26361 results about "Comparator" patented technology

An exemplary LCD includes a frame memory configured for receiving a plurality of first gradations of current frame and outputting a plurality of second gradations of preceding frame pre-stored therein; a comparator configured for receiving, comparing the first gradations with the second gradation to generate a comparison result; a luminance detector configured for detecting a luminance degree of each of pixel according to the gradations of current frame; a calculator configured for calculating a complication degree of a picture to be displayed in current frame; and a gradation processor configured for receiving the first gradations of current frame to be displayed on the LCD panel, generating a plurality of pairs of compensating gradations according to the gradation of each pixel, and selecting one pair of the compensating gradations to be outputted to the LCD panel according to a received comparison result, a received luminance degree, and a received complication degree.

The invention provides an organic light emitting diode active driving system with current feedback, thereby a driving current for organic light emitting diode is not affected by variation of characteristic parameters of thin film transistor under an active driving mode. The active driving system in accordance with the invention includes a transistor and a current comparator for driving an organic light emitting diode. The transistor has two current carrying electrodes respectively connected to a cathode of the organic light emitting diode and ground, and a gate controlled by a data signal. The current comparator has two input terminals respectively receive a reference current with predetermined value and a driving current flowing through the organic light emitting diode. The current comparator compares the reference current and the driving current, and then outputs a voltage to the gate of the transistor in response to the comparison result so as to make the value of the driving current equal to that of the reference current. Therefore, the active driving system for organic light emitting diode array or flat panel display in accordance with the invention can achieve a desirable light emission uniformity.

Customer premises telephone equipment and methods are provided for identifying a calling party's telephone number, household name, and city and/or state location, to a called party. The equipment and method includes one or more directories containing city and state location information corresponding to a complete listing of all area codes an local exchanges throughout a selected calling region or country. A receiver receives an incoming telephone number of an incoming telephone call and a comparator compares the received incoming telephone number with the directory or directories containing the city and state location information to identify a city and state location associated with the incoming telephone number. The equipment includes a display for displaying the incoming telephone call number, the household name, and/or the city and state location associated with the incoming call.

A capacitive sensor includes a switching capacitor circuit, a comparator, and a charge dissipation circuit. The switching capacitor circuit reciprocally couples a sensing capacitor in series with a modulation capacitor during a first switching phase and discharges the sensing capacitor during a second switching phase. The comparator is coupled to compare a voltage potential on the modulation capacitor to a reference and to generate a modulation signal in response. The charge dissipation circuit is coupled to the modulation capacitor to selectively discharge the modulation capacitor in response to the modulation signal.

A novel integrated rectifier and boost converter circuit architecture is disclosed. The rectifier architecture includes a plurality of identical half-bridge rectifiers connected to receiving antennas to convert wireless AC power into DC power. The integrated rectifier may be coupled in series with a charging inductor in a boost converter. The inductor may discharge upon operation of two micro-controller-driven switching transistors using predetermined threshold and timing scheme to turn on/off. The rectifier architecture may provide high power densities, improve efficiency at larger load currents, and may be enabled in an integrated circuit with eight RF signal inputs, eight half-bridge rectifiers, and eight DC outputs ganged together as single feed into the boost converter. The rectifier circuit topology may include a comparator driven by the boost controller with a proprietary algorithm which suits control for a maximum power point tracking functionality, and an external micro-controller for additional control of the boost converter.

A PFM buck-or-boost converter is provided. The converter includes, inter alia, a hysteretic comparator, current sense circuitry, a logic circuit, drivers, current sense circuitry, a first buck switch, and a first boost switch. The current sense circuitry asserts signal Z if the current through the boost switch (from the load to the inductor) is greater than zero, and unasserts Z otherwise. Additionally, the current sense circuitry asserts signal I if the current through the buck switch is greater than a fixed current limit value, and unasserts I otherwise. The logic circuit employs the hysteretic comparator output, signal Z, and signal I to control the switches, and to determine whether to operate in buck regulation mode or boost regulation mode.

An LDO voltage regulator includes an error amplifier having a first input coupled to a first reference voltage, a second input receiving a feedback signal, and an output producing a first control signal. An output transistor has a gate, a drain coupled to an unregulated input voltage, and a source coupled to produce a regulated output voltage on an output conductor. A feedback circuit is coupled between the output conductor and a second reference voltage. An overvoltage comparator has a first input coupled to receive the first reference voltage and a second input coupled to respond to the feedback signal to produce a discharge control signal indicating occurrence of an output overvoltage of at least a predetermined magnitude to control a discharge transistor coupled between the output conductor and the second reference voltage. An output current sensing circuit produces a control current representative of the drain current of the output transistor. An offset capacitor is coupled between the output of the error amplifier and the gate of the output transistor, and a servo amplifier has a first input coupled to receive a third reference voltage, a second input coupled to the output of the error amplifier, and an output coupled to the gate of the output transistor to produce a second control signal thereon. A current sensor circuit, a current capacitor, and an AND circuit operate to allow the discharge transistor to be turned on only if the output current is below a certain level.

A control circuit for a switching DC/DC Converter comprising: an input for an indicator signal indicative of an output current level from said converter; a peak detector for detecting and storing a maximum value of said indicator signal; a comparator element for comparing an instantaneous value of said indicator signal with said stored maximum value, and for generating a switching signal when said instantaneous value becomes less than a predetermined fraction of said stored value; reinitializer means for reinitializing said peak detector in response to said switching signal; and means for generating a control signal that switches between a state in which it increases over time and a state in which it decreases over time in response to said switching signal. A control module for photovoltaic generator, the module including such a control circuit, and a photovoltaic generator system comprising a plurality of such modules, each controlling a respective photovoltaic generator.

Electronic equipment, such as a mobile phone, PDA or other device, is operative to turn on and to turn off keylock function or another function or to alter a characteristic of such function in response to shaking or other movement of the electronic equipment, e.g., when the mobile equipment is shaken at a given frequency and amplitude, according to a given code, in a given direction, e.g., twisting/twirling and/or in an arcuate path or linear path. The electronic equipment includes a motion transducer providing motion signals representing motion and a comparator that compares motion signals to determine whether they match predetermined or programmed motion signals.

A method of turning on or off or altering a function or a characteristic of a function of electronic equipment includes detecting occurrence of motion and in response thereto carrying out the turning on, turning off and/or altering if that motion matches a predetermined or programmed motion. The method may include shaking the electronic equipment in a hand, moving the electronic equipment linearly, in an arc, in a rotation, etc. The electronic equipment may be programmed with the predetermined motion.

A system comprises a rotary apparatus, a control law and a processor. The rotary apparatus comprises a rotor and a housing forming a gas path therebetween, and the control law controls flow along the gas path. The processor comprises an output module, a plurality of temperature modules, a thermodynamic module, a comparator and an estimator. The output module generates an output signal as a function of a plurality of rotor and housing temperatures defined along the gas path, and the temperature modules determine time derivatives of the rotor and housing temperatures. The thermodynamic module models boundary conditions for the gas path, and the comparator determines errors in the boundary conditions. The estimator estimates the rotor and housing temperatures based on the time derivatives, such that the errors are minimized and the flow is controlled.

A CMOS image sensor includes column-parallel ADCs. Each of the ADCs includes a comparator and an up/down counter. With this configuration, digital values of pixels in a plurality of rows can be added without using additional circuits, such as an adder and a line memory device, and the frame rate can be increased while maintaining constant sensitivity.