Abstract: A current measurement device is configured to measure electrical current in a primary conductor that is electrically insulated from the current measuring device. The current measuring device includes a transformer with a saturable magnetic core formed with a central aperture and a current measuring circuit. The electrical conductor in which electrical current is to be measured is disposed in the central aperture of the magnetic core. The current measuring circuit includes a current source driven by a voltage ramp generator that is connected to the secondary winding in a direction opposite the flow of electrical current in the primary conductor. When the magnetic flux in the transformer core is equal and opposite the magnetic flux generated as a result of the electrical current flowing in the primary conductor, the voltage of the voltage ramp generator is representative of the DC or AC electrical current flowing in the primary conductor.

Abstract: The resistors R1 and R2 are applied to terminals 1 and 8, respectively, of the switched-mode power supply 26. These resistors R1 and R2 are current-limiting resistors and function to control the output power and current. A standard buck regulator may be coupled to terminal 5 of the switched-mode power supply 26. The buck regulator includes a diode D7 and an inductor L1. The diode D7 and inductor L1 provide DC rectification and filtering of the high-frequency switch voltage from the switched-mode power supply 26.

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 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 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: 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 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 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 charge termination circuit which may be disposed within the battery cell pack and used in conjunction with known battery safety circuits to protect against charging conditions which reduce the life of a battery cell. In particular, the charge termination circuit is adapted to be used in conjunction with an off the shelf battery safety circuit and one or more power FETs coupled between the battery cell and the battery charger terminals on the battery cell package. The charge termination circuit includes a microcontroller and monitors the battery cell voltage by way of an I/O part and activates a first timer anytime the charging current to the battery is below a predefine threshold, for example, indicative of a maintenance or trickle charge. When the first timer times out after a predetermined time period, for example, two hours, the charge termination current forces the one or more of the serially coupled FETs switches to interrupt battery charging of the battery cells.

Abstract: A pivotable electrical plug assembly includes a pair of elongated blades, such as rod shaped European style blades. A detent mechanism is formed with electrically conductive resilient members for releasably retaining rear portions of the elongated blades, for example, European rod shaped blades. The plug assembly is pivotally mounted to an appliance housing, such as a consumer electronic appliance or device, with the resilient members being mounted in fixed position relative to the appliance housing. The resilient members are adapted to extend into the appliance housing to engage the blades without requiring any modifications to the standard blade design.

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: A modular battery system for a portable device including a charging module with a retractable plug and charging circuit for converting an AC line voltage to a DC battery charging current. The charging module combines with a battery module and optional fuel gauge (if present) to form a single unit for recharging, preconditioning the battery, and connection to the portable device. The modules are releasably connected, preferably involving conductive fasteners, so that a user may connect a new battery module to an old charging module. The releasable connection serves as both the mechanical and the electrical interface between the battery module and the charging module. The conductive fasteners may be located in different positions on the modules to accommodate different connector geometries. The charging module may also combine with a battery mounting module, rather than the battery module, so that the system works with conventional battery packs.

Abstract: A submersible pump with an on/off switch electrically connecting a rechargeable battery to the motor. An upper sealable compartment contains the battery, recharging connections, and switch with inward projections to position the battery, a recharging receptacle for the battery on the top of the upper compartment, a resilient cover sealing the switch while permitting actuation of the switch from outside of the upper compartment, and a cap sealing the recharging receptacle. A lower compartment houses the motor, pumping chamber, and impeller. A bullet-shaped shell is seated in the lower compartment with a sealing ring between the shell and lower compartment. The motor is disposed in the shell with the motor drive shaft projecting through an opening in the tip of the shell and another seal surrounds the drive shaft between the motor and tip of the shell.