relevant parameters. In the case of a nonportable conditioning system, two-way communication may be established with a memory associated with the portable unit so that the portable unit can transmit to the conditioning system information concerning battery parameters (e.g.

Abstract: A DC-DC converter including a current error amplifier and a voltage error amplifier connected in parallel to control the charging phase of the battery, during which a charging current is supplied to the battery to bring the voltage of the battery gradually up to a full charge voltage; a charging interruption stage for interrupting the charging phase before the voltage of the battery has reached the full charge voltage; and an activation stage for activating the charging interruption stage when the full charge voltage is close to the supply potential at which the supply line of the current error amplifier is set.

Abstract: A DC-DC converter generally includes a supply circuit, a charge circuit, and a control unit connected to the charge circuit. The charge circuit receives the input current and supplying a charge current to the battery. The control unit controls the charge current according to the results of comparisons between various currents and voltages and corresponding threshold levels. The control unit, which may be constructed on a single-chip semiconductor substrate, includes a differential charge controller, a charge current controller, a charge voltage controller, and a dynamic charge controller. These elements respectively compare the input current, the charge current, the charge voltage and an input voltage from the external DC power supply with a threshold values and control the charge current and charge voltage according to a result of the comparisons.

Abstract: A single dual-voltage battery capable of powering an automobile system having electrical equipment that requires different supply voltage. The battery allows idle stop, assisted drive and regeneration to be performed more efficiently by cooperative control of a controller and a DC/DC converter. Commonly performed external powering and starting can also be carried out if the battery has expired. The single dual-voltage battery is obtained by equipping a 12-V battery with a 24-V battery of a different type and adapted to supply power to respective electrical components. The 12-V battery unit is provided with a charging controllable DC/DC converter or downverter. The ancillary battery condition is monitored and controlled. External powering and starting is facilitated by using an ultracapacitor as the ancillary battery. The battery can be used with a single relay.

Abstract: An analog/digital integrated subscriber circuit includes a power supply part supplying power with respect to a subscriber line, and a signal processing part carrying out a signal processing. The power supply part is provided with a D.C./D.C. converter which controls an ON-time of a switching by detecting an output voltage and an output current supplied to the subscriber line. The D.C./D.C. converter includes a switching mechanism for switching a power supply characteristic of the power supply part to a constant current characteristic up to a maximum output voltage when supplying the power with respect to a digital subscriber line and to a constant voltage characteristic having a voltage lower than the maximum output voltage when supplying the power with respect to an analog subscriber line.

Abstract: A far-distance remotely controllable rectifier with a back-up battery may be applied to any electric appliance that requires a rectifier, and particularly to a wireless phone or the like telecommunication equipment, to serve as an uninterrupted power supply. A replaceable and rechargeable back-up battery and a ring-controlled switch circuit are provided to the rectifier of this invention to keep the machine working in case of an unexpected failure of the civil power or in response to detection of a phone call from a far distance to a ring-controlled switch for effecting a continuous power supply. Under normal conditions, the civil power is used to charge the back-up battery as a stand-by power source.

Abstract: An uninterruptible power supply (UPS) comprises a low voltage converter (02); a coupled inductor (60) comprising a first inductor (63) coupled to the battery, a second inductor (61) coupled to a first output terminal of a rectifier, and a third inductor (62) coupled to a second output terminal of the rectifier; a snubber circuit; and a high voltage inverter (01).

Abstract: An autonomous low power consumption electrical apparatus that has a supply device (8) comprising a single photo-voltaic cell, an electrical accumulator (7), and a voltage booster (10, 11, TR1, TR3) connected between the power source (9) and the accumulator for charging the accumulator. The voltage booster is controlled by a pulse signal having a predetermined frequency. To allow the apparatus to start when the accumulator is completely discharged, the pulse signal can be generated, at least temporarily, by an oscillator that can operate at a very low voltage, that is, the voltage of the single photo-voltaic cell. When the apparatus is a timepiece, the oscillator (2) can be replaced by the oscillator of the time-keeping circuit (1) of the timepiece as soon as the accumulator (9) is sufficiently charged.

Abstract: Process and circuit layout for using an independent capacitor for the momentary retention of an output voltage when an input voltage is lost. To facilitate a reduction in capacitance in independent circuits of this type at a constant amount of charge, the input voltage is transformed by a DC/DC up converter to a higher capacitor voltage, which is stored in the independent capacitor and the capacitor voltage is transformed by a DC/DC down converter to the output voltage for the load element, which is less than the capacitor voltage. As the DC/DC down converter can utilize capacitor voltages until the output voltage is reached, the residual voltage remaining in the independent capacitor (C) is no longer used. The independent time interval is correspondingly short. According to the invention, the capacitor is disconnected from the output of the DC/DC up-converter and connected to its input when the input voltage is less than a reference voltage.

Abstract: A sealed rechargeable lithium-ion battery pack which includes a switching voltage regulator. The regulator uses the normal cutoff transistors as the switching devices, and also includes a discrete inductor in the battery pack. The regulator is operated with programmable voltage and current parameters, under control of a microcontroller which is also inside the sealed battery pack enclosure.

Abstract: A charging-and-discharging device in an electronic apparatus includes a rechargeable battery and a charging device for charging the battery. The charging-and-discharging device includes a switching circuit electrically isolating one terminal side of the battery from a ground side of the electronic apparatus. The charging-and-discharging device further includes a charge control section controlling the isolating of the one terminal side of the battery from the ground side of the electronic apparatus by turning off the switching circuit during charging of the battery. In the charging-and-discharging device, the one terminal side of the battery is isolated from the ground side of the electronic apparatus by the switching circuit during charging of the battery and a closed loop including the charging device and the battery is established to charge the battery.

Abstract: A magnetic sensing circuit is arranged in cooperative relation to a flyback transformer in a capacitor charging circuit for directly sensing the state of the transformer magnetic field for controlling the switching of power to the primary winding of the flyback transformer. A first threshold is sensed when the flyback transformer is nearly saturated with magnetic energy storage. A second threshold is sensed when all of the magnetic energy stored in the flyback transformer has been transferred to the capacitor. The sensed thresholds are used to optimally control the switching of power to the primary winding to maximize the efficiency and minimize the charging time of the capacitor charging circuit. A capacitor charging circuit which utilizes the present invention can be part of an implantable cardioverter defibrillator.

Abstract: An electric power recovering system includes a switch disposed between a battery and a coil, and two diodes coupled between the coil and the battery. A capacitor is coupled between the diodes and is grounded. The switch is alternatively actuated either manually or by an alternatively actuating device for allowing the coil to generate a high voltage and for allowing the coil to charge the battery. A DC/DC converter is further coupled between the battery and the switch for providing an increased electric power.

Abstract: A dual mode battery charger includes an input that accepts a DC power signal, and a switch that switches the DC power signal from the input responsive to a control signal to generate a charging signal for the battery. A dual mode controller generates the control signal so that during a high current charging mode the switch is closed, and so that during a low current charging mode the switch is switched at a duty-cycle of less than 100 percent. In addition, a filter filters the charging signal to reduce a ripple portion thereof. Related methods and electronic devices are also discussed.

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: In a self-oscillating power-supply circuit for charging a battery (B) the switching transistor (T2) is turned off if the voltage across the sensing resistor (R3) exceeds the threshold voltage of a zener diode (D5). Instead of the zener diode (D5) it is possible to use a switching transistor which is actuated when the current through the switching transistor exceeds a given value. A diode (D6) is arranged in series with the zener diode (D5) and can be short-circuited by means of a switch (T3) in order to switch the power-supply circuit from slow charging to rapid charging. A voltage sensor may be added to monitor the battery voltage and to eliminate the short-circuit of the diode (D6) when a given battery voltage is reached, as a result of which the power-supply circuit changes over to slow charging.

Abstract: In a self-oscillating power-supply circuit for charging a battery, the main switching transistor is turned off by a second switching transistor (T2) of an opposite conductivity type, which is arranged in series with the main switching transistor (T1) via a sensing resistor (R8). This configuration allows rapid switching of the main switching transistor (T1). The power-supply circuit can be turned on and off in a simple manner (R7, T4). Moreover, it is simple to provide a compensation (R4) for varying mains voltages, an auxiliary voltage (D6, C4) for powering additional circuits (R9, R10), which auxiliary voltage also remains available when the power-supply circuit is turned off.

Abstract: A low cost load sensing technique that is suitable for use in sensing batteries in a battery charging circuit is disclosed. The circuit is adapted to be utilized in conjunction with a power supply which may include a primary converter and a voltage feedback circuit. A transformer with a dual secondary winding is connected between the primary converter and the output terminals of the charging circuit. When no load or battery is present, a first feedback loop is utilized with both of the secondary transformer windings in series, which supplies a constant output voltage at the output terminals. When a load is present, a second feedback loop is utilized which includes one of the secondary windings to provide the voltage of the output terminals. A capacitor is connected in parallel with the other secondary winding. When a load is present, a step increase in voltage occurs across the capacitor due to the fact that the both secondary windings are in phase when a load is present.

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: A method of charging and/or transferring charge between a multiplicity of accumulators connected in series, the method includes connecting at least one electrical storage device in parallel to the accumulators on a cyclic basis. The electrical storage devices are made up of transformer elements which are charged by the accumulators. During charging operations, the at least one electrical storage device is switched, on a cyclic basis, as the secondary coil of a transformer, a powered coil wound on the same core acts as the primary coil. During charge-transfer operations, the at least one electrical storage device is switched, on a cyclic basis, as a transmission coil in which a voltage is induced from the whole battery of accumulators, or one or more individual accumulators.