International Components Corporation

Icc-nexergy, Inc.

Li Wen Hua

Robert F Wentink

Huang Tai Guang

Xia Ju Jie

Brian Scott Gaza

Haung Tai Guang

Jian Fei Liu

A multiple cell battery charger with a parallel topography is disclosed which requires fewer active components than known battery chargers and protects the battery cells from overcharge and discharge. The charger that includes a regulator for providing a regulated source of direct current (DC) voltage to the battery cells to be charged. Each battery cell is connected in series with a switching device, such as a field effect transistor (FET) and optionally a current sensing device. In a charging mode, the serially connected FET conducts, thus enabling the battery cell to be charged. Battery voltage is sensed by a microprocessor. When the microprocessor senses that the battery cell is fully charged, the FET is turned off, thus disconnecting the battery cell from the circuit. Since the battery cell is disconnected from the circuit, no additional active devices are required to protect the battery cell from discharge.

Multiple cell battery charger configured with a parallel topology

A multiple cell battery charger configured with a parallel topography is disclosed. In accordance with an important aspect of the invention, the multiple cell battery charger requires fewer active components than known battery chargers while at the same time protecting multiple battery cells from overcharge and discharge. The multiple cell battery charger in accordance with the present invention is a constant voltage battery charger that includes a regulator for providing a regulated source of direct current (DC) voltage to the battery cells to be charged. In accordance with the present invention, each battery cell is connected in series with a switching device, such as a field effect transistor (FET) and optionally a current sensing device. In a charging mode, the serially connected FET conducts, thus enabling the battery cell to be charged. The battery voltage is sensed by a microprocessor. When the microprocessor senses that the battery cell is fully charged, the FET is turned off, thus disconnecting the battery cell from the circuit. Since the battery cell is disconnected from the circuit, no additional active devices are required to protect the battery cell from discharge. As such, a single active device per cell, such as the FET, provides multiple functions without requiring additional devices. Accordingly, the battery charger in accordance with the present invention utilizes fewer active components than known battery chargers and is thus much less be expensive to manufacture.

A rapid charging circuit for a lithium ion battery. The battery charger in accordance with the present invention compensates for the voltage drops across the various resistance elements in the battery circuit by setting the charging voltage to a level to compensate for the initial resistance of the series resistances in the circuit and an additional resistance selected to take into account the anticipated increase in resistance of the various circuit elements over time. The battery charger in accordance with the present invention periodically monitors the open-circuit voltage of the battery cell and reduces the charging voltage to when the battery cell voltage reaches the optimal value. Thus, during a constant current charging mode, the battery cell is driven at a relatively optimal charging current to reduce the charging time. As such, the system is able to optimize the charging current supplied to a battery cell during a constant current mode of operation while compensating for circuit elements whose resistance may vary over time due to temperature or other factors, such as corrosion, while at the same time avoiding exceeding the maximum recommended voltage for the battery cell.

Rapid charge lithium ion battery charger

A protection circuit for a wind turbine generator that includes a PWM Brake that works in conjunction with known Brake Relays is disclosed. The Brake Relay is used to short the generator output terminals at a first threshold voltage. The PWM Brake includes one or more switching devices, coupled across the generator output. The PWM Brake is under the control of a PWM Brake Control Circuit which actuates the PWM Brake at a second threshold voltage that is relatively lower than the first threshold voltage. In accordance with an important aspect of the invention, the PWM Brake Control Circuit includes a novel speed sensing circuit for providing a signal representative of the speed of the turbine generator The novel speed sensing circuit eliminates the need to mount a speed sensor on the pole top mounted turbine generator. As such, the need for adding cabling from the pole top mounted wind turbine generator is eliminated. The novel speed sensing circuit provides a signal representative of the rotational speed of the turbine generator based upon the duty cycle of a pulse width modulated (PWM) signal that is derived from the drive signal developed by the PWM Control Circuit. This signal is used to alternatively actuate and close the Brake Relay to minimize actuation of the centrifugal switch.

Speed sensing circuit for a wind turbine generator

A multiple cell battery charger configured in a parallel topology provides constant current charging. The multiple cell battery charger requires fewer active components than known serial battery chargers, while at the same time preventing a thermal runaway condition. The multiple cell battery charger in accordance with the present invention is a constant voltage constant current battery charger that includes a regulator for providing a regulated source of direct current (DC) voltage to the battery cells to be charged. The battery charger also includes a pair of battery terminals coupled in series with a switching device, such as a field effect transistor (FET) and optionally a battery cell charging current sensing element, forming a charging circuit. In a charging mode, the serially connected FET conducts, thus enabling the battery cell to be charged. The FETs are controlled by a microprocessor that monitors the battery cell voltage and cell charging current and optionally the cell temperature. The microprocessor periodically adjusts the charging current of each cell to maintain a relatively constant current. When the microprocessor senses a voltage or temperature indicative that the battery cell is fully charged, the FET is turned off, thus disconnecting the battery cell from the circuit. Accordingly, the battery charger in accordance with the present invention utilizes fewer active components and is thus less expensive to manufacture than known battery chargers configured with a serial topography while at the same time providing constant current charging to avoid a thermal runaway condition.

Pseudo constant current multiple cell battery charger configured with a parallel topology

A battery charger with a discrete switched regulator provides relatively high efficiency and relatively low cost. Unlike known battery chargers which incorporate switched regulator ICs, the battery charger in accordance with the present invention utilizes the microprocessor for a dual function. In particular, the microprocessor not only controls the charging characteristics of the battery charging circuit but also directly controls the power output of the battery charger by direct control of the discrete switched regulator circuit. By using a discrete switched regulator circuit and redefining the role of the microprocessor, the battery charger in accordance with the present invention is relatively less expensive than known battery chargers which incorporate switched regulator ICs.

Battery charger with dual use microprocessor

A battery charger that is configured to charge different size battery cells and automatically determine the size of the battery cell to be charged. The battery charger includes at least one charging circuit and a microprocessor. The charging circuit, in turn, includes a serially connected switching device and a current sensing resistor and a first and second pair of battery terminals that are configured to receive different size battery cells. The first pair of battery terminals is serially connected to a size detection resistor. The serial combination of the first pair of battery terminals and the size detection resistor is connected in parallel with a second pair of battery terminals. The parallel combination is connected in series with the charging circuit. At a nominal charging current, the voltage at the battery terminals will vary by the voltage drop across the size detection resistor. Accordingly, by measuring the voltage at the battery terminals, the system can determine which pair of battery terminals is connected to a battery cell. By configuring the first pair of battery terminals to receive a first battery cell size, for example, size AAA, and serially coupling the first pair of battery terminals to the size detection resistor, and configuring the second pair of battery terminals to receive a second size of battery cell, for example, size AA, the battery cell size can easily be detected electronically by measuring the voltage at the battery terminals.

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Huayang Town, China

Li Wen Hua