14880 results about "Dynamo" patented technology

An electrosurgical generator for supplying RF power to an electrosurgical instrument for cutting or vaporising tissue has an RF output stage (42) with an RF power bridge (Q1, Q2, Q3, Q4), a pair of output lines (74) and a series-resonant output network (48). The output impedance of the output stage (42) at the output lines (74) is less than 200/√P ohms, where P is the maximum continuous RF output power of the generator. The generator offers improved cutting and vaporising performance, especially in relation to the reliability with which an arc can be struck when presented with an initial low impedance load. Overloading of the output stage is prevented by rapidly operating protection circuitry responsive to a predetermined electrical condition such as a substantial short-circuit across the output lines. In the preferred embodiment, the output stage is capable of maintaining output pulses at least 1kW peak by supplying the power bridge from a large reservoir capacitor (60). Pulsing is dynamically variable in response to load conditions by controlling the maximum energy per pulse in response to the reservoir capacitor voltage.

A method for calculating the capacitance of a transducer (C₀) without knowing the exact resonance frequency of a transducer/blade combination is achieved by sweeping across a broad frequency range which contains resonant and non-resonant frequencies where C₀ can be measured. A pre-defined frequency range is set independently of the resonance frequency of a specific transducer/blade combination. C₀ of the transducer/blade is measured at several different frequencies within the pre-defined frequency range to ensure that invalid C₀ measurements are disregarded, and the temperature of the transducer is calculated based on valid C₀ measurements. The determined transducer temperature, based on C₀ measurements, can be used to optimize performance and/or provide a safety shutdown mechanism for the generator.

A method and circuit for determining the speed and/or counting the revolutions of brush and commutator motors is described. The method and circuitry detects signals present on the windings of the motor due to commutation that occurs at the brushes and commutator of the motor. This method can be used to simply monitor & indicate the motor speed and revolutions or to form the basis of a motor control.

An implantable pulse generator includes a current steering capability that allows a clinician or patient to quickly determine a desired electrode stimulation pattern, including which electrodes of a group of electrodes within an electrode array should receive a stimulation current, including the amplitude, width and pulse repetition rate of such current. Movement of the selected group of electrodes is facilitated through the use of remotely generated directional signals, generated by a pointing device, such as a joystick. As movement of the selected group of electrodes occurs, current redistribution amongst the various electrode contacts takes place. The redistribution of stimulus amplitudes utilizes re-normalization of amplitudes so that the perceptual level remains fairly constant. This prevents the resulting paresthesia from falling below the perceptual threshold or above the comfort threshold.

A circuit is disclosed which minimizes the amount of tissue vaporized during a first half (positive half cycle) of an electrosurgical current cycle and minimizes the amount of current applied to tissue during a second half (negative half cycle) of the electrosurgical current cycle to control thermal spread. The circuit is preferably provided within an electrosurgical generator which is capable of controlling the amount of energy delivered to a patient during electrosurgery on a per arc basis.

A self-powered medical device, for example a pacemaker uses the variations of blood pressure inside the heart or a major artery to create a mechanical resonance in an electromagnetic or piezoelectric generator. The resonance extends the time power is generated during the cardiac cycle. The pressure variations compress a bellows carrying the resonant generator. The inside of the bellows may be evacuated to a partial or full vacuum, and a spring restores the bellows to the desired equilibrium point, acting against the blood pressure. The current pulses are stored in a capacitor. Eliminating the battery allows dramatic miniaturization of the medical device to the point it can be implanted at the point of desired stimulation via a catheter.

The subject matter of the present invention is a method for monitoring a photovoltaic generator (1) for generating current with a number of solar cells connected between two external connections by repeated feeding of a current with a frequency spectrum into the generator current circuit, detecting thereby a respective frequency response in the frequency spectrum with the supplied current as the input variable and an electric variable of the generator as the output variable, and detecting a change in the frequency response for monitoring the photovoltaic generator (1) in the event of a change during repeated feeding.

An adaptive electric car or other vehicle with potentially better performance—power, efficiency, range—than a gasoline vehicle, at a competitive cost. The motor control system can dynamically adapt to the vehicle's operating conditions (starting, accelerating, turning, braking, cruising at high speeds) and other inputs and parameters. That consistently provides better performance. Isolating the vehicle's motor or generator electromagnetic circuits allows effective control of more independent parameters. That gives great freedom to optimize. Adaptive motors and generators for an electric vehicle are cheaper, smaller, lighter, more powerful, and more efficient than conventional designs. An electric vehicle with in-wheel adaptive motors delivers high power with low unsprung mass and high torque and power-density. Total energy management of the vehicles entire electrical system allows for large-scale optimization. An adaptive architecture improves performance of a wide variety of vehicles, particularly those that need optimal efficiency over a range of operating conditions.

There is provided herein methods and apparatus for apparatus for controlling the interconnection of an auxiliary AC generator with an electrical system, such as an electrical distribution system, e.g., a utility grid. A measuring circuit measures the frequency of an auxiliary AC generator and the phase angle between one voltage phase of the generator and the correspondent voltage phase of the electric utility's electricity supply lines, i.e., the grid, each of which are averaged and filtered. The measured frequency of the auxiliary AC generator is matched to the frequency of the electrical system and the measured phase angle of the generator is matched to the electric utility's electricity supply lines. Once matching is achieved to within a defined tolerance, interconnecting contactors are closed.

The invention relates to a conditioning circuit that measures operating points of a power supply to deduce therefrom the current-voltage characteristic thereof and to determine directly the voltage corresponding to its maximum power point, without using any kind of tracking algorithm that causes the operating point of the power unit to oscillate about the maximum power point. The maximum power point voltage VMPP is supplied to a controller which regulates a power cell by slaving it to the input voltage until the output voltage of the supply is equal to the maximum power point voltage V_MPP. The invention also relates to a solar generator and an associated conditioning method. One particular application is to high-power satellites.

The invention relates to a device for measuring current in an inductor, which device is intended to be connected in parallel with said inductor, comprising two terminals A and B. The device comprises: a network in parallel with the inductor and connected to the terminals A and B having a resistor R2 in series with a resistor R1 in parallel with a capacitor C1; a voltage offset circuit having a DC voltage generator E connected in parallel with an offset resistor (Roffset) in series with two resistors in parallel R3 and R4, the positive pole of this voltage source being connected to terminal B of the inductor; a temperature compensation circuit comprising a current source controlled as a function of the temperature, one of the two terminals of the current source being connected to the negative pole of the generator E, the other terminal of the current source being connected to different points of the measurement device according to the direction of variation of the current of the source as a function of the temperature. The measurement of voltage Vmes, the image of the current I in the inductor 12, is performed between the common point between the resistors R1, R2 of the network and the common point between the offset resistor and the two resistors R3 and R4.

Apparatuses and methods for configuring and managing solar panels to form strings of photovoltaic energy generators with improved performance and reduced cost. The photovoltaic energy generators are connected via one or more combined local management units (CLMUs), each having a plurality of direct current converters connected to and configured to receive direct current power from a respective solar panel. A controller unit shared by the CLMU's direct current converters is utilized to separately control the operation of each converter such that the power extracted from the solar panels is maximized. A communications unit coupled with the controller unit is utilized to facilitate communications between the controller unit and a system unit remote from the CLMU to report measurements and receive control signals.

A system that couples distributed power generators together as a collective unit for the purposes of selling or purchasing energy from the electrical power grid. The apparatus includes a charge/discharge controller and an adaptive controller. The charge/discharge controller transfers energy generated by the plurality of distributed power generators to the power grid. The adaptive controller directs when the charge/discharge controller transfers energy generated by at least one of the plurality of distributed power generators to the electrical grid.

An AC generator for a vehicle including a rotor with a fan, a stator disposed around the outer periphery of the rotor, and a frame. The stator includes a laminated core having a plurality of slots, a plurality of electric conductors in the slots, and an insulator. There is a gap between the electric conductors and the insulator in a diametrical section of the slots, and an area ratio of the gap with respect to the sectional area of the slots is not more than 25%. A portion of the electric conductor positioned within the slot has a substantially rectangular shape along the shape of the slot.

A method of finding a power maximum of a photovoltaic generator using an MPP regulator of a photovoltaic current converter by means of which a maximum generator power is set at an operating point of the generator's characteristic curve is intended to supply improved efficiency when the generator is partially shadowed. This is achieved by switching the MPP regulator off in order to next load and/or unload the generator to allow a new operating point of the generator's characteristic curve to set and by next switching the MPP regulator on again.

The Smart Generator of the present invention allows the designer/developer/user to model the EJB components in a natural way without being concerned with implementation-specific details. The developer models the business objects using a UML drawing tool and the Smart Generator creates a set of classes that implements these objects with reference to the Enterprise JavaBeans specification. That is, the Smart Generator automatically create access methods and handling containment of references from the UML diagram.

The present invention provides a power converter that can be used to interface a generator that provides variable voltage at variable frequency to a supply network operating at nominally fixed voltage and nominally fixed frequency and including features that allow the power converter to remain connected to the supply network and retain control during supply network fault and transient conditions. The power converter includes a generator bridge electrically connected to the stator of the generator and a network bridge. A dc link is connected between the generator bridge and the network bridge. A filter having network terminals is connected between the network bridge and the supply network. A first controller is provided for controlling the operation of the semiconductor power switching devices of the generator bridge. Similarly, a second controller is provided for controlling the operation of the semiconductor power switching devices of the network bridge. The first controller uses a dc link voltage demand signal VDC_NET* indicative of a desired dc link voltage to control the semiconductor power switching devices of the network bridge to achieve the desired level of dc link voltage that corresponds to the dc link voltage demand signal VDC_NET*. The second controller uses a power demand signal P* indicative of the level of power to be transferred from the dc link to the supply network through the network bridge, and a voltage demand signal VTURB* indicative of the voltage to be achieved at the network terminals of the filter to control the semiconductor power switching devices of the network bridge to achieve the desired levels of power and voltage that correspond to the power and voltage demand signals P* and VTURB*.

A tethered airborne electrical power generation system which may utilize a strutted frame structure with airfoils built into the frame to keep wind turbine driven generators which are within the structure airborne. The primary rotors utilize the prevailing wind to generate rotational velocity. Electrical power generated is returned to ground using a tether that is also adapted to fasten the flying system to the ground. The flying system is adapted to be able to use electrical energy to provide power to the primary turbines which are used as motors to raise the system from the ground, or mounting support, into the air. The system may use an attachment mechanism for the tether adapted to move the tether attachment point relative to the flying craft.

A method of controlling output power of an electrosurgical generator apparatus that controls a variable output signal to a pair of electrodes includes setting the output power of the generator apparatus to a selected power output level. An impedance is measured across the electrodes when the electrodes are applied to an area of tissue. The output power of the generator apparatus is changed to a boost power output level greater than the selected power output level. The boost power output level corresponds to a calculation based at least in part on the measured impedance. The method further includes applying the output signal to the electrodes at the boost power output level for a first time duration and changing the power output to the selected power output level after the first time duration. An electrosurgical generator apparatus operating in accordance with the method is also described.