461results about How to "Small duty cycle" patented technology

The invention relates to a shifting register, a grid electrode integrated driving circuit and a display device. The shifting register comprises an input module, a first resetting module, an output module, a first pulling-down control module and a second pulling-down control module, wherein the input module is used for controlling a potential of a first node to be a first potential; the output module is used for providing a clock signal at a clock signal end to a signal output end; the first resetting module is used for providing a reference signal of a reference signal end to the first node; a first node control signal end and a second node control signal end are used for alternatively inputting a node control signal, so that the first pulling-down control module and the second pulling-down control module work alternatively and a reference signal of the reference signal end is provided for the first node and the signal output end respectively; and the duty ratio of bias voltage of each pulling-down control module is reduced so that the working life of the shifting register is prolonged.

An ultra-large truss type floating marine platform is composed of floating drums dispersed on water surface, a working platform above water surface, and connecting rods. Its advantage is high stability.

The invention discloses an adaptive input power charger and a method for controlling an input current of a charger. An input voltage of the charger is compared with a first reference voltage through a comparison circuit to generate a comparison result; and when the comparison result represents that current of input power is limited, a current regulation circuit controls the duty ratio of a power switch tube according to the comparison result to limit the input current of the charger so as to remove a current-limiting state of the input power. In addition, when the comparison result represents that the current of the input power is not limited, the current regulation circuit can also increase the current reference value of a current control loop according to the comparison result to increase charging current so as to achieve the purpose of quick charging. The adaptive input power charger can be used for adaptively performing current-limiting protection according to different input voltages, so that the adaptability is good.

The invention discloses an LED lighting system. The LED lighting system comprises a microprocessor for outputting a first pulse width modulation signal, a second pulse width modulation signal and a third pulse width modulation signal, a first constant-current driving module for outputting a first current according to the duty ratio of the first pulse width modulation signal, a red LED lamp set for outputting corresponding luminance according to the first current, a second constant-current driving module outputting a second current according to the duty ratio of the second pulse width modulation signal, a green LED lamp set for outputting corresponding luminance according to the second current, a third constant-current driving module for outputting a third current according to the duty ratio of the third pulse width modulation signal, a blue LED lamp set for outputting corresponding luminance according to the third current and a power module. According to the LED lighting system, colors can be set, and meanwhile brightness and darkness adjustment and soft switching protection and overheat protection of LED lamps can be achieved.

The invention relates to a self-tuning PID energy-saving temperature control method. The method comprises the steps that a target temperature value, a control period, a sampling period and a thresholdtemperature difference are set first; load heating power is increased; the current regional temperature sampling value of a controlled object is acquired, and the sampling period is combined to calculate the temperature rise rate; a PSO-DE algorithm combining particle swarm optimization (PSO) and differential evolution (DE) is used to adjust and calculate PID control parameters; the duty cycle ofthe output pulse of a control period is adjusted according to the operation result; heating power output is adjusted, so that the sampled temperature sampling value is approximately equal to the actual temperature value of the controlled object; a temperature error caused by the heating inertia is reduced; heating power is accurately controlled; and the energy saving effect is obvious. A self-tuning PID energy-saving temperature control module comprises the self-tuning PID energy-saving temperature control method, can accurately control the heating power, and has an obvious energy-saving effect.

The invention discloses an LED backlight driving circuit, a driving method and a liquid crystal display device. The LED backlight driving circuit comprises an LED light bar and a driving module of the LED light bar; the driving module comprises a backlight driving chip used for adjusting output voltage of the driving module, the backlight driving chip comprises a first comparator used for correcting the output voltage of the driving module, and an output end of the LED light bar is coupled to an inverted input end of the first comparator; a non-inverted input end of the first comparator is coupled to a protection module; and the protection module comprises a detection unit used for detecting output current of the driving module. When a current value detected by the detection unit is higher than a preset first current value, the protection module outputs first reference voltage to the non-inverted input end of the first comparator; and when the current value detected by the detection unit is lower than the preset first current value, the protection module outputs second reference voltage lower than the first reference voltage to the non-inverted input end of the first comparator. The LED backlight driving circuit, the driving method and the liquid crystal display device have the advantage that the efficiency of the driving module is improved.

The invention discloses a production method for Al-alloy cylinder. A series of problems that surface finish of cylinder inner face machined by prior production method is not fit to technology and use demand of cylinder, internal combustion engine scuffs cylinder easily, the stability of cylinder is bad and life time is short, are solved. The primary scheme is that cavity of Al-alloy cylinder is machined mechanically; the cavity surface machined mechanically is treated with micro arc oxidation in alkaline solution by DC pulse power supply to form alumina ceramic layer; the layer is washed and dried; the layer is machined mechanically and washed thereafter.

A transducer comprises stationary scale, active scale, transducer coil, driving circuit and control circuit as metal reflecting conductor arranged uniformly as per certain wavelength period and certain ruled shape is erected on stationary scale, a numbers of transducer coils with specific distance and shape are set on active scale, coils are connected to pulse circuit through driver and output sampler of transducer coil is connected to single-chip computer which its output is connected to display through display circuit, to pulse circuit through controller and to external equipment through communication interface.

An engine starter capable of cranking a crankshaft finally in forward direction after driving in revere direction, wherein a motor is energized so as to be intermittently rotated in forward direction before the driving in reverse direction at least under specified conditions so that assured start can be performed at all times, whereby, as necessary, the crankshaft (piston) can be moved to an optimum position and, in addition, this control can be realized without using any special angle sensor.

The invention discloses a switching power circuit, which comprises a switching tube, a first resistive divider, a second resistive divider, an inductive component, a freewheel diode, a load unit, a load current detection unit, a comparator, a D latch, an analogue-to-digital converter, a digital-to-analogue converter, a pulse width modulation (PWM) operating mode gate driving voltage generation unit, a first amplifier, a PWM comparator, a pulse frequency modulation (PFM) control unit, a first either-or selector, a second either-or selector, a digital logic unit and a gate driving unit. When a PFM control mode is adopted, the voltage of the switching tube is regulated according to a load to reduce power consumption in a light load condition and improve energy transmission efficiency; and in addition, in the light load condition, the gate driving voltage and switching duty cycle of the switching tube are reduced, so that the power consumption is simultaneously reduced, and the shortcoming that output power is regulated only dependent on the duty cycle of the switching tube to narrow the variation range of the duty cycle and further retard the sudden change of the load and cause large output ripples during mode switching is overcome.

The invention relates to a wide input range switching power circuit comprising a transformer. A secondary coil of the transformer can be connected with various common output-rectifier filter circuits; a primary coil of the transformer comprises a first winding and a second winding which are different in turn number; the turn number of the first winding is greater than that of the second winding; the first winding is connected in series with a counterpressure-resistant diode; each winding is connected with a switching tube; the two switching tubes are controlled by a control circuit unit connected with a power supply; and a PWM signal is input in an input terminal of the control circuit unit; the switching-on and the switching-off of the two switching tubes are controlled by different input signals. Another winding is added in the wide input range switching power circuit, the two windings work in different voltage segments respectively within the whole input voltage range; when the input voltage is low, the winding with less turn number works, a transformation ratio N becomes larger, and the dutyfactor is reduced; and when the input voltage is high, the winding with more turn number begins to work, the dutyfactor D becomes larger, and the problem of undersize dutyfactor is solved. The wide input range switching power circuit has better performance under the wide input range.

The invention discloses a method for measuring working junction temperature and thermal resistance of an electronic component by utilizing a vacuum environment, which relates to the field of electronic component measurement, and comprises the following steps of: putting a measured component in a vacuum system, wherein the vacuum system is connected with external devices, and the external devices comprise an A/D acquisition board, a computer, a power supply and a heating power supply; placing a temperature-sensitive resistor A near the heat source source, which is the active area of the measured component; enabling a temperature-sensitive resistor B to contact with one surface of a heating sheet and the other surface of the heating sheet to contact with the bottom which is the heat dissipation endpoint of the measured component; acquiring the time t1 required for establishing the temperature gradient from the active area to the heat dissipation endpoint; and acquiring the time t2 acquired for establishing the temperature gradient from the heat dissipation endpoint to the active area; the power applied to the measured component is P, and the making time is t1+t2; when the temperature-sensitive resistors A and B tends to a steady state value, the temperature is the temperature of the measured component in normal work, and the working temperature rise and the thermal resistance of the measured component can be obtained. The method has no demand on the packaging forms semiconductor devices or function modules and belongs to a non-destructive test.

The invention relates to a multifunctional current impulse transmitter and a control method. The transmitter is formed according to the following method: the positive electrode of a two-gear direct current power supply is connected with a depressurization chopping constant-current circuit, a clamping circuit, a short-circuit and bridge arm direct connection protective circuit, a bipolar current impulse generator and a load through a switch K; and the negative electrode of the two-gear direct current power supply is connected with the load through the depressurization chopping constant-current circuit and the bipolar current impulse generator. According to the invention, the two-gear direct current power supply is adopted to coarsely regulate an output voltage; the depressurization chopping constant-current circuit is used so as to precisely regulate the output voltage, thereby reducing the variation range of the duty ratio of the depressurization chopping constant-current circuit and improving efficiency; the clamping circuit can perform bootstrap on a capacitor of a clamping voltage source to generate a high voltage in no need of improving the voltage of a direct current power supply or providing an auxiliary power supply; the linearity and the steepness of the failing edge of the current impulse are changed through regulating the voltage of the linear clamping voltage source; and the short-circuit and bridge arm direct connection protective circuit is matched with an impulse controller, so that the circuit has a self-repairing function after a failure is removed.

The invention provides an electromagnetic resonance control circuit, an electromagnetic heating device and a method for controlling a transistor. The electromagnetic resonance control circuit comprises a power module, a resonance circuit, the transistor and a controller, the resonance circuit is connected to the power module, the transistor is arranged between the resonance circuit and the ground, and used for executing the power-on or power-off operation according to pulse width modulation signals sent by the controller to control the work state of the resonance circuit, and the controller is connected to the power module and the control end of the transistor, and used for adjusting the duty ratio of the pulse width modulation signals sent to the transistor according to the change condition of voltages output to the resonance circuit by the power module to control the power-on time of the transistor. According to the technical scheme, the power-on time of the transistor can be controlled according to the voltages output to the resonance circuit, power output is increased in a low-voltage area, power output is reduced in a high-voltage area, the peak voltage and the peak current of the transistor are reduced under the condition of identical power, and therefore the transistor is effectively protected.

The invention relates to the technical field of LC-VCOs, in particular to a low phase noise LC-VCO. The current switching speed of a cross-coupling MOS pipe is improved, the current waveform duty ratio of the cross-coupling MOS pipe is reduced, and phase noise of the low phase noise LC-VCO due to the cross-coupling MOS pipe is further lowered. In addition, the number of traps of an NMOS pipe of a tail current source is reduced, and the phase noise of the low phase noise LC-VCO is further reduced. Energy provided by cross-coupling negative resistance is improved, the oscillation waveform amplitude of an oscillation circuit is improved, and the phase noise of the low phase noise LC-VCO is further reduced.

The invention relates to a six-degree-of-freedom series-connected robot with target positioning applied to inertial confinement fusion. By using a form of a series-connected mechanism for separating translation and rotation, and the six-degree-of-freedom series-connected robot with target positioning consists of a set of three-dimension translation work table and a set of three-dimension rotary robot. The translation and the rotation of each direction are both driven by a vacuum special motor actuator, each movement is relatively independent, and the precision movement of six freedom degrees can be finished in the space. By constructing a precise vacuum positioning mechanism with the six-degree-of-freedom in the space, the invention has the advantages of compact structure, small duty ratio angle, high motion resolution, easy control and precise positioning.

A fluid driven single-freedom flexible joint used for manipulator, robot, or artificial limb features that the fluid is used as its drive source, the stressed expansion of elastic corrugated shell is used as its kinetic force, the bent angle of the joint is associated with the fluid pressure in elastic corrugated shell, and the tensional spring, elastic belt or torsional spring are used for straightening it. It has high dynamic control precision.

The invention discloses a multiple working mode method for a touch screen. The invention comprises a normal working mode, and further includes a standby working mode. The normal working mode comprises a plurality of normal work cycles, and the standby working mode comprises a plurality of standby work cycles. The normal work cycles are as follows: a processor receives a processed touch recognition signal, if the touch is existed, and the processor calculates touch coordinates which are sent to a mainframe, thereby returning to a starting stage in the normal work cycles by the processor; the standby work cycles are as follows: the processor receives the processed touch recognition signal, is no touch is existed, and the processor controls the fixed delay, thereby returning to the starting stage in the standby work cycles. The invention provides a plurality of working modes, the normal working mode is entered when detecting touch medium, thereby working in the normal work cycle with a short time; the standby working mode is entered when being idle because no touch medium is detected, thereby working in the standby work cycle with a long time; therefore, the service life and reliability of the touch system are increased.

The invention discloses a back light source drive circuit directly driving a lamp strip circuit by using a primary half-bridge resonance circuit. The back light source drive circuit comprises a primary resonance circuit, a secondary lamp strip circuit and an optical isolating feedback circuit having an optical coupling feedback function, wherein the primary resonance circuit generates a driving pulse signal according to the received external voltage and a current signal fed back by the optical isolating feedback circuit, and provides needed work voltage for the secondary lamp strip circuit according to the driving pulse signal; and the optical isolating feedback circuit samples the loaded current in the secondary lamp strip circuit in real time, and feeds back the current signal to the primary resonance circuit. The back light source drive circuit directly lightens and controls the back light source by using the primary half-bridge resonance circuit; and optical coupling is used as the feedback control from the secondary level to the primary level. The drive circuit is simplified so as to eliminate a secondary side LED driving chip, and reduce device number of the whole system.

The present application provides a three-dimensional video system including a structured light module for emitting structured light. The structured light module includes a first light-emitting unit. The first light-emitting unit receives a first pulse signal and generates a first pulse signal according to the first pulse wherein a duty cycle of the first pulse signal is less than a specific value,a light emitting power of the first light-emitting unit is greater than a specific power, and the first light has a first wavelength; and a light-sensitive pixel array is used for receiving reflectedlight corresponding to the structured light.

The invention belongs to the field of electric welding and particularly relates to an arc striking pulse peak current control electric welding machine and a control method thereof. The electric welding machine applies a low-frequency low-duty-ratio pulse current during short circuit, and an arc striking pulse peak current of the low-frequency low-duty-ratio pulse current ranges from a 30A welding current to a triplex welding current. Therefore, the arc striking pulse peak current can be higher than the welding current during the low welding current, and arc striking is facilitated; and the arc striking pulse peak current can be lower than the welding current during the high welding current, a short-circuit limit output circuit is cut off after arc striking in welding is successful, the welding current slowly rises from the minimum current to the welding current, and the striking current can be reduced by the means.

The embodiment of the invention provides a shift register unit and a driving method thereof, a gate drive circuit and a display device, and relates to the technical field of display. Bias voltage affecting time of thin-film transistor components of a model can be greatly reduced, the change of the electrical properties of the thin-film transistors can be reduced and long-term stability of the whole panel under the condition of high reliability testing can be enhanced. The shift register unit comprises a first input unit, a second input unit, a first reset unit, a second reset unit, a first output unit, a second output unit, a first pull-up unit, a second pull-up unit, a first pull-down unit and a second pull-down unit. The shift register unit and the driving method thereof, the gate drive circuit and the display device are used for manufacturing of displayers.

An LCD device having a backlight generates a backlight brightness control signal in response to a duty rate signal corresponding to an average gray level or/and a color state of image data to be displayed on the LCD device and a brightness control voltage generated from the main body of the computer by user, and controls a brightness of the backlight automatically according to the backlight brightness control signal.