Abstract: An organic light emitting display including pixels, a scan driver, a data driver, a control line driver, and a compensation unit. The pixels are positioned in an area defined by data lines, scan lines, and control lines, and each includes an organic light emitting diode. The scan driver drives the scan lines. The data driver drives the data lines. The control line driver drives the control lines. The compensation unit extracts threshold voltage information of a driving transistor included in each pixel during a sensing period. In the organic light emitting display, the compensation unit supplies a preset voltage to a gate electrode of the driving transistor so that a second current flows during the sensing period, and supplies a reference voltage to a drain electrode of the driving transistor during the period in which the second current flows.

Abstract: A voltage control operation unit receives, from a subtraction unit, a value obtained by subtracting a detection value of a voltage from a voltage command value, and performs a control operation for setting the voltage to be equal to the voltage command value. The voltage control operation unit outputs the calculated control amount as a current command value. A current control operation unit receives, from a subtraction unit, a value obtained by subtracting a detection value of a current from a current command value, and performs a control operation for setting the current to be equal to the current command value. A driving signal generation unit generates a signal for driving a boost converter based on a duty command value received from the current control operation unit.

Abstract: The present invention includes systems, methods and apparatus for continuously, independently and in some cases remotely monitoring the operation of a current interrupter used to test a cathodic protection system, or the cathodic protection system itself, for verification of proper operation. Embodiments of the invention include electronic devices that may be temporarily attached to a current interrupter that is being used to test a cathodic protection system, or directly to the cathodic protection system itself. Embodiments of the invention monitor the activity of an interrupter by sampling the output (voltage and time) to identify the cycle(s) of the interrupter. The invention provides truly independent verification since it does not need to know in advance the sequence or cycle times of the current interrupter being monitored. The information obtained by the invention is output so that it may be provided to a user, displayed, downloaded or stored for future reference.

Abstract: Embodiments of an active bandpass filter are described. Such a filter includes a transistor; a series-tuned inductive-capacitive (LC) network (STLCN) in a common source circuit associated with the transistor to produce a tuned degenerative filtering of at least one interfering signal; and a first, variable resistance associated with the STLCN to provide a first control of a resonance quality factor (Q) associated with the filter. Other embodiments may be described and claimed.

Abstract: Methods and systems to achieve linear and exponential control over a current to drive color LEDs have been achieved. Current digital-to-analog converters (IDAC) comprising each an exponential current digital-to analog converter and a linear IDAC, being cascaded to each other are used for a linear and an exponential control of a current driving a set of color LEDs, preferably RGB LEDs. The linear part of the IDAC, which is converting the mantissa of a floating-point number is used to control the color composition of the color LEDs. The exponential part of the IDAC, which is converting the exponent of the floating-point number is used to control the brightness of the color LEDs. While fading from one color to a next color a linear color change is required. The exponential part of the IDAC is used to dim the LEDs from bright to dark and vice versa. In order to get the visual perception of a linear dimming an exponential current change is required.

Abstract: A plurality of LEDs is driven in parallel, in at least two modes. In a first mode, the LEDs are driven with a first voltage. In subsequent modes, the LEDs are driven with successively higher voltages. The forward voltage drop for each LED is monitored, and the driver switches from the first mode to successive modes based on the largest of the LED forward voltage drops. The current through each LED is controlled by directing a reference current through a first digitally controlled variable resistance circuit, and directing the LED current through a second digitally controlled variable resistance circuit having substantially a known ratio to the first variable resistance circuit and connected in series with the LED. A digital count is altered based on a comparison of the first and second currents, and the first and second variable resistance circuits are simultaneously altered based on the digital count.

Abstract: The well voltage of a CMOS circuit having low-threshold-voltage MOSFETs is controlled when the power supply is turned on, during normal operation, and when the supply voltage is cut off. The CMOS circuit can thus operate stably with lower power consumption, because latching-up is reduced when the supply voltage is applied to the CMOS circuit or when the supply voltage is cut off, and subthreshold current is decreased during normal operation.

Abstract: A circuit for synchronous rectification including two power MOSFET transistor switches in which the bottom switch is a P channel MOSFET, rather than an N channel MOSFET. The circuit of the present invention uses a single channel driver, rather than a dual driver and eliminates the deadtime associated with conventional circuits, thus minimizing reverse recovery losses. In an alternative arrangement, the position of the output filter is switched so that the N channel MOSFET conducts during the freewheeling time and the P channel MOSFET (with a larger RDSON) conducts during the conductor charge cycle.

Abstract: A thyristor, controllable by logic signals independent of its cathode voltage, includes a thyristor, a PNP transistor between the gate and the anode of the thyristor, and an NPN transistor between the base of the PNP transistor and a terminal connected to ground through a resistor, the base of the NPN transistor receiving the logic signals.

Abstract: A built-in drive-power-source semiconductor device of low cost having a good switching characteristic and a decreased switching loss. In operation, a reference charge potential is applied to a charging IGBT by a first constant voltage diode thereby turning on the IGBT to charge a battery means. When the charge potential of the battery means reaches a prescribed level, a MOSFET is turned on by a second constant voltage diode, shortcircuiting the first constant voltage diode, causing the charging IGBT is turn off to eliminate overcharging of the batter means and maintain the potential of the battery means at a prescribed value.

Abstract: An energy conversion device includes a discharge tube which is operated in a pulsed abnormal glow discharge regime in a double ported circuit. A direct current source connected to an input port provides electrical energy to initiate emission pulses, and a current sink in the form of an electrical energy storage or utilization device connected to the output port captures at least a substantial proportion of energy released by collapse of the emission pulses.