Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An over speed control circuit for a wind turbine generator is disclosed which optimizes the time that the wind turbine generator is operational and thus maximizes the power output over time. The over speed control circuit forms a closed feedback loop which periodically measures the output voltage of the wind turbine generator in order to regulate its speed by electronically controlling the load on the generator. The over speed control circuit in accordance with the present invention is adapted to work in conjunction with known over speed protection lock out relays. More particularly, the over speed control circuit causes a short circuit to be placed the generator terminals when the generator voltage reaches a threshold value, relatively less than the threshold value used to trigger the over speed lockout relay.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A housing for a Cigarette Lighter Adapter (CLA) or accessory adapter plug facilitates insertion of the plug into a CLA or accessory adapter receptacle. In one embodiment of the invention, the housing is formed in a generally cylindrical shape with an expanded diameter portion defining a gripping portion which facilitates the gripping of the device. The housing may be used to house circuitry for a battery charger and include an indicator light to indicate the state of charge of the battery being charged.

Abstract: A relatively simple system sensing a nearly full state of charge of a battery, such as a lithium ion battery, and providing a visual indication of the nearly full state of charge. The system for measuring the state of charge relies on the charging characteristics of a lithium ion battery. In particular, the system measures the charging current to the battery. When the charging current drops to a level representing, for example, 80% or more of full charge, a visual indication is provided to indicate a near full charge state of the battery.