7results about How to "Avoid pressure drop" patented technology

The utility model relates to radio frequency power amplifier technical field, concretely relates to a radio frequency power amplifier power supply circuit with bidirectional current drive, including two -way negative voltage protection circuit, second circuit, third circuit, fourth circuit, fifth circuit and sixth circuit, two -way negative voltage protection circuit is used for monitoring main road grid negative voltage Vgs main and peak value grid negative voltage Vgs peak, and is turned off drain electrode power VDS when any road negative voltage loss, second circuit is used for 50V direct current voltage to 12V, third circuit is used for 12V direct current voltage to 5V, fourth circuit is used for direct current 5V conversion direct current 5V, fifth circuit is used for direct current 5V conversion direct current 5.8V, sixth circuit is used for direct current 5V to direct current 2.5V, and increases bidirectional current drive ability, and the power supply of main road grid negative voltage Vgs main. The problem that the existing DC / DC negative voltage chip negative voltage adjustment is complex, current carrying capacity is insufficient and lacks bidirectional current drive ability has been solved.

The application discloses a battery protection board, a battery system and a mobile device. The battery protection board comprises a power meter chip, a current sampling circuit and a first protection circuit. The first end and the second end of the power meter chip are connected with the positive electrode and the negative electrode of a battery pack respectively. The power meter chip is used for measuring the actual voltage of the battery pack. The current sampling circuit is used for collecting the charging current of the battery pack and feeding back to the power meter chip. The first protection circuit is used for protecting the battery pack according to the actual voltage and the charging current of the battery pack. The power meter chip is used for sending the actual voltage of the battery pack and the charging current of the battery pack to a mainboard system, so that the mainboard system charges the battery pack according to the actual voltage and the charging current of the battery pack. The actual voltage of the battery pack can be measured more accurately. Since the mainboard system controls the charging current according to the difference between the actual output voltage of the charging chip and the actual voltage of the battery pack, the charging efficiency is high when the charging current is large.

The application provides a synchronous rectification Vcc power supply method and a power supply circuit, and aims at solving the technical problem that the existing synchronous rectification Vcc power supply circuit using a diode to prevent current backflow will generate a diode voltage drop, and thus lead to a VCC port voltage drop and an under-voltage lock state. The synchronous rectification Vcc power supply method is as follows: a backflow prevention unit composed of a MOS tube P1 and a MOS tube P2 is arranged between a VD port and a VCC port, the conduction or turn-off of the power supply circuit is controlled according to the comparison results of a VCC port voltage Vcc and a starting voltage vth1 or an under-voltage protection threshold vth2, the comparison result of the VCC port voltage Vcc and a sampling voltage vdla, and the comparison result of the VCC port voltage Vcc and a VCC port reference voltage Vref; when the VD port voltage is less than the VCC port voltage, the gates of the MOS tube P1 and the MOS tube P2 are connected to Vcc to form an equivalent diode, so as to prevent the VCC port from being discharged reversely; and when the VD port voltage is greater than the VCC port voltage, the VCC port is charged through the equivalent diode, so as to avoid the appearance of a diode voltage drop.

The application provides an oxygenator, comprising a shell and a pre-module arranged in the shell. The pre-module comprises a plurality of pre-units arranged in layers, and each pre-unit comprises three membrane filament layers arranged in layers, and the three membrane filament layers are arranged at an angle of 120 degrees between each other. The three membrane filament layers comprise one first pre-membrane filament layer and two second pre-membrane filament layers, the first pre-membrane filament layer is one of an oxygenation membrane filament layer and a temperature control membrane filament layer, and the second pre-membrane filament layer is the other of the oxygenation membrane filament layer and the temperature control membrane filament layer. In all pre-units, the arrangement angle of the first pre-membrane filament layer is the same. The pre-module forms a uniform blood passage, improves the uniformity of blood distribution, avoids a large pressure drop of blood in the blood passage, thereby reduces thrombosis, and is beneficial to exerting the best oxygenation efficiency of the oxygenator.

The utility model discloses an all-wheel-drive control circuit of a multi-rotor unmanned aerial vehicle and the multi-rotor unmanned aerial vehicle, which are applied to the technical field of unmanned aerial vehicle devices and are used for solving the problems of poor stability and reliability of a control circuit of the multi-rotor unmanned aerial vehicle in the prior art. Specifically, the main control circuit board and the power distribution driving circuit board are physically separated and are connected through a first connector; a plurality of mutually independent motor driving channels are arranged on the power distribution driving circuit board; the main control circuit board generates a plurality of power supply channel control signals and sends the signals to the motor driving channel through the first connector; and each motor driving channel connects or disconnects the connection between the corresponding motor and the external power supply under the control of the power supply channel control signal. Through physical separation of the circuit board and independent on-off control of the motor driving channel, the stability and reliability of the control circuit are improved.

This invention discloses a thermometer fixture suitable for transient processes in cryogenic systems, comprising a front guide tube, a rear guide tube, and a temperature measuring block with a temperature sensor mounting interface. The first end of the front guide tube and the first end of the rear guide tube are respectively connected to process piping, and the second ends of the front guide tube and the rear guide tube are respectively connected to the temperature measuring block. A heat exchange channel is formed inside the temperature measuring block, which communicates with the internal channels of the front and rear guide tubes to form a through-flow fluid channel. The fluid being measured can flow through the heat exchange channel and exchange heat with the temperature measuring block. This invention employs a through-flow structural design, combined with a temperature measuring block made of high thermal conductivity material and an optimized flow channel structure, significantly reducing the thermal inertia and thermal resistance of the temperature measuring system and improving the transient thermal response speed. It is particularly suitable for temperature measurement in cryogenic transient conditions such as superconducting cryogenic systems and modular hydrogen liquefaction equipment in the 20–30 K temperature range.

The utility model discloses an energy-saving efficient jet tray which comprises a lower tray and an upper tray, a plurality of lower sieve holes are formed in the lower tray, a plurality of upper sieve holes opposite to the lower sieve holes are formed in the upper tray, and trumpet hoppers are fixed between the lower sieve holes and the corresponding upper sieve holes. The middle of the lower tower plate and the middle of the upper tower plate jointly penetrate through and are rotationally connected with a vertical shaft through a bearing, extrusion assemblies are fixed to the surfaces of the bottom end and the top end of the vertical shaft correspondingly, each extrusion assembly comprises an end plate and a sliding sleeve, and cleaning assemblies are fixed to the outer side walls of the two sliding sleeves correspondingly. According to the utility model, the lower tower plate, the upper tower plate and the mounting plate are arranged, and the horn hopper is fixedly connected between the lower sieve pores of the lower tower plate and the upper sieve pores of the upper tower plate, so that the sieve pores are gradually expanded from bottom to top, and airflow flows upwards to pass through the lower sieve pores with smaller pore diameters and then pass through the upper sieve pores, so that the gas phase pressure drop in the tower body can be reduced, and the gas-liquid contact efficiency is improved; therefore, the energy consumption of the sieve-plate tower is reduced.