3116 results about "Volt" patented technology

An apparatus for controlling the speed of an AC motor comprising a switch adapted to be coupled in parallel with power terminals for the AC motor; a capacitor coupled in series with the parallel combination of the switch and the motor; the capacitor adapted to provide an AC supply voltage from an AC source to the parallel circuit comprising the motor and the switch; and a control circuit for controlling the conduction time of the switch in order to vary the speed of the motor. The switch is preferably pulse-width modulated at a frequency twice the line frequency of the AC supply voltage, and the switch is turned on when the voltage across the AC motor is zero volts. The apparatus is operable to provide for continuously variable control of the motor speed while minimizing acoustic noise in the motor.

A surgical system and associated method for sealing the passageway of a fluid-carrying vessel with a diameter up to 5 millimeters comprises an electrosurgical generator capable of delivering electrosurgical power, a surgical instrument electrically connected to the electrosurgical generator and adapted to transfer electrosurgical power from the electrosurgical generator to a pair of end effectors disposed at a distal end of the surgical instrument. The system also includes a power control circuit for controlling the delivery of radio frequency energy to the vessel through the end effectors, wherein the delivery of the radio frequency energy to the vessel comprises, raising the output current to a range below 1.75 Amperes RMS and the output voltage to a range below 135 Volts RMS. Radio frequency energy is applied to the vessel for a period of time while the power is held approximately constant. The flow of radio frequency energy is terminated when the impedance of the vessel being sealed reaches a predetermined level.

A bistable electro-optic display having at least one pixel is driven using a waveform V(t) such that:J=∫0T⁢V⁡(t)⁢M⁡(T-t)⁢ⅆt(where T is the length of the waveform, the integral is over the duration of the waveform, V(t) is the waveform voltage as a function of time t, and M(t) is a memory function that characterizes the reduction in efficacy of the remnant voltage to induce dwell-time-dependence arising from a short pulse at time zero) is less than about 1 volt sec.

An aircraft phased array antenna system has transmit and receive antenna structures externally mounted on the aircraft fuselage. Each antenna comprises a plurality of phased array elements and antenna power and support equipment. Aerodynamically shaping antenna structure to enclose an antenna element grid provides additional antenna structure volume, which is efficiently utilized by locating antenna support equipment within the antenna structure. To control signal attenuation a receive antenna internal converter converts receive frequency signals to L-band frequency signals for aircraft use, and a similar transmit antenna converter converts L-band frequency signals to transmit frequency signals, thus unconstraining antenna to internal aircraft equipment spacing. To reduce power loss and cabling weight, antenna operating power is first generated in the 28 to 270 volts DC range within the aircraft, and locally converted in each antenna to the 3 to 6 volt DC power to operate each antenna's phased array elements.

To reduce viewing angle dependence of γ characteristics in a normally black liquid crystal display.Each pixel 10 has a first sub-pixel 10a and a second sub-pixel 10b which can apply mutually different voltages to their respective liquid crystal layers. Relationships ΔV12 (gk)>0 volts and ΔV12 (gk)≧ΔV12 (gk+1) are satisfied at least in a range 0 <gk≦n−1 if it is assumed that ΔV12=V1−V2, where ΔV12 is the difference between root-mean-square voltage V1 applied to the liquid crystal layer of the first sub-pixel 10a and root-mean-square voltage V2 applied to the liquid crystal layer of the second sub-pixel 10b.

A passive element memory array preferably biases selected X-lines to an externally received VPP voltage and selected Y-lines to ground. Unselected Y-lines are preferably biased to VPP minus a first offset voltage, and unselected X-lines biased to a second offset voltage (relative to ground). The first and second offset voltages preferably are identical and have a value of about 0.5 to 2 volts. The VPP voltage depends upon the memory cell technology used, and preferably falls within the range of 5 to 20 volts. The area otherwise required for an on-chip VPP generator and saves the power that would be consumed by such a generator. In addition, the operating temperature of the integrated circuit during the programming operation decreases, which further decreases power dissipation. When discharging the memory array, the capacitance between layers is preferably discharged first, then the layers are discharged to ground.

High voltage direct current systems to connect direct current energy sources to an alternating current system. In one aspect, a system includes a plurality of direct current modules having variable direct current inputs; an inverter; and a direct current bus to connect the direct current modules to the inverter, where the bus is configured to operate at a nominal voltage higher than 100 volts and to operate within 10 percent of the nominal operating voltage.

A battery controller for charging and discharging a plurality of batteries is disclosed. The battery controller has a plurality of direct current to direct current (DC to DC) converters connected to each other in series. Each battery of a plurality of batteries is electrically connectable to a respective DC to DC converter. A co-ordinator connected to each of the plurality of DC to DC converters controls charging and discharging of the battery electrically connected to the respective converter. The co-ordinator can also control charging and discharging of any one of the batteries to ensure that the battery retains sufficient electrical capacity, and, to increase the longevity of the respective batteries. Because each battery is electrically connected to a respective DC to DC converter, the energy from one battery can be used to charge another battery in order to monitor battery characteristics including energy capacity of each battery. Each of the DC to DC converters is selected to operate preferably below 30 volts while the total voltage of the entire battery system can be much more than 30 volts depending on the number of DC to DC converters placed in series.

An implantable medical device, such as an implantable pulse generator (IPG) used with a spinal cord stimulation (SCS) system, includes a rechargeable lithium-ion battery having an anode electrode with a substrate made substantially from titanium. Such battery construction allows the rechargeable battery to be discharged down to zero volts without damage to the battery. The implantable medical device includes battery charging and protection circuitry that controls the charging of the battery so as to assure its reliable and safe operation. A multi-rate charge algorithm is employed that minimizes charging time while ensuring the battery cell is safely charged. Fast charging occurs at safer lower battery voltages (e.g., battery voltage above about 2.5 V), and slower charging occurs when the battery nears full charge higher battery voltages (e.g., above about 4.0 V). When potentially less-than-safe very low voltages are encountered (e.g., less than 2.5 V), then very slow (trickle) charging occurs to bring the battery voltage back up to the safer voltage levels where more rapid charging can safely occur. The battery charging and protection circuitry also continuously monitors the battery voltage and current. If the battery operates outside of a predetermined range of voltage or current, the battery protection circuitry disconnects the battery from the particular fault, i.e. charging circuitry or load circuits.

A work light for work or task areas which uses light-emitting diodes (LEDs) as the source of light. LED clusters are mounted on a circuit board which is located in a housing. The LED work lights may be powered by conventional 120 or 240-volt electrical outlets, a DC generator, a battery, a battery pack, or a car adapter.