294results about How to "Low output impedance" patented technology

A bio-electrode for detecting heart signals and the like comprises a dry electode surface having an elevated resistivity to reduce the effect of polarization noise. The electrode is combined with a circuit having an external discharge resistor across which an output signal is obtained wherein the discharge resistor has a value which reduces the time constant of polarization noise to less than one second.

System for pulse-width-modulated class D audio amplifiers. In one preferred embodiment an adder is described to generate a difference signal responsive to an input signal and a feedback signal, a pulse-width-modulator coupled to the adder to compare the difference signal to a reference signal and produce a pulse-width-modulated signal based on the comparing, a filter coupled to an output of the pulse-width-modulator, and a loop filter having a first input coupled to the output of the filter and a second input coupled to the input of the filter, the loop filter to generate a feedback signal by applying transfer functions to signals at its inputs. The loop transfer function of the amplifier is minimum aliasing error transfer function. The minimum aliasing error properties provide low distortion and taking the feedback from the output of the filter reduces high frequency output impedance.

The invention discloses a light active and passive combined lower-limb power-assisted exoskeleton robot. A back and a waist are arranged up and down; a waist bundling connecting piece on the waist is connected with a back supporting piece on the back; hip joint rotary shafts on hip joints are hinged to waist hip connecting pieces on the waist; a spring upper pressing plates on the hip joints are connected with a spring adjusting plate; the spring adjusting plate is positioned at the upper end of the back supporting piece and is connected with the back supporting piece; leading pulley seats are fixedly connected with a waist fixing plate on the waist; the upper ends of thighs are hinged to connecting plates on the hip joints through leg hip connecting shafts; steel wire fixed parts on the hip joints are fixedly mounted on outer walls of thighs; the lower ends of the thighs are hinged to the upper ends of knee joint supporting shells through knee joint connecting shafts; a motor encoder, a motor, a speed reducer, a coupler and a lead screw are sequentially arranged in a knee joint from top to bottom; the upper end of shanks are connected with the knee joint supporting shells; and the lower ends of the shanks are hinged to feet through foot joint shafts. The light active and passive combined lower-limb power-assisted exoskeleton robot is used for military loadbearing.

The invention discloses a single-ended active probe circuit of a digital oscilloscope, which combines high-speed signal completeness test requirements and combines an existing component based on a broadband testing principle for analyzing a single-ended active probe. Through an impedance conversion module, the requirements of the single-ended active probe in high input impedance, smallest input capacitance and small output impedance are realized; simultaneously, through an output circuit, the single-ended active probe circuit can be matched with the input impedance of 50 ohm of the oscilloscope.

The invention discloses a BCD device and a manufacturing method thereof, which belong to the technical field of semiconductor power devices. In the invention, semiconductor devices such as a high-voltage nLIGBT, three high-voltage nLDMOSs, a low-voltage NMOS, a low-voltage PMOS, a low-voltage NPN and the like are synchronously integrated on the same chip, wherein the high-voltage nLIGBT, the high-voltage nLDMOSs and the low-voltage NPN are directly arranged on a single-crystal p-type substrate; the low-voltage NMOS is arranged in a p-type well; and the low-voltage PMOS is arranged in an n-type epitaxial layer. As p-type reduced-field layers are respectively arranged between the n-type epitaxial layer and an n-type shift region well, the n-type epitaxial layer on a p-type buried layer supplies an extra surface conducting channel to high-voltage devices, the conducting channel is increased, the specific on resistance of the high-voltage devices is reduced, and the manufacturing cost of the chip is further reduced. The nLIGBT device and the nLDMOS devices of the invention further have the characteristics of high input impedance, low output impedance and the like, and a high-voltage power integrated circuit formed by the nLIGBT device and the nLDMOS devices can be used in a plurality of products, such as consumer electronics, display drivers and the like.

There is provided a sensor tag device capable of detecting event data by a sensor tag all the time even when no radio wave is received, saving power supply for a microprocessor, and enlarging the radio communication distance. The sensor tag device includes generation means 6 and 7 using one or more environmental changes, power supply voltage rise control means 8, and power supply synthesis means 9, and power is supplied to a microprocessor 12 and event data is stored in the microprocessor 12 when an event, i.e., an environmental change has occurred. A power receiving circuit having a transmission/reception antenna, a built-in power receiving circuit, and the microprocessor and capable of bi-directional communication by radio waves is combined with a stab resonance RF boost circuit and a ladder boost rectification circuit.

A drive circuit is provided that can drive a display panel with low power consumption, and an electro optical device including the drive circuit and its drive method are included. Switching signals RSEL, GSEL, and BSEL for demultiplexing are produced so as to control turning switching elements DSWR, DSWG, and DSWB for demultiplexing on and off, which separate data signal where R, G, and B are multiplexed and transmitted. An overlapped period, for periods of activating RSEL, GSEL, and BSEL is set between the timing of changing polarity of common voltage and the timing of assuring writing data signal to a pixel electrode. A drive circuit includes a reference voltage production circuit and a digital to analog conversion circuit and an output circuit, which outputs a programmed voltage (a reference voltage having the same phase as the common voltage) during the overlapped period. The first reference voltage production circuit includes plurality of operational amplifiers and the first and second voltage division circuits.

A solid-state imaging device that suppresses streaking includes an imaging region in which unit cells are aligned in matrix, an A/D converter for converting an analog signal generated in the imaging region to a digital signal, and a ramp buffer having an input terminal and an output terminal. Ramp voltage is input to the input terminal, and a reference signal having the ramp voltage is output from the output terminal toward the A/D converter. The A/D converter includes a comparator disposed in each column for comparing an analog signal with a reference signal, and a counter disposed corresponding to the comparator for counting a comparison period of the comparator. The ramp buffer includes a feedback circuit for simultaneously outputting the reference signal to the multiple comparators and controlling the amount of current flowing to the output terminal according to the ramp voltage of the reference signal output from the terminal.

A switching power amplifier of class D has a switching stage for generating a block wave signal by alternately switching the block wave signal between supply voltages. A filter (24, 25) generates a power output signal (22) corresponding to an input signal to be amplified, which is coupled to a linear input (19) that is free of hysteresis. A control circuit (27, 28, 29) provides feedback between the output power signal and the linear input for controlling both the gain in the operational frequency range and also the alternately switching of the switching stage. Hence, the amplifier oscillates controlled via the same feedback loop that also controls the operational behavior of the amplifier, resulting in low output impedance and low distortion.

In a current drive system for current-driving a display panel such as an organic EL panel, display crosstalk caused by a bias-voltage variation due to induction from the display panel is prevented. For this prevention, the current drive system includes: a plurality of drivers for current-driving a plurality of display element circuits in the display panel; and a bias circuit with a low output impedance for generating a bias voltage and supplying the bias voltage to each of the drivers through a bias line. The output impedance of the bias circuit is set sufficiently low so that a voltage variation caused on the bias line due to switching operation of each switch in the drivers converges within a period during which display data is written.

The present invention relates to an oscillator outputting two triangle waves having the same amplitude and whose phases are inverted; and a pulse width modulator using the oscillator. A capacitor 3 is charged or discharged by a charge pump circuit 2 controlled by a Schmitt circuit 1, and a voltage integrated by a two-output differential amplification circuit 6 is positively fed back to the input of the Schmitt circuit 1 to output two triangle waves having the same amplitude and whose phases are inverted. Since the output stage is composed of a differential amplification circuit, the circuit has low output impedance and is protected from wiring capacity and connected input capacity, and since integral operation is caused to be performed by the differential amplification circuit, the distortion in the waveform of the triangle waves can be prevented.

Electronic circuitry for high-power, high-frequency excitation of electromagnetic acoustic transducers (EMAT) without the use of a matching transformer is described. This circuit contains a least 4 switching devices such as power Mosfet transistors, arranged in an H-Bridge configuration that are designed to drive various EMATs over a wide range of frequencies. The switching devices can be connected in parallel with respect to the H-Bridge and switched in sequence for greater power output and variety of wave forms. This circuit configuration can provide a many excitation waveforms including, Churp, Hemming window tone burst, rectangular tone burst and Barker Code wave forms.

An improved electronic pulser circuit based on the H-bridge topology is designed for driving the sensor coils of an electromagnetic acoustic transducer (EMAT) to correct the disadvantages of conventional H-bridge pulsers and pulsers that require the use of an output transformer. A plurality of switching devices, primarily power Mosfets, are connected in parallel and augmented with support circuitry to provide improved performance in terms of increased power output, stability, reduced noise and complex output wave forms. This improved design provides for the application of modulated pulses such as multi-pulse, multi-frequency tone bursts of peak power outputs in excess of 20 thousand watts and frequencies in excess of 10 thousand Hertz.

The invention discloses a high-gain and high-isolation millimeter-wave double-balanced passive subharmonic mixer, which includes an active balun radio frequency input stage, a passive balun local oscillator input stage, a passive subharmonic mixing stage and Transimpedance output stage. The active balun amplifies the RF signal and the local oscillator differential signal generated by the passive balun for sub-harmonic mixing, and outputs an intermediate frequency signal through the transimpedance amplifier. In the mixing stage, the local oscillator signal is injected from the source of the transistor, and the radio frequency signal is injected from the gate to improve the conversion gain. The active balun is based on the cascode differential pair structure, adding cross-coupling tubes to improve the amplitude and phase consistency. The transimpedance amplifier uses the cross-coupling structure to enhance the gain, reduce the input and output impedance, improve the input current amplification capability and output drive capability, and further increase the conversion gain. The passive subharmonic mixer has the characteristics of high conversion gain and high port isolation, and is suitable for single-ended input and differential output mixing applications.

An RF driver circuit and an orthogonal antenna assembly/configuration, are disclosed as part of a method and system for generating high density plasma. The antenna assembly is an orthogonal antenna system that may be driven by any RF generator/circuitry with suitable impedance matching to present a low impedance. The disclosed RF driver circuit uses switching type amplifier elements and presents a low output impedance. The disclosed low-output impedance RF driver circuits eliminate the need for a matching circuit for interfacing with the inherent impedance variations associated with plasma. Also disclosed is the choice for capacitance or an inductance value to provide tuning for the RF plasma source.

The invention relates to a wireless parallel control method of a 400 Hz high-power inverted power supply, utilizing the integral value of active power P and reactive power Q to regulate the phase and the amplitude of the output voltage of each inverter in a plurality of inverted power supply parallel systems so as to equally distribute loads. A control system applying the control method at least comprises a 400 Hz inverted power supply module comprising an inverter (11), a pulse-width modulation (PWM) driving circuit (21) for driving the inverter (11), a series inductor (201) positioned at the output side of the inverter (11), an output phase detecting circuit (301) positioned on a public bus end, an output voltage detector (12) positioned on the output end of the inverter, and a load current detector (13) and a control unit (22) which are connected to the output end of the inverter in series. The output end of the inverter is connected with one parallel inductor in series and is connected to a public bus through a parallel switch; and the control unit realizes the control on the inverter through an operational control algorithm.

The invention discloses a high voltage generation device of a medical high-frequency high voltage generator, which comprises an oil tank, a high voltage main transformer, a small focus filament transformer, a big focus filament transformer, a high voltage rectifying plate connected with the output lead of the high voltage transformer, a high voltage dividing and sampling plate, an external wire holder, a high voltage cable socket and an oil hole cover. A main bracket is arranged in the inner cavity of the oil tank, an upper bracket is arranged at the upper part of the inner cavity; the high voltage main transformer is arranged at the middle part of the main bracket; the small focus filament transformer and the big focus filament transformer are arranged on the upper bracket; an oil hole and a breathing hole are arranged on the upper side of the oil tank; the high voltage rectifying plate is fixed at the lower part of the main bracket; the high voltage dividing and sampling plate is arranged at the outer side of the high voltage rectifying plate and is fixed at the lower part of the main bracket; both the external wire holder and the high voltage cable socket are arranged on the upper side of the oil tank; and the oil hole cover covers the oil hole. The DC high voltage outputted by the high voltage generation device is stable and has small ripple wave and high performance-price ratio.

The invention discloses a device and a method for underground long-distance transmission of Manchester code (Man code), and belongs to the technical field of communication and the technical field of oil exploration. The device for the underground long-distance transmission of the Man code comprises a Man code sending unit and a Man code receiving unit. The Man code sending unit comprises a Man code encoding module, a bipolar pulse generating module and a push-pull driver module. The Man code receiving unit comprises an inductance-capacitance (LC) parallel resonant module, a unipolar pulse generating module, a Man code decoding module and a communication module. The Man code sending unit is used to compile data into a unipolar pulse and then generate a bipolar pulse, and the improved push-pull driver module is used to drive the bipolar pulse to be sent to a cable transmission unit. Appropriate inductance is selected in the Man code receiving unit and connected in parallel between a signal line of the receiving end of the cable transmission unit and a ground wire, LC parallel resonance is generated on the highest frequency component of Man code pulses, then the Man code unipolar pulse is generated, and the Man code unipolar pulse is decoded and transmitted to a host computer. The device and the method for the underground long-distance transmission of the Man code are suitable for an underground high temperature severe environment, the severe attenuation distortion drifting problem of single-ended signals in long-distance transmission can be resolved, and the unipolar pulse can be decoded correctly.

An output buffer is disclosed and includes a differential output buffer input configured for coupling to a differential output of an input circuit. The output buffer further includes an inductive voltage divider circuit coupled to the differential output buffer input, and configured to weaken a loading at the differential output of the input circuit.

A pixel driver architecture for an active matrix OLED display, the pixel driver architecture comprising a voltage-programmed master pixel programming circuit, and a first plurality of current-programmed slave pixel driver circuits, each coupled to said master pixel programming circuit.