46results about How to "Increase switching speed" patented technology

The invention discloses a high-reliability low-cost multichannel RS-422 communication circuit which comprises a signal receiving unit and a signal transmitting unit. The signal receiving unit comprises a photoelectric coupler U1, current limiting resistors, filter capacitors and level clamp diodes, and the signal transmitting unit comprises a transmitting chip U2 and current limiting resistors; RS-422 communication transmitted signals can be transmitted to the transmitting chip U2 from an MCU (microprogrammed logic control unit) in TTL (transistor-transistor logic) level forms and can be converted into differential signals, then the differential signals can be outputted via the second current limiting resistor, currents of RS-422 communication received signals are limited by the first current limiting resistor, voltages of the RS-422 communication received signals are limited by the level clamp diodes, the RS-422 communication received signals are filtered by the filter capacitors andthen are transmitted into the photoelectric coupler U1, light emitting diodes of the photoelectric coupler can be turned on and off under the control, accordingly, the differential signals and TTL level can be converted, and signals can be isolated. According to the scheme, the high-reliability low-cost multichannel RS-422 communication circuit has the advantages that the high-reliability low-costmultichannel RS-422 communication circuit can be applied to RS-422 communication mode circuits on missiles, is high in switching rate and reliability and low in cost and is small and anti-interference, and the like.

The invention discloses a high-speed LED optical communication resonant quasi-switching modulator. The power supply unit is a voltage-limiting constant-current control unit, and the control unit is used to generate and output control signals to realize timing control; the power supply unit, inductance, resistance and current The source I1 is connected in series in sequence to form a loop; the anode of the LED is connected to the positive pole of the power supply unit, and the cathode is connected to the positive pole of the current source I2 through the switch K101; the cathode of the LED is connected to the positive pole of the current source I1; when the control unit sends a control signal to make the switch K101 turn on, the limit The voltage and constant current control unit supplies positive power to the LED to turn on the LED quickly; at the same time, the inductor stores energy; when the control unit sends a control signal and the switch K101 is turned off, the constant current drops, and the inductor generates a negative voltage. Reverse power supply to the LED during the falling time, so that the LED light intensity drops rapidly. The invention has fast switch and good optical communication effect.

The invention discloses a reactive compensation device and method for partially regulating voltages and capacitance of a three-phase four-wire power grid. The reactive compensation device comprises a U-phase voltage and capacitance regulating reactive compensation unit, a V-phase voltage and capacitance regulating reactive compensation unit, a W-phase voltage and capacitance regulating reactive compensation unit and a control unit. Each phase of voltage and capacitance regulating reactive compensation unit is mainly composed of a current detection element, a voltage detection element, a full-voltage compensation capacitor bank, an auto-transformer and a voltage-regulating capacitor bank. The control mode of independent reactive compensation in each phase is used in the three-phase four-wire power grid, total capacitance in each phase is uniform, the capacitance in each phase is evenly divided into n sets, wherein one set of the capacitance is subjected to voltage and capacitance regulation through the auto-transformer which totally has m levels of output voltages, each phase has n*m grades of compensation, and multi-level fine compensation for the power grid is achieved.

The invention provides a semiconductor capable of improving the current rebounding phenomenon of a reverse-conducting double-insulated-gate bipolar transistor, improving the turn-off speed and improving voltage resistance. The semiconductor is structurally characterized in that a buried oxide is arranged on a P-type substrate and provided with a drift region, the drift region comprises a first N-type drift region, a first P-type drift region, a second N-type drift region and a second P-type drift region, the first N-type drift region and the first P-type drift region are arranged in an opposite-angle mode, and the second N-type drift region and the second P-type drift region are arranged in an opposite-angle mode; a P-type region is arranged in the first N-type drift region and the second P-type drift region, an N-type emitter region, a P-type collector region and cathode metal connecting the N-type emitter region with the P-type collector region are arranged in the P-type region, and a cathode gate oxide and a cathode polycrystalline silicon layer are arranged on the upper surface of the P-type region; an N-type region is arranged in the first P-type drift region and the second N-type drift region, an N-type collector region, a P-type emitter region and anode metal connecting the N-type collector region with the P-type emitter region are arranged in the N-type region, and an anode gate oxide and an anode polycrystalline silicon layer are arranged on the upper surface of the N-type region.

The invention discloses a semiconductor device having a buffer layer and a manufacturing method thereof. The semiconductor device comprises a front surface structure arranged on the front surface of the semiconductor device and a back surface structure arranged on the back surface of the semiconductor device. The back surface structure comprises a P<+> collector region and the N-type buffer layer arranged on the P<+> collector region. The P<+> collector region and the N-type buffer layer each adopt a thin film structure which is formed directly on the back surface of the semiconductor device by utilizing the low-temperature PECVD technology. The P<+> collector region and the N-type buffer layer further adopt the deposited thin film structure formed through the low temperature PECVD technology. The thin film is one or more of amorphous silicon, microcrystalline silicon, carbon-doped amorphous silicon or silicon germanium. According to the semiconductor device having the buffer layer and the manufacturing method thereof, cost of the semiconductor device and thermal budget of the silicon wafer back surface technology can be reduced effectively on the basis of not using an ion implantation device and an annealing process, and injection and extraction rate of carriers on the back surface of a silicon wafer can be adjusted according to the difference of the types of thin-film materials.

The present invention aims at the problem that the thickness of a single layer of metal of a metal composite material cannot be measured and the overall thickness of the metal composite material cannot be measured in the prior art, and provides a metal composite material ultrasonic thickness measurement capable of measuring the thickness of each layer of the metal composite material Instrument, which includes a voltage adjustable power supply, an ultrasonic transmitting module, an ultrasonic receiving module, a data acquisition module, and a data processing system. The power supply provides power for the ultrasonic transmitting module, the ultrasonic receiving module, the data acquisition module, and the data processing system. A kind of ultrasonic thickness gauge for metal composite materials, the accuracy and reliability can be guaranteed, and the thickness can be accurately measured even in some cases of poor coupling.