65results about How to "The output voltage is accurate" patented technology

This transformer test control device permits testing of an electrical transformer as installed on a power pole without connecting any high voltage of the power distribution line to the transformer, thereby significantly enhancing the safety of the lineman during the testing procedure. A test control device for controlling the testing of an electrical transformer combines a visual indicator acting as both a power-on indicator and a fuse tester, a voltmeter, a voltage adjustment control, an operator control switch and a fuse as well as terminals for connecting both to an alternating current electrical supply and to the terminals of the primary coil of a transformer to be tested. Additionally, the test control device includes terminals for connecting the device and a secondary circuit to selected output terminals of the secondary coil of the transformer and additional terminals for receiving and retaining the contact portions of voltmeter test probes. The test control device simplifies the transformer testing and aids the lineman in testing while maintaining high standards for safety practices and, especially, during adverse weather conditions. This device may be embodied to include a dedicated second voltmeter. The test control device may be powered by either normal 120 volt line voltage or the output of a power inverter connected to the electrical system of a truck or other motor vehicle in those areas without readily available 120 volt AC power.

The invention relates to a capacitor-less low dropout regulator, which comprises a first-stage amplifier, a second-stage buffer, a voltage division circuit and an output transistor, wherein an impedance device is introduced between an output end of a common drain amplification circuit of the second-stage buffer and the ground, the impedance device is an active resistor device or a passive resistor device which is used for increasing the output resistance of the second-stage buffer, effectively controlling the damping coefficient of the capacitor-less low dropout regulator and reducing the influence of complex poles on dominant poles. Frequency compensation of the capacitor-less low dropout regulator is realized, and under the condition that a capacitor device does not need to be increasedadditionally, low-dropout output voltage is ensured to be precise and stable and have low noise, and the capacitor-less low dropout regulator can be used in a circuit capable of realizing monolithic integration and driving larger capacitive load.

A constant-voltage power supply circuit unit that is fed from a vehicle-borne battery via a power switch and generates a predetermined constant-voltage output Vcc includes a power transistor and an output voltage regulating circuit unit. The output voltage regulating circuit unit includes a reference voltage generating circuit, a comparison amplifying circuit, a resistance circuit network, a non-volatile second data memory that selectively continues plural open / close elements provided in the resistance circuit network, and a temperature detector. The quantity of variation of output voltage with respect to ambient temperature detected by the temperature detector is estimated, and a setting voltage is corrected to be approximate to a predetermined output voltage, or conversion correction of AD conversion data is performed on the basis of voltage variation characteristics of an analog sensor.

The constant voltage power source circuit which generates a predetermined constant voltage output Vcc by the use of power supplied from an in-vehicle battery via a power switch has a power transistor and an output voltage adjustment circuit. The output voltage adjustment circuit has a reference voltage generation circuit, a comparison amplification circuit, a resistance circuit network, and a nonvolatile second data memory selecting any of a plurality of on / off elements provided in the resistance circuit network and producing electric continuity of the selected on / off element. The constant voltage output Vcc is measured by an externally connected high accuracy voltmeter in the dispatch adjustment stage to be read out and stored via a serially connected external tool. Output voltage correction data are stored in the second data memory in such a manner as to set the external measurement voltage as a target voltage.

This invention relates to a switch control device connected to the primary side of a transformer to control the switch of the transformer to provide a DC power output including: a switch power switch with its output connecting to one end of the primary side of the transformer and the other connected with the input voltage, a current sensing device connected with the other output end of the switch to sense current signals by the switch action of the switch, a controller connected with the control end of the switch and the current sensing device and connected with the assist winding by a bleeder to get the voltage signals and discharge time from the winding and get current signals from the sensing device and output switch signals to the control end.

A voltage regulator calibration circuit including a voltage regulator and a calibration unit is provided. The voltage regulator regulates an output voltage according to a reference voltage and a feedback voltage. The feedback voltage is in direct proportion to the output voltage. The calibration unit is coupled to the voltage regulator. The calibration unit generates a control code through binary search according to the output voltage and a target voltage. The control code determines the proportion of the feedback voltage to the output voltage.

Provided is a semiconductor temperature sensor capable of enhancing accuracy of temperature detection. A constant current circuit (13) of a current supply circuit (10a) causes a constant current to flow. A current mirror circuit of the current supply circuit (10a) supplies a temperature detection current from an output terminal thereof according to the constant current of the constant current circuit (13). A temperature detecting circuit (10b) outputs an output voltage according to the temperature detection current and a temperature. A PMOS transistor (19) of a leak current absorbing circuit (10c) has the same size and conductivity type as those of a PMOS transistor (15), and absorbs a leak current included in the temperature detection current (drain current of the PMOS transistor (15)).

To provide a temperature sensor circuit capable of obtaining a highly precise output voltage as a desired output voltage. The temperature sensor circuit includes: at least a constant current source; and a base-to-emitter voltage multiplication circuit constructed by a bipolar transistor and resistors, in which a base current error compensation circuit is provided so as to eliminate an error of the base current of the bipolar transistor caused to flow through the resistor. Further, the temperature sensor circuit of the present invention has such a structure that a resistance value of the resistor that determines an output voltage may be controlled.

A circuit with adjustable phase delay and a feedback voltage includes a delay setting unit and a phase delay signal generator. The delay setting unit generates a delay time according to an external resistor. The phase delay signal generator includes a plurality of phase delay units. Each phase delay unit includes an edge trigger subunit and a signal generation subunit. The edge trigger subunit receives an input signal, and generates a positive edge trigger signal and a negative edge trigger signal according to a positive edge and a negative edge of the input signal, respectively. The signal generation subunit generates and outputs a phase delay signal according to the positive edge trigger signal, the negative edge trigger signal, and the delay time. The phase delay signal lags the input signal for the delay time.

Provided is a voltage regulator including a phase compensation circuit capable of obtaining an accurate output voltage. The phase compensation circuit includes: a first constant current circuit connected to a gate of an output transistor; a first transistor having a drain connected to the gate of the output transistor; and a second transistor having a drain connected to a gate of the first transistor, a second constant current circuit, and a resistor and having a gate connected to the resistor and any one terminal of a first capacitor, the first capacitor having the other terminal connected to an output terminal of the voltage regulator. This configuration prevents a current from flowing from an output terminal of the differential amplifier circuit to the drain of the first transistor, to thereby reduce an offset voltage to be generated in input transistors of the differential amplifier circuit, thus obtaining an accurate output voltage.

Disclosed is a three-level Boost converter neutral-point potential balance control method. The method is characterized by comprising the steps that 1, a voltage sensor VTincap1 is arranged on a three-level Boost converter output filter capacitor Cb1, detection data is capacitor voltage ucb1, a voltage sensor VTincap2 is arranged on the output filter capacitor Cb2, and the detection data is capacitor voltage ucb2; 2, a controller is connected to a three-level Boost converter, and the controller comprises an AD conditioning circuit, a DSP, an FPGA and a driving circuit; the two input ends of thecontroller are connected with the voltage sensor VTincap1 and the voltage sensor VTincap2 respectively, the sampling signal capacitor voltage ucb1 and the capacitor voltage ucb2 enter the controller,and output signals of the controller are drive pulse connected to two switching tubes Qb1 and Qb2; a deviation voltage gain feature coefficient sectional analytical expression is given, and the sectional fitting method based on maximum deviation voltage conditions is put forwards, so that different duty ratio section phase delay boundary conditions are determined, and therefore the deviation voltage is better and effectively regulated.

A capacitive load driving circuit has an input terminal, a front-edge delay circuit, a back-edge delay circuit, an amplifying circuit, and an output switch device driven by the amplifying circuit. The front-edge delay circuit delays a front edge of an input signal input via the input terminal, the back-edge delay circuit delays a back edge of the input signal, and the amplifying circuit amplifies a drive control signal obtained through the front-edge delay circuit and the back-edge delay circuit.

A reference voltage generating circuit generates a reference voltage Vref. An A / D converting circuit compares an analog input voltage Vin with the reference voltage Vref to convert the analog input voltage Vin to a digital output value Dout. A measured value storing circuit stores a measured value of the reference voltage Vref in advance and outputs the stored measured value. A user of an A / D converter corrects the digital output value Dout from the A / D converting circuit by use of the measured value of the reference voltage Vref outputted from the measured value storing circuit, thereby obtaining a digital value representing the analog input voltage Vin accurately irrespective of the accuracy of the reference voltage Vref.

An inverter unit includes a DC power source, an inverter circuit having two or more pairs of switching elements which are connected in parallel to the DC power source, so that a DC voltage of the DC power source is converted into a pulse train-like, pseudo-AC voltage output from the inverter circuit, and a PWM generator connected to the inverter circuit for adjusting the pseudo-AC voltage by pulse width modulation. Further, the inverter unit includes a voltmeter for detecting an actual, output voltage which is output from the inverter circuit, and a duty cycle controller for controlling an output duty cycle, so that the detected, actual, output voltage becomes a target output voltage. In this inverter unit, a desirable, output voltage may be obtained stably and accurately even if a voltage of a power source fluctuates.

The present invention relates to an electrical power adaptor with self-adjusting output voltage regulation which comprises a switching power supply circuit for converting an alternate current into a direct current, and a power supply return circuit connecting with the switching power supply circuit. The switching power supply circuit comprises an EMI filter circuit, a full-bridge rectifier circuit, a switching transformer, a secondary rectification filter circuit, a PWM control circuit and an optocoupler feedback control circuit. The power supply return circuit comprises an output line, output adaptor and an MCU main control circuit. The MCU main control circuit is connected with the switching power supply circuit. The output adaptor is disposed with a signal resistor. The MCU main control circuit controls the output voltage of the switching power supply circuit according to the signal resistor of the output adaptor. The electrical adaptor of the present invention provides a wider range of output voltages with higher precision. Furthermore, by connecting a signal resistor to an output adaptor and altering feedback resistance of a feedback network according to feedback signals of the signal resistor, the signal resistor is not required to meet a very high standard of precision. The design of the present invention is safer and more personalized.

The invention provides a temperature detecting apparatus, a switch capacitor apparatus and a voltage integrating circuit. The voltage integrating circuit includes an operating amplifier, a capacitor and a current source. The operating amplifier has a positive input end, a negative input end and an output end. The output end of the operating amplifier generates an output voltage, and the positive input end receives a reference voltage. The capacitor is coupled between the output end and the negative input end of the operating amplifier. The current source is coupled to the output end of the operating amplifier. The current source draws a replica current from the capacitor, and a current level of the replica current is determined according to a current level of a current flowing to the negative input end of the operating amplifier.

An analog buffer which can be used for the source driving circuit of the liquid crystal display device and is provided with a voltage compensating mechanism comprises a reference voltage generator, a plurality of capacitances, a plurality of switches and a plurality of transistors. Through the reference voltage provided by the reference voltage generator, each capacitance can store the gate source pole voltage of the corresponding conducting transistor and is used for executing the gate source voltage compensating operation. Each switch controls the conducting cutoff state according to the corresponding control signal and further controls the compensation operation of the gate source voltage. Therefore the analog buffer of the invention has the function of compensating the gate source voltage of the conducting transistor and is used for reducing the error of the output voltage according to the input voltage to the allowable mini offset. Besides, the invention can reduce the power loss of the analog buffer and provides more accurate output voltage, and facilitates that the circuit of the analog buffer works in the signal voltage procession with a higher speed.