44results about How to "Control duty cycle" patented technology

A tunable, low power clock generator employs a voltage regulator, one or current generators and a variable resistor bank that, together, produce a control voltage for trimming a VCO. The control voltage is arranged to also compensate, at least, for the variables of temperature, supply voltage and fabrication processes as they affect the VCO output frequency. The current generator is well characterized over the variables discussed and the resistor bank is a flexible series / parallel array of resistors made from differing materials exhibiting different temperature coefficients. The resistor bank provides for various overlapping resistance values simultaneously with various overlapping temperature coefficients wherein the temperature coefficient profile of the clock generator over frequency and temperature is controlled.

The invention discloses a backlight module, a display device and a drive method of the display device, and belongs to the technical field of displaying. The technical problem that the color crack phenomenon exists in an existing FSC liquid crystal displayer is solved. The backlight module comprises a controller and a plurality of partition backlights. Each partition backlight comprises at least two light sources with different colors, wherein the two light sources are independently driven. The controller controls the turning-on time of the light sources with different colors in all partition backlights. The backlight module can be used for liquid crystal display televisions, liquid crystal displays, mobile phones, tablet personal computers and other display devices.

The invention discloses a temperature control system, which comprises a lower computer and an upper computer, wherein the lower computer consists of an automatic voltage regulation (AVR) single chip microcomputer, a temperature sensor, a light-emitting diode (LED) display, a temperature setting circuit and a temperature heating circuit; and the upper computer consists of a personal computer (PC) and interactive software. According to the system, temperature and time for keeping the temperature can be input to the upper computer according to a temperature curve required by a user, the lower computer controls the gradience of the temperature and the system can meet requirements of users on different temperatures at different moments, responds sensitively and has higher accuracy.

The invention provides a capacitor voltage balance control method of a cascade reactive power compensation device, belonging to the technical field of reactive power compensation control, and aiming at solving the problem that the existing method for balancing the capacitor voltage of a power unit is complex in process and unstable in control status. The method comprises the following steps of: firstly, acquiring the alternating current-side voltage u and the alternating current-side voltage i of each power unit in the cascade reactive power compensation device to obtain the instantaneous power polarity of each power unit; sampling the instantaneous capacitor voltage of a power unit by the frequency which is same as that of the carrier of the reactive power compensation device to obtain a voltage adjusting value of the power unit to be taken as a modification value of the carrier; confirming the modification value of the carrier and the overlapping mode of the carrier, and obtaining the adjusted carrier; and comparing the adjusted carrier with the sinusoidal modulation wave to obtain a modulating signal of the power unit, and controlling the power unit of the reactive power compensation device by the modulating signal to realize the capacitor voltage balance control of the compensation device. The capacitor voltage balance control method is used for balancing the capacitor voltage of the reactive compensation device.

The invention belongs to the field of compound eye micro-lenses and discloses a compound eye micro-lens array and a preparation method thereof, the preparation method comprises the following steps: preparing a compound eye substrate micro-lens array on a clean substrate; then dissolving the polymer in a volatile solvent to prepare a polymer solution, pouring the polymer solution on a substrate with a compound eye substrate microlens array, and forming a layer of uniform polymer film through spin coating; and placing the substrate in a closed container and standing for a period of time, obtaining a three-dimensional honeycomb-shaped ordered porous structure on the surface of the compound eye substrate microlens array after the solvent is completely volatilized, and preparing the compound eye microlens and further to make the compound eye microlens array. According to the invention, rapid and low-cost preparation of the compound eye microlens array can be achieved, and the high controllability of the shape, the diameter and the crown height of the bionic compound eye can be met.

The invention relates to a large-current constant-current ultraviolet light control circuit, which has a power processing circuit, a constant-current controller, a drive circuit, a constant-current circuit and an LED load sequentially connected; the input end of the constant-current circuit is also connected with a sampling circuit, The output terminals of the DC driving power supply circuit are connected; the output terminals of the sampling circuit are connected with the input terminals of the constant current controller; the output terminals of the sampling circuit are connected with the input terminals of the PI regulation circuit; the output terminals of the PI regulation circuit It is connected with the input terminal of the constant current controller; the constant current circuit includes a BUCK step-down topology circuit. The invention can stably output a large current of 25A, reduce the loss of the current, simplify the design of the driving circuit and save the cost.

The invention provides a driving method of a liquid crystal display. The driving method of the liquid crystal display comprises steps that a time schedule controller is used to output a source electrode enabling signal to a source electrode driver, and is used to output grid electrode enabling signal to a grid electrode driver; the source electrode driver is used to receive the source electrode enabling signal, and a duty ratio of a source electrode driving signal output to a source electrode line is reduced based on the source electrode enabling signal; the grid electrode driver is used to receive the grid electrode enabling signal, and a duty ratio of a grid electrode driving signal output to a grid electrode line is reduced based on the grid electrode enabling signal. The invention also provides the liquid crystal display and an electronic device. The liquid crystal display can be provided with a four-domain structure, and a quantity of electronic components is reduced based on improvement of color cast, and then an aperture ratio of a pixel is improved.