244results about How to "Realize digital control" patented technology

The digital profile grinder consists of system unit and auxiliary unit station. The system unit is one completely closed structure with machine body, multifunctional workbench, grinding frame, slide seat, CCD detector, and electric distributor. The auxiliary unit station has dust collector, cooler, and air balancing and braking controlling station. The present invention has image distinguishing technology adopted, and has integrated on-line machine tool detection, on-line compensation, on-line grinding wheel trimming and opened multi-axial digital control. It has at most eight shafts controlled, including seven servo rotary motor shafts and one linear servo motor shaft, and has at most six linked shafts, with the controlled shafts being in different combination. The present invention is suitable for machining various complicated parts.

The invention relates to an automatic frequency tracking method and a system for an ultrasonic transducer. A direct digital frequency synthesizer is used as a signal source, wherein the direct digital frequency synthesizer can be an independent integrated chip and also be achieved by the method that a digital part of a DDS is integrated in a site programmable logical element FPGA and then a digital-analog converter is additionally added. The design of the invention adopts a frequency sweeping and tracking policy, and an automatic frequency controller achieved by the programmable element controls the output frequency of the DDS according to a feedback signal sampled from the self transducer end so as to achieve the full digitization automatic frequency tracking and ensure that the ultrasonic transducer work near a resonance point all the time to obtain the optimal efficiency. A phase comparator utilizes a trigger to give out the arriving time difference of two riser edge signals of two input signals I ph and V ph aiming to the sensitive characteristics of the riser edge signals, and the sequence of the riser edge signals of the two input signals I ph and V ph is given out by a Dirrect pin.

The invention discloses an analog / digital configurable variable-gain amplifier, which comprises a variable-gain amplifier module VGA and an analog / digital configurable control circuit. The variable-gain amplifier module is formed by a plurality of variable-gain amplifiers and a fixed-gain amplifier in concatenation connection. The analog / digital configurable control circuit comprises an analog mode control circuit and a digital mode control circuit. A comparator and a charge pump of the analog mode control circuit detect the size of amplitude of an output signal, output an appropriate control voltage and feed back the control voltage to the VGA so as to regulate the gain of the VGA. The digital mode control circuit controls an internal switch circuit by means of an external signal, generates the control voltage by means of a decoder and an I-V converter according to an input signal provided by a digital baseband processing module chip and feeds back the control voltage to the VGA so as to change the gain of the VGA. The analog / digital configurable variable-gain amplifier can flexibly switch between an analog mode and a digital mode and is especially suitable for a radio-frequency front end circuit for different baseband chips.

The invention discloses a numerical-control intelligent wall painting machine. The numerical-control intelligent wall painting machine comprises a movable base, a vertical frame rod stretching device erected on the two sides of the base, a plastering device arranged on the vertical frame rod stretching device, an integrated control device arranged on the base and a power device arranged on the base. The plastering device comprises a plastering plate, a plaster hopper, a plaster hopper frame and a plaster hopper frame lifting device used for lifting the plaster hopper frame. The power device comprises a winding machine A and a winding machine B which are installed on the base. A touch screen controller is further arranged on the base through a supporting rod. The touch screen controller is in communication with the integrated control device. An angle adjusting device capable of automatically and intelligently adjusting the slant angle of stretchable vertical frame rods is arranged between the vertical frame rod stretching device and the base. By means of the numerical-control intelligent wall painting machine, many defects of an existing wall painting machine are overcome, the numerical-control intelligent wall painting machine is wide in application range, easy to operate, good in plastering quality, high in plastering efficiency and convenient to transfer, man-machine safety is guaranteed, time, labor and work are saved, and good economy popularizing value is achieved.

The invention discloses a radio frequency signal generating device. A control circuit is connected with a configuration port of a digital frequency synthesizer, a reference end of an operational amplifier of an automatic level control circuit and a tuning end of a voltage-controlled oscillator; a clock distribution circuit is connected with the digital frequency synthesizer, a frequency mixer and a comb-shaped spectrum generating circuit; the digital frequency synthesizer is connected with the clock distribution circuit and the frequency mixer; a local oscillation signal is connected with a switch; the switch is connected with a local oscillation input port of a quadrature modulating circuit; the output port of the comb-shaped spectrum generating circuit is connected with a third frequency mixer; the voltage-controlled oscillator is connected with the third frequency mixer, the frequency mixer and the control circuit; the frequency mixer is connected with a band-pass filter; the band-pass filter is connected with the automatic level control circuit; the output port of the automatic level control circuit is connected with the frequency mixer; and the frequency mixer is connected with the band-pass filter. The invention has digital control, good generality, low cost, flexible frequency setting and good stray and phase noise performance.

A full-digital fine-step high-accuracy controller for step motor is composed of single-chip microprocessor as control core, step motor control interface, power amplifier, and serial communication interface to host computer. Its control signal has standard TTL levels. Its highest frequency (1MH2) can be divided by 250, so increasing its control accuracy by 250 times.

The invention relates to a wind tunnel model folding deformation wing which is mainly used for measuring the pneumatic force of deformable aircraft in the wind tunnel dynamic test; traditional whole wing is divided into parts: a wing body, an internal wing, an external wing and the like; the wing body, the internal wing, the external wing, a connecting rod and a hinge shaft are coupled together with a driving mechanism and a driven mechanism controlled by a precise mechanical device; two mutually parallel longitudinal hinge shafts are arranged at the joint between the internal wing and the wing body and between the internal wing and the external wing; the hinge shaft of the internal wing and the wing body is a fixed shaft; the hinge shaft of the internal wing and the external wing is a driven shaft; the driving mechanism drives the internal wing to rotate correspondingly to the fixed shaft and drives the driven mechanism at the same time, thus leading the driven shaft to rotate correspondingly to the fixed shaft; the external wing arc plane always keeps a state parallel to the horizontal plane during the deformation running process of the wing. The wing folding deformation mechanism runs smartly and stably without noise, excellently bears the pneumatic force and pneumatic moment of the model, and realizes the digital control during the folding process, with precise positioning of the folding angle.

The invention discloses a pipeline cleaning robot and a control method. The pipeline cleaning robot comprises a base, a horizontal rotating disc, a spraying rod rotating seat, a spraying rod, a left side step motor, a right side step motor, a horizontal step motor, a curvature step motor, a vertical step motor, a spray rod rotating step motor and a control system, wherein a man-machine interaction system is arranged in the control system and sends instructions to a two-shaft and four-shaft moving control card, and each step motor arranged in the pipeline cleaning robot is respectively controlled through sending out pulses via the two-shaft and four-shaft moving control card, so each position of the spray head is regulated, and the pipeline cleaning is completed. A manual control method is characterized in that an operation interface of the man-machine interaction system is adopted, manual operation or input is carried out, the operation angle of each step motor is controlled, and the pipeline cleaning is completed in an artificial control way. The automatic control method has the advantages that the cleaning parameters are input, the operation of each step motor is automatically controlled through the control system, the pipeline cleaning is completed in an automatic control way, and the operation is very simple.

The invention discloses an intelligent medium-frequency high-voltage double-output direct current power supply for electric dust removal. The direct current power supply comprises a three-phase air switch with a tripper, a three-phase rectifier, a filter, a single-phase medium-frequency inverter, an air switch, a medium-frequency step-up transformer, a medium-frequency double half-wave rectifier,a first high-voltage direct current output sampling circuit, a second high-voltage direct current output sampling circuit, an isolating driver and a digital signal processing (DSP) controller, wherein the medium-frequency double half-wave rectifier of the direct current power supply is used for outputting two paths of direct current high voltage; the two paths of direct current high voltage are fed back to the DSP controller through two paths of sampling circuits; and a control signal is output to the single-phase medium-frequency inverter by the DSP controller to adjust frequency and amplitude. The direct current power supply has the characteristics of high output voltage, balanced power grid input and capability of greatly reducing pollution to a power grid and improving the utilizationefficiency of power; and a medium-frequency high-voltage silicon rectifier double-output transformer which is matched with the direct current power supply has the characteristics of small volume, light weight, low manufacturing cost and high efficiency. The direct current power supply has a wide application range and can be applied to construction of a new dust removal electric field, synergetic reconstruction of an old electric field and the like.

The invention discloses a digital space greenhouse. The digital space greenhouse is used for culturing crops in severe environment, particularly in deserts, dry areas, space and the like, and is characterized by comprising an aeration greenhouse, an outer frame, a sun shading device, a culturing device, an irrigation system, a temperature measurement system, a humidity measurement system, a nutrient solution measurement system and a moisture measurement system. The digital space greenhouse requires the outside of only sunshine for the growth of the crops and carbon dioxide for photosynthesis; various equipment and settings for optimal growth of the corps are arranged in the greenhouse; and moreover, the industrial Ethernet is used for monitoring and regulating the plant growth factors in real time and analyzing and storing various data, so digital control on the plant growth is realized. The digital space greenhouse overcomes the defects of the traditional vegetable greenhouse and has the characteristics of energy conservation, environmental protection, high production efficiency, high strength, strong wind / snow-resistant ability, high corrosion prevention performance, high light transmittance, long service life, convenient operation and management and the like.

The invention relates to the CCD driving technology, more particularly to a system for realizing drive of an EMCCD signal by a transformer. According to the invention, problems that a current driving method has high power and is difficult to be realized can be solved. An amplitude adjustment of an output signal of the system is carried out by changing a resistance value of a digital potentiometerin a first adjustable voltage transformer, so that an output voltage of the first adjustable voltage transformer is changed and thus a primary coil voltage of a high frequency transformer; therefore,a digital control on the output signal amplitude is realized; according to a digital parameter value received by the second adjustable transformer, a resistance value of a digital potentiometer in the second adjustable transformer is changed, thereby changing an output voltage value in a DC-DC boosted circuit; and a direct current polarization is provided for an RLC resonant circuit through a direct current level clamped circuit, so that the high and low levels of the output signal are still in a normal working range after the change of the amplitude value of the output signal each time. According to the invention, circuit power consumption and dependence on a high speed and high power device are substantially reduced.

The invention discloses an MIG welding power supply system based on STM32. The MIG welding power supply system comprises an inversion main circuit and a control circuit. The inversion main circuit comprises an input rectifying filter module, a high-frequency inverting module, a power transformation module and an output rectifying filter module which are sequentially and electrically connected. The control circuit comprises an SMT32 digital control module, a voltage-current detecting module, a fault protecting module, a man-machine interface module and a high-frequency drive module. The man-machine interface module realizes welding parameter giving through a digital pulse encoder. The MIG welding power supply system has the advantages that an STM32 chip is used to control the pulse MIG welding power supply system, system structure is simple, the control function is achieved through software, high anti-interference capability is achieved, and the problems that traditional pulse MIG welding power supply system is complex in structure, large in size, and inaccurate in parameter giving, and the like are solved.

The utility model relates to an adhesive force detection device for various adhesive type such as medical plaster and industrial adhesive and adhesive tape, comprising a motor positioned on a frame, an output gear positioned on a driving motor output shaft, a drive gear meshed with the output gear, a lead screw tightly fitted with the drive gear, a nut matched with the lead screw, a nut bracket fixed with the nut, wherein a tension sensor arranged on the nut bracket and connected with a pull rod of a detection roller. The pull rod and a detection roller bracket are connected with the detection roller. The detection panel is arranged on a groove base plate on the lower frame of the detection roller. A control device comprises a computer, an expansion board, a display, a printer, and a USB port connected with the computer. The utility model has the advantages of full digital control, automatic monitoring of sampling, analysis, and treatment of samples, and high detection precision.

Disclosed is a control system of an LLC converter synchronous rectifier tube. The control system comprises a voltage sampling circuit, a high-pass filter circuit, a PI compensation and effective valuedetection circuit and a control circuit which takes a microcontroller MCU as a core. A principle of circuit waveform oscillation caused by unavoidable parasitic inductance and parasitic capacitance in the circuit is utilized, and when an LLC converter works at high frequency, a drain source voltage VDS (SR) of the synchronous rectifying tube sends a change signal of the drain source voltage in aswitch-off period into the high-pass filter circuit and the PI compensation and effective value detection circuit through the sampling circuit to obtain an effective value amplifying signal of a drainsource voltage oscillation signal caused by parasitic parameters; and the control circuit which takes the microcontroller MCU as the core is adopted to compare the relation between a current value and a collected value in the last time, so that the conduction time of the synchronous rectification tube in the next cycle is changed, the synchronous rectifier tube can be switched off at the optimalswitch-off point, and the optimal efficiency operation of the synchronous rectifier tube can be realized.

The invention discloses a circuit structure of a narrow-pulse-width high-repetition-frequency pulse current source. The circuit structure is characterized by comprising an adjustable reference voltage input module (1), a current source module (2), an adjustable narrow pulse generating and shaping module (3), a high-speed selection module (4) and a current mirror module (5), wherein the adjustable reference voltage input module (1), the current source module (2) and the current mirror module (5) are electrically connected in sequence; and the adjustable pulse generating and shaping module (3), the high-speed selection module (4) and the current mirror module (5) are electrically connected in sequence. By adopting the circuit structure, the pulse width, the current magnitude and the pulse frequency can be adjusted. Moreover, the circuit structure has the advantages of narrow pulse width, high repetition frequency, high current, small overshoot and steep leading edge.

The present invention discloses a numerical control driving method and an apparatus for a superradiance light emitting diode. A step response method is used. At the beginning of starting the apparatus, a PID parameter which effectively controls a thermoelectric refrigerator is acquired and is used for a PID control algorithm. The deviation of a thermistor temperature signal and a stated temperature signal is compared. The signal is outputted to the thermoelectric refrigerator through the control of the PID. The thermoelectric refrigerator is controlled to generate a corresponding cooling capacity, so the work environment temperature of a SLD is improved and the temperature stability of the SLD is improved. The present invention is capable of being applicable for the superradiance light emitting diodes produced by various manufacturers and has strong applicability. In addition, the present invention is capable of adjusting a control parameter according to different work environments, so the problem that the control of the fixed parameter is not capable of adapting the environment temperature change is effectively overcome. The control accuracy is improved and the output power of SLD and the stability of a central wavelength are effectively improved.

The invention relates to the field of solid-liquid separation, in particular to a pressing mechanism of a vertical automatic filter press. Functions such as pulling open, closing, pressing, locking and the like of the filter plate of the traditional vertical automatic filter press are respectively completed by adopting multiple groups of cylinders. The pressing mechanism has the defects of complex structure, high cost, high frequency of failures, large difficulty of maintenance works, long time, influence on production, and the like. The invention provides an opening and closing self-locking pressing mechanism directly dragged by using a motor, and functions of pulling the filter plate open, closing the filter plate, pressing the filter plate, self-locking for pressure maintenance, rapidly opening and closing and the like of the opening and closing self-locking pressing mechanism are integrated into a whole. The opening and closing self-locking pressing mechanism is matched with high and new technical products such as a frequency converter motor, a PLC (Programmable Logic Controller), a touch screen, a frequency converter, a coder and the like, and executes a digital closed-loop automatic control. The invention has the advantages of simple, compact and reasonable structure, high efficiency, energy saving, less failure factors, stable and reliable work, low cost, durability, convenience for operation and use, high operability and the like, is beneficial to popularization, promotion and application of the vertical automatic filter press, and fully develops the special advantages.

The invention discloses a pneumatic control loop for dispensing. The pneumatic control loop comprises a main pipeline, a voltage stabilizing device is connected onto the main pipeline in series, a negative pressure pipeline is connected onto the main pipeline in parallel, the tail end of the negative pressure pipeline and an outlet of an electric proportional valve are jointly connected onto two input ports of a change valve, an outlet of the change valve is connected with an inlet of a dispensing needle tube, and a flow control valve, a vacuum device and a negative pressure switch are sequentially connected onto the negative pressure pipeline in series. The pneumatic control loop achieves digital control and digital display of pressure control and brings convenience to control of dispensing amount. The electric proportional valve is arranged in the loop so that a pressure value of a pressure loop is stabilized in a certain scope and dispensing accuracy is improved. The negative pressure pipeline is arranged to provide negative pressure for the dispensing needle tube when the dispensing needle tube does not dispense, so that glue liquid in the dispensing needle tube can not drop under action of gravity, raw materials are saved, and environment are protected.

The invention discloses a servocontrol system for an on-chip motor, which comprises a processing system, a system interface circuit and a motor driving system. The processing system is connected with the motor driving circuit through a system interface circuit, the motor driving system is connected with the motor, and the motor control instruction can be generated by the processing system and then can be sent to the motor driving system so as to drive and control the motor, the system interface circuit can achieve communication function with other peripheral devices simultaneously, and can transmit the status message of the motor which is collected by the motor driving system to the processing system. The control system can achieve the data control of various motor systems only through replacing the power MOS tube, and also achieve multi-channel control signal output.

The invention discloses a system and a layout method for airframe three-section involution and intersection hole machining. The system comprises an airframe gesture adjusting involution area and an airframe machining area and particularly comprises a foundation platform, 25-meter moving platform, auxiliary platforms, a robot moving platform, a machining center moving platform, a front airframe gesture adjusting platform, a middle airframe gesture adjusting platform, a rear airframe gesture adjusting platform, an upright type machining center, two horizontal type machining centers and two industrial robots. The left side and the right side of the foundation platform are respectively and symmetrically provided with one auxiliary platform. The layout method comprises the following steps of 1, each airframe location; 2, three-section airframe involution; 3, airframe intersection hole face machining; and 4, system part installation. The system for the airframe three-section involution and the intersection hole machining is high in flexible degree, compact in layout, high in assembly efficiency, high in automatic degree and capable of greatly improving gesture adjusting involution accuracy and machining accuracy.

The invention discloses a using method of a logistics collecting and stacking system suitable for freight containers. The using method includes the steps of loading and unloading preparation, binning operation, unloading operation and the like. According to the using method of the logistics collecting and stacking system suitable for the freight containers, automatic operation is completely controlled by a computer; after a data input and output port inputs the cargo binning position information of the freight containers, a stowage scheme, cargo packaging box stacking coordinate positions, cargo packaging box dimensions and internal dimension data information of the freight containers to the industrial control computer of an electric control device, the industrial control computer controls a supporting undercarriage to make coordinate movement front and back on longitudinal guide rails, and meanwhile a sorting mechanical arm, a ribbon conveyer and a forklift loader are in collaborative operation so that automatic binning or unloading operation can be achieved; and automatic operation is completely controlled by the computer, the defects of manual operation are avoided thoroughly, loading and unloading efficiency is high, and the using method is particularly suitable for cargo loading and unloading stacking operation of the freight containers in logistics storage container shipping.

The invention discloses an energy-saving control method for starting and stopping of circulating water field fans and aims at providing a cooling tower fan starting and stopping control technology. The method comprises the steps that firstly, actual operating parameters such as the environment temperature, the relative humidity, the atmosphere pressure, dynamic pressure of all points of the fans, circulating water inlet and outlet temperatures and the upper tower water volume are collected in real time by using special tools; secondly, according to the collected parameters, single-tower heat engineering calculation is conducted to obtain the water outlet temperature Tp of a tower when the fans are started and the water outlet temperature Tc of the tower when the fan is shut down; and finally, the water outlet temperatures in case of different numbers of fans are calculated according to the thermodynamic equilibrium, the corresponding relation between starting and stopping of the fans and the circulating water temperature is established, and by means of the automatic control technology, the purpose that the water supply temperature of circulating water is automatically adjusted through automatic starting and stopping of the fans is realized. According to the meteorological conditions and process conditions, scientific calculation, optimization and modification are conducted, the water outlet temperature of circulating water is stabilized, and the effects of stabilizing system operation, saving energy and reducing consumption are achieved.

The invention provides a high-power LED two-dimension light source, wherein an aluminum-base printed circuit board is directly welded or adhered with a high-power LED chip, the chip welded area is processed with a bowl-shape concave which circumference is furnished and plated with silver to form a light reflective area, the chip is arranged with a light reflective bowl with silver plated at inner surface to be fixed on the aluminum-base circuit board, a chip light outlet is packed with silicon-type transparent resin, in curvature shape, the light reflective bowl is covered with a lens unit, arranged with an electric connecting structure. The invention can be used to produce mono product or multiple beamed product, with standard distance connecting port, surface light source with low cost and high integration, better heat radiation, and uniform lighting effect, which can be used as general semi-conductor lighting source of variable lamps.

The related control method for LED used as decorative lighting lamp comprises: applying IR technology to remote control the LED, using MCU or ASIC to code or random control signal, arranging an external analog electric signal input interface and pre-set remote control coding data memory, using embedded-MPU to receive signal and generate digital PWC signal to control RGB current of every LED. This invention is benefit to build individual dynamic lighting atmosphere.

The invention provides a method and equipment of preparing flexible photo-anodes for dye-sensitized solar cells, and ensures an obtained semiconductor film free of cracks and superior in good uniformity and controllable thickness. The invention solves the problems of the prior art, such as long preparation time, poor repeatability, random distribution of local surface density of the semiconductor film, and high cracking risk. The flexible photo-anode is obtained by spray-coating of a conductive substrate by using a high-voltage electrostatic method and has good surface uniformity, and the surface semiconductor film doesn't produce cracks after random bending, thereby substantially realizing the flexibility. The preparation method is performed at normal temperature and pressure, without needing sinter process, thereby saving production energy and making it possible for nano-sized semiconductor materials with poor heat resistance to be applied in the field. The invention provides a new approach to improve the quality of the dye-sensitized solar cells.

The digital control system for arc spraying power belongs to surface technique field, which comprises a power transformer, a silicon controlled rectifier, a signal alignment circuit, a DSP, a Hall current sensor, a Hall voltage sensor, two photoelectric buffers, a H-bridge wire feed circuit, and a SCM; wherein, the signal alignment circuit sends signal into DSP; the DSP outputs trigger impulse signal after signal processing and calculating into buffer; the buffer outputs signal to control silicon controlled rectifier connected with power transformer. This invention improves stability, reliability and flexibility, and realizes information and digital control for spraying power.

The invention discloses a method for controlling the random vibration of an electrohydraulic servo system, which comprises the following steps: utilizing an acceleration power spectral density reference signal to design a filter III, filtering a white noise signal and taking the output of the filtration as an acceleration time-domain driving signal; utilizing a single-step prediction Kalman filter algorithm to online regulate the weights of a Kalman filter I and a Kalman filter II in real time and performing identification on a frequency response function of the electrohydraulic servo system and an impedance function of the Kalman filter I respectively; and constructing a filter IV based on the identification result of the impedance function of the Kalman filter II, filtering the acceleration time-domain driving signal and taking the output of the filtration as an acceleration input signal of the electrohydraulic servo system. The method for controlling the random vibration of the electrohydraulic servo system utilizes the filter III to filter the white noise signal to obtain the acceleration time-domain driving signal, which simplifies the process of generating the time-domain driving signal. The convergence property of the single-step prediction Kalman filter algorithm adopted in the invention ensures the convergence property of the real-time on-line iteration of power spectral density.

The invention relates to an intelligent household photovoltaic power generation control system. The working condition of the system is monitored by applying a digital control technology and an internet technology, information of the system is transmitted and reasonable and effective utilization of electric energy is controlled. Three energy sources of the system are photovoltaic power generating energy, energy stored in a battery and energy obtained from a power grid respectively; and an intelligent electricity housekeeper can monitor these energy data, reasonably analyzes the most appropriate electric energy flow of a home user and creates the biggest economic benefits for the home user. Meanwhile, the information of photovoltaic power generating capacity can be utilized by the system for analytical processing, a series of relevant information of illumination information, temperature information and the like is indirectly known, these information is analyzed by the intelligent electricity housekeeper to control a household intelligent device, all convenience is provided for the user and the user enjoys the pleasure brought by technology. The system is a supplement to a common household photovoltaic power generation system, and can assist the home user to reasonably and efficiently dispatch and use electric energy; and meanwhile, the digital control technology, the internet technology and a photovoltaic technology are fused and the intelligent household photovoltaic power generation control system has relatively high theoretical research and social practice value under the general background of the energy internet.

The invention relates to a material feeding mechanism of a flat plate type blister packaging machine. The material feeding mechanism comprises a lower clamp (50), an upper clamp (30) and a towing air cylinder (40); and also comprises a precision lead screw (100), a ball nut (20), a towing arm (60), a servo motor (70) and a synchronous belt (80); the precision lead screw (100) is fixedly arranged under the towing air cylinder (40); the ball nut (20) in contacted with the precision lead screw (100) is arranged on the precision lead screw (100); the ball nut (20) is connected with the towing arm (60); the towing arm (60) is connected with the lower clamp (50) and the upper clamp (30); and the servo motor (70) is connected with the precision lead screw (100) through the synchronous belt (80) and enables the precision lead screw (100) to rotate. The material feeding mechanism has the advantages that the structure is simple, and the digital control and adjustment can be realized.

The invention provides an LED (Light-Emitting Diode) light source system comprising a controller and an LED lighting device elastically connected with the controller. The LED lighting device comprises a power supply and an LED lamp panel and also comprises a singlechip, a digital to analog conversion circuit and a constant current control circuit; the controller transmits a control signal for confirming a brightness level value to the singlechip which stores the brightness level value in a digital signal mode and transmits the brightness level value to a digital to analog conversion circuit; the digital to analog conversion circuit converts the brightness level value into a voltage analogue quantity; and the constant-current control circuit converts the voltage analogue quantity into a stable current and controls the brightness of the LED lamp panel by the current. The LED light source system has simple circuit and easy operation and can accurately adjust the brightness of a light source.