7results about How to "Small duty cycle" patented technology

The invention relates to an anti-ant large-core-number fiber ribbon cable comprising a cable core and an outer sheath. The cable core includes loose tubes; and fiber ribbons are sleeved inside the loose tubes. The outer sheath is an outer nylon sheath; and a non-metallic reinforcement layer is arranged between the outer sheath and the cable core. According to the anti-ant large-core-number fiber ribbon cable provided by the invention, with the outer nylon sheath, ants can not bite the sheath, so that the damages on the optical cable by ant biting in a pipe at an area with a serious anti problem are prevented, the normal state of the cable is ensured, and the application region of the cable is extended. The cable based on a simple and reasonable structure has advantages of small cable diameter, high fiber density, large fiber capacity, and low duty ratio and can be laid in a pipe conveniently; and the bending performance is good. During branched connection, 4 to 24 fibers can be melted once, so that the construction time is saved and the manpower cost is lowered, and the construction efficiency is improved. On the basis of the full drying type dielectric structure, branched connection is realized conveniently and usage becomes convenient.

The application discloses a bipolar high-gain Cuk DC-DC converter for a direct-current microgrid, and relates to the field of voltage converters.The bipolar high-gain Cuk DC-DC converter comprises a coupled input unit, a bipolar voltage boosting unit and an output unit which are adaptively connected.The coupled input unit comprises a switching tube S and a coupled inductor.The same name end of the primary winding L1 of the coupled inductor is connected with the first electrode of the switching tube S, the third electrode of the switching tube S forms the positive input end of the coupled input unit, and the non-same name end of the primary winding L1 of the coupled inductor forms the negative input end of the coupled input unit.The first electrode of the switching tube S is connected with the neutral point of the output unit through the bipolar voltage boosting unit, the negative input end of the coupled input unit is connected with the negative output end of the output unit through the bipolar voltage boosting unit, and the output voltage amplitude of the positive output end and the negative output end of the output unit relative to the neutral point is equal.The converter has the advantages of high gain, self-voltage equalization, no need of an additional clamping circuit, high efficiency and strong reliability.

The embodiment of the invention discloses an audio amplifier chip controlled through digital input and an audio amplifier. The audio amplifier chip comprises an input port, a DAC, a positive voltage power supply, a gate drive unit, a half-bridge circuit, a negative voltage control mechanism algorithm and a negative voltage generation circuit, and the half-bridge circuit is formed by connecting two switching tubes in series; wherein the input port is used for receiving a digital input audio signal, and the input port is respectively connected with the voltage generation circuit and the gate driving unit through the DAC; the negative voltage generation circuit is used for generating negative voltage according to a negative voltage control mechanism algorithm and a digital input audio signal; the gate driving unit is used for generating a PWM signal according to a digital input audio signal; the duty ratio of the pulse width modulation signal is determined according to the voltage output by the positive voltage power supply, the negative voltage and the output signal of the audio amplifier chip; and applying a pulse width modulation signal with a duty ratio to the grid electrode of the switching tube. The embodiment of the invention can reduce the device cost and improve the performance of the audio amplifier.

The invention discloses a phase frequency detector based on capture acceleration and noise suppression dual-mode adaptive switching, and the phase frequency detector employs a duty ratio shaping module to shape a reference signal and a feedback signal, reduces the duty ratio, expands the working range of a capture acceleration mode, and facilitates the reduction of the locking time of a loop. A mode controller is used for detecting the phase difference of a reference shaping signal and a feedback shaping signal, judging a locking state and controlling a reset path to be switched between a capture acceleration mode and a noise suppression mode, a high phase discrimination blind area introduced by the noise suppression mode is eliminated, and the phase discrimination range of the phase frequency detector is expanded. Reset paths adopted by the invention are a capture acceleration path and a noise suppression path, the capture acceleration path adopts an input delay sampling technology, inherent delay of a reset signal during generation and transmission is counteracted, a phase discrimination range is effectively expanded, and a phase discrimination blind area of the phase frequency detector is reduced; the noise suppression path optimizes the time sequence of reset signal generation and expands the loop charging and discharging time.

The invention relates to the field of power electronics, and particularly discloses an input-parallel output-series dual-active bridge switching tube open-circuit fault-tolerant control method, which comprises the following steps: fault detection: identifying the position of an open-circuit fault switching tube; fault-tolerant control is carried out, specifically, current bias is corrected by adopting strategies of reducing the duty ratio of a secondary side and increasing D3 or blocking a switching tube of the same bridge arm and increasing D1 for a primary side fault or a secondary side fault; adaptive voltage-sharing control is carried out, voltage reference values are dynamically generated in three stages of starting, stabilizing and tracking based on operation time and voltage states, control modes and parameters are switched in the tracking stage according to fault and imbalance conditions, and voltage balance among modules under all working conditions is realized; and carrying out change rate limitation and hard amplitude limiting on the voltage reference value. According to the method, current bias caused by faults can be effectively eliminated, current stress is reduced, and voltage balance and stability of the multi-module DAB system during switch tube open-circuit fault decline operation are ensured.

This application discloses a duty cycle monitoring circuit and a semiconductor device using the same. The duty cycle monitoring circuit includes a duty cycle reduction circuit, a duty cycle detection circuit, and a latching circuit. The duty cycle reduction circuit reduces the duty cycle of a first clock signal and a second clock signal to generate a first input signal and a second input signal. The duty cycle detection circuit detects the duty cycle of the first input signal and the second input signal to generate a first output signal and a second output signal. The latching circuit generates a duty cycle detection signal based on the first output signal and the second output signal.

This invention belongs to the field of material conveying technology, specifically relating to a bulk material conveying device and its usage method. By collecting multi-point pressure response values ​​from key sections of the conveying pipeline, a spatial multi-point pressure difference correlation model is constructed. Based on the positive deviation of the first pressure difference, the negative deviation of the second pressure difference, the inverse correlation of dual change rates, and a constant feeding rate, the system accurately identifies the precursory state of blockage. After identification, a tiered unblocking process is implemented: the first stage maintains a constant main air source pressure and adaptively adjusts the pulse pressure, frequency, and feeding rate; if the first stage is ineffective or the pressure difference continues to worsen, the second stage is initiated, increasing the main air source pressure and pulse frequency. After unblocking, an asymmetric step sequence is used to gradually restore operating parameters, continuously monitoring the pressure difference change rate during the restoration process to avoid secondary blockage. This invention achieves accurate identification of precursory blockages, dynamic adaptation of tiered unblocking, and a stable and controllable restoration process, significantly improving the operational reliability of the pneumatic conveying system.