571 results about "Voltage polarity" patented technology

A state of charge indicator includes a current sensing circuit for sensing and converting charge or discharge current of a battery into a bipolar voltage. A counter circuit counts battery charge. A charge/discharge circuit is operatively connected to the current sensing and counter circuits and detects the voltage polarity from the current sensing circuit and sets the counter circuit to a count mode with an up or down count for a respective charge or discharge. A reset circuit is operative with the current sensing circuit, counter circuit and charge/discharge circuit for resetting the counter circuit to an actual state-of-charge of the battery after delay when the battery is idle representative of a battery open circuit voltage.

A programmable metallization cell ("PMC") comprises a fast ion conductor such as a chalcogenide-metal ion and a plurality of electrodes (e.g., an anode and a cathode) disposed at the surface of the fast ion conductor and spaced a set distance apart from each other. Preferably, the fast ion conductor comprises a chalcogenide with Group IB or Group IIB metals, the anode comprises silver, and the cathode comprises aluminum or other conductor. When a voltage is applied to the anode and the cathode, a non-volatile metal dendrite grows from the cathode along the surface of the fast ion conductor towards the anode. The growth rate of the dendrite is a function of the applied voltage and time. The growth of the dendrite may be stopped by removing the voltage and the dendrite may be retracted by reversing the voltage polarity at the anode and cathode. Changes in the length of the dendrite affect the resistance and capacitance of the PMC. The PMC may be incorporated into a variety of technologies such as memory devices, programmable resistor/capacitor devices, optical devices, sensors, and the like. Electrodes additional to the cathode and anode can be provided to serve as outputs or additional outputs of the devices in sensing electrical characteristics which are dependent upon the extent of the dendrite.

An apparatus, method and system are disclosed for supplying power to a load such as a plurality of light emitting diodes. An exemplary apparatus comprises a primary module, a first secondary module couplable to a first load, and a second secondary module couplable to a second load. The primary module comprises a transformer having a transformer primary. The first secondary module comprises a first transformer secondary magnetically coupled to the transformer primary, and the second secondary module comprises a second transformer secondary magnetically coupled to the transformer primary, with the second secondary module couplable in series through the first or second load to the first secondary module. When energized by a power source, the first secondary module has a first voltage polarity and is couplable in a series with the first load configured to have an opposing, second voltage polarity, which substantially offset each other to provide a comparatively low resultant voltage level.

The present invention provides method and system for data communication in the human body and a sensor therefor. The method and system transmit information through the human body to a receiver located outside the human body using low current and voltage polarity, so that they cause no damage to the human body and achieve low power consumption and better receiving sensitivity. In addition, the sensor contains a CMOS image sensor on which all circuits are integrated without radio transmitter and antenna, so that it achieves a low-priced and small-sized capsule type endoscope.

A transformer separable/detachable between a primary winding and a secondary winding, has a capacitor connected parallel to the secondary winding. A high-frequency AC voltage supplied to the primary winding of the transformer generates an induced voltage in the secondary winding. The secondary winding transmits electrical power to a load in non-contact manner. Either the output voltage remains constant as the output current varies, or vice versa. Taking as a first condition a fact that at the time of a maximum load, the time of the reversal of the voltage polarity of the primary winding substantially coincides with the time when an oscillating voltage of the capacitor reaches a maximum or minimum value. Taking as a second condition a fact that at the time of a minimum load, the time of the reversal of the voltage polarity of the above-mentioned primary winding substantially coincides with the time when the oscillating voltage of the above-mentioned capacitor completes one cycle. The capacitance of the capacitor is selected to satisfy simultaneously the first and second conditions. This allows the load voltage to remain constant in a load current range from a minimum to a maximum without requiring a feedback circuit.

Presented is a method of operating a capacitive microfabricated ultrasonic transducer (cMUT) array with multiple firings of varying bias voltage polarity patterns to improve its performance in imaging non-linear media, such as in contrast agent imaging or tissue harmonic imaging. Additionally, transducers incorporating the method are provided. The method of cMUT operation and the corresponding cMUT does not require pre-distortion or phase inversion of the transmit signal and can achieve an improvement in the elevation focus of the cMUT, as compared to the elevation focus that a single firing can achieve. Further, the method of operating the cMUT minimizes the deleterious effects that result from insulators being subjected to high electric fields.

A method of driving a display panel in which a voltage polarity reverse cycle of a data signal is three or more scan periods, and multiple scan lines are driven by switching between a first and a second scan orders by a predetermined period. The method includes setting a display pattern as a first maximum current pattern, the display pattern in which the multiple scan lines are driven in the first scan order and a number of charge and discharge of the data signal becomes a maximum number, and specifying that the number of charge and discharge of the data signal when displaying the first maximum current pattern in the second scan order is to be ½ of that of the data signal when displaying the first maximum current pattern in the first scan order. Further, the voltage polarity reverse cycle for specifying the first and the second scan orders is one frame period.

A bridgeless power factor correction converter is configured such that a gate driver controls the ON ratio of a booster converter switch so that the ON ratio is gradually increased from 0, i.e., performs soft start control, every time the voltage polarity of an AC input in a totem-pole bridgeless power factor converter (TPBL converter is inverted) is inverted.

A method for selecting wire of single phase earthing in neutral point noneffective earthing system includes making instant short circuit between neutral point and ground at position near two ends voltage polarity from positive to negative over zero by short circuiter set between neutral point and ground when single phase earthing is occurred in neutral point noneffective earthing system and state is stabilized in order to generate a short circuit pulse current being used to judge earthing line through short circuit detector. The device for realizing said method is also disclosed.

A motor drive control device and motor startup method prevent startup noise and reduce startup time. At startup, a current to which a rotor does not react is passed through two phase coils of a polyphase DC motor in succession, and a voltage polarity induced in a non-conducting phase is detected. A first operation decodes the detected signal, and determines phase coils of the motor through which a current should pass to rotate the rotor and the energization direction. A second operation forms a control signal for passing a current according to the determination to drive the motor, detects a voltage peak induced in the non-conducting phase during the drive, and performs switching control of a conducting phase. In normal operation, the position of the rotor is detected based on a back EMF in each phase, and rotation control is performed.

An integrated circuit (IC) has logic and timing circuits that are coupled to discrete circuitry to provide protection and indications whenever an AC adapter that is faulty or has improper voltage levels or polarity are plugged into a system. In particular, the IC device provides over-voltage, under-voltage, and reversed-polarity protections to an electronic system to keep the electronic system from being damaged by an alternating current (AC) adapter having an improper voltage range or voltage polarity. It also provides a protection that prevents an adapter from powering a host system that has a short-circuit fault.

Embodiments of the present invention relate to independently switched inductors in a voltage converter. Each voltage transforming inductor of a voltage converter may be deignated a switch or bridge at each opposing terminal. The function of these switches is to periodically reverse the polarity of voltage across the inductors. By configuring independently switched inductors in series, the frustration of voltage tolerance limitations of the switches is mitigated.

A method and current sensor arrangement for measurement of a primary current in a primary conductor which is magnetically coupled to a secondary conductor via a ferromagnetic core, with a voltage of a specific amplitude being applied to the secondary conductor, such that a secondary current flows for remagnetization of the ferromagnetic core, and the secondary current is measured during the remagnetization of the core, in order to obtain a first measured value. The voltage polarity is then reversed such that a secondary current flows for renewed remagnetization of the ferromagnetic core, and the secondary current is measured during the remagnetization of the core, in order to obtain a second measured value. The primary current is calculated as a function of the first and of the second measured value, with the polarity reversal being carried out at least once at a time which occurs before that time at which the ferromagnetic core reaches its saturation magnetization.

The invention discloses a trigger for triggering a Trigatron gas switch. The trigger comprises a pulse high-voltage generation part and a pulse current generation part which are connected in parallel; the pulse high-voltage generation part and the pulse current generation part are connected through a blocking capacitor and a magnetic switch; and when the trigger works, the trigger firstly outputs pulse voltage and then outputs pulse current. When the trigger works, pulse trigger voltage firstly acts on a trigger gap of the Trigatron gas switch, and the pulse current generation part supplies energy for generating discharge and maintaining plasma after the trigger gap is punctured by the pulse high-voltage. The output voltage polarity, a parameter of a pulse transformer and a parameter of the pulse current generation part of the trigger can be adjusted as required.

The invention discloses a hybrid direct-current transmission topology structure and a control method. The hybrid direct-current transmission topology structure is characterized in that two groups of thyristor converters are connected in series to form a first converter station, two groups of voltage source type converters are connected in series to form a second converter station, switch elements are respectively mounted at the same positions of the positive ends and the negative ends of the converters, in series connection, of the first converter station or the second converter station or the first converter station and the second converter station, and meanwhile, the same positions of the positive ends and the negative ends of the converters are in parallel connection and crossly connected to the opposite ends through one switch element respectively. The control method includes reducing direct-current power of a direct-current system to zero, and changing states of the switch elements to invert voltage polarity of the direct-current system, thereby achieving overall operation of two poles after inversion of the direct-current voltage polarity or achieving new two-pole direct-current operation by means of crossing of the converters in series connection of the converter stations at both ends. The system of the hybrid direct-current transmission topology structure has advantages of low manufacturing cost as the conventional direct-current transmission and control flexibility as the flexible direct-current transmission, and the like.

The invention discloses a pixel unit, a pixel structure, a display device and a pixel driving method to solve the problem of high power consumption caused by the fact that data signals inputted into each data line require voltage change in the prior art. Positions of pixel electrodes and public electrodes in each two adjacent pixels of a pixel unit using the dual-grid technique are changed in the pixel unit, the pixel structure is formed by an array consisting of the pixel units, and the pixel driving method corresponding to the pixel structure is provided, so that changing of voltage polarity of data signals inputted into each data linen is not needed during point turning or column turning of pixels, and power consumption is reduced.