40results about How to "To achieve the purpose of dimming" patented technology

The invention discloses a dimming circuit compatible with a silicon controlled rectifier dimmer and a control method. The dimming circuit includes an input voltage source, a rectification circuit, the silicon controlled rectifier dimmer, a dimming circuit and an output circuit, wherein the input voltage source is connected with the rectification circuit and the silicon controlled rectifier dimmer respectively, the rectification circuit is connected with the dimming circuit, the dimming circuit is connected with the output circuit, and the output circuit includes an isolation transformer, a switch tube, a third sampling resistor, a flyback diode, a filtering capacitor and an output LED load. The dimming circuit compatible with the silicon controlled rectifier dimmer is characterized in that the dimming circuit includes a sampling circuit used for sampling the phase-cut angle of the silicon controlled rectifier dimmer, a control and logic circuit which is controlled by the phase-cut angle, and a phase-cut angle setting circuit which can control the switching on and switching off of the switch tube according to the status of an inputted phase-cut angle. With the dimming circuit compatible with the silicon controlled rectifier dimmer of the invention adopted, the problem of flicker appearing in a traditional dimming process can be effectively solved, and at the same time, a dimming purpose can be achieved.

The invention discloses a single live wire power-getting circuit. The single live wire power-getting circuit comprises a silicon controlled rectifier circuit, a switching mode power supply circuit and a micro control unit (MCU) circuit, wherein the silicon controlled rectifier circuit gets power from a live wire; an input end loop of the switching mode power supply circuit is connected with the output end of the silicon controlled rectifier circuit; the switching mode power supply circuit outputs stable direct voltage with high loading capability to the MCU circuit; the input end of the MCU circuit is connected with the signal output end of the silicon controlled rectifier circuit; and the output end of the MCU circuit outputs a sequential control signal to the signal receiving end of the silicon controlled rectifier circuit to adjust a conduction angle of the silicon controlled rectifier. In the invention, the zero crossing point of alternating current is detected in real time through the MCU circuit, so that a control signal is transmitted, control over the conduction angle of the silicon controlled rectifier is realized, and the aim of regulating load light is fulfilled. For the MCU circuit, the conduction angle of the silicon controlled rectifier can be controlled through a keypad and wireless data to fulfill the aim of regulating the light. The single live wire power-getting circuit can ensure the stable operation of the rear-end switching mode power supply and provide stable voltage for rear-end equipment for operation at the same time of light regulation.

The invention discloses a dimming circuit compatible with a silicon controlled rectifier dimmer and a control method. The dimming circuit includes an input voltage source, a rectification circuit, the silicon controlled rectifier dimmer, a dimming circuit and an output circuit, wherein the input voltage source is connected with the rectification circuit and the silicon controlled rectifier dimmer respectively, the rectification circuit is connected with the dimming circuit, the dimming circuit is connected with the output circuit, and the output circuit includes an isolation transformer, a switch tube, a third sampling resistor, a flyback diode, a filtering capacitor and an output LED load. The dimming circuit compatible with the silicon controlled rectifier dimmer is characterized in that the dimming circuit includes a sampling circuit used for sampling the phase-cut angle of the silicon controlled rectifier dimmer, a control and logic circuit which is controlled by the phase-cut angle, and a phase-cut angle setting circuit which can control the switching on and switching off of the switch tube according to the status of an inputted phase-cut angle. With the dimming circuit compatible with the silicon controlled rectifier dimmer of the invention adopted, the problem of flicker appearing in a traditional dimming process can be effectively solved, and at the same time, a dimming purpose can be achieved.

The invention discloses an LED lighting driving circuit and a method by using a compatible silicon controlled light adjuster to adjust light, an input signal is connected with a silicon controlled light adjusting circuit and a rectifier bridge circuit in series, an output anode of the rectifier bridge circuit is connected with a signal sampling and filtering circuit which is connected with a voltage controlled current source and a loaded LED in series; the output anode of the rectifier bridge circuit is connected with an electric leakage protection circuit; the signal sampling and filtering circuit is characterized in that a normal phase input end of a comparator is connected with the positive end of a benchmark voltage, the negative end of the benchmark voltage is connected to the ground, an output end of the comparator is connected an input end of a phase inverter, the output end of the phase inverter is connected with the input end of a low-pass filter, and the output end of the low-pass filter is connected with a control terminal of the voltage-controlled current source. The LED lighting driving circuit by using the compatible controlled silicon light adjuster to adjust light adopts a silicon controlled electric leakage absorbing circuit to enable the sampled silicon controlled light adjusting signal to be accurate and stable, and the light adjusting effect of the loaded LED is good.

The invention discloses a novel intelligent high-precision LED driving power source which comprises an alternating-current input rectifying filtering unit, a flyback DC / DC power source conversion unit, a secondary rectifying unit, a ZIGBEE dimming unit, a MAX16822 constant current unit, a voltage sampling unit, a current Hall sampling unit, an MSP430F149 single chip microcomputer unit, an auxiliary temperature sampling module, a liquid crystal display module, a keyboard input module, a GSM wireless communication module, an auxiliary power source module of a single chip microcomputer, an I / O extension module, a crystal oscillation module and an auxiliary protection circuit. The novel intelligent high-precision LED driving power source has the advantages that the circuit structure is novel, the power source efficiency is high, the output current precision is higher due to the adoption of a MAX16822 constant current chip, the digitalized degree and the intelligentized degree are high, the MSP430F149 single chip microcomputer fully participates in the closed-loop control over the output current and the output voltage, the man-machine interaction is strong, and due to the fact that an ultracrystalline magnetic core is adopted in a transformer, the size is small.

The invention provides a PWM (pulse width modulation) dimming method for an LED (light-emitting diode). The PWM dimming method comprises the following steps: starting a first timer in an interrupt mode and a second timer in a free counting mode of a single chip microcomputer; making statistics on the number of interrupts of the first timer and count values of the second timer during the brightness change stage of the LED; performing at least one zero clearing on the count values of the second timer during the statistical process; and comparing the number of interrupts with the count values in real time, and outputting a PWM wave the level value of which changes along with the comparison result, wherein the PWM wave is applied to the LED for regulating the brightness of the LED. The invention further provides a dimming device corresponding to the method. The PWM dimming method and device for the LED disclosed by the invention can solve the problem of few PWM output ports of the existing cheap single chip microcomputer.

A method for inhibiting the influence of LED nonlinear distortion on visible light communication performance. The method mainly comprises the following steps: (1) carrying out modulation symbol sequence mapping, and satisfying the Hermitian symmetry by an output signal ; (2) multiplying the mapping signal by a scale change factor; (3) carrying out IFFT, then carrying out amplitude limiting decomposition on the optical OFDM symbol, and obtaining a plurality of decomposition symbols with small amplitudes; (4) decomposing symbol serial framing; (5) sequentially and serially receiving all the optical OFDM symbols in one frame by a receiving end, and respectively delaying until the symbols are aligned; and (6) adding the corresponding bits, and combining into an optical OFDM symbol. Accordingto the method, the average power of the optical OFDM symbols is easy to regulate and control. The synchronization is easy, and the implementation is easy. The deployment is easy.

The invention discloses an adjustable photocontrol circuit of an LED (light-emitting diode) lamp, which comprises a power supply conversion circuit capable of connecting an LED lamp load and a PWM (pulse width modulation) control circuit and is characterized in that the power supply conversion circuit comprises a voltage transformation circuit, a rectification filter circuit and an LED load control circuit, the output end of the PWM control circuit is sequentially connected with a diode D3 and a resister R3 in series, and the output end of the resister R3 is connected with a reference controlpoint (A) of the LED load control circuit. The standard control point (A) is an anodic control end of an opticalcoupler, a control end of a reference voltage source or a control end of a comparator. The PWM control circuit is powered by an auxiliary power supply or connected with the output end of the power supply conversion circuit. Because of the advantages, The invention can be applied to a similar laden control circuit of the LED lamp and the like.

The invention discloses an electronic ballast which comprises a filter circuit, a rectification circuit, a phase shedding detection circuit, a power factor correction circuit, a resonance circuit and a control circuit. The filter circuit and the rectification circuit are connected with an alternating power supply. One end of the phase shedding detection circuit is connected with an output end of a rectification circuit, and the other end thereof is connected with the control circuit. The power factor correction circuit is connected with the output end of the rectification circuit and comprises a half-bridge which consists of two switch transistors connected in series. One end of the resonance circuit is connected with the output end of the half-bridge, and the other end thereof is connected with a lighting tube. The control circuit is connected with control ends of the switch transistors, and the control circuit controls the switch transistors to be switched on and off and the output frequency of the half-bridge by a detection signal of the phase shedding detection circuit. The electronic ballast has simple circuit, low cost and good dimming effect. The invention also discloses a universal lamp holder of an energy saving lamp with the electronic ballast and a dimming method used by the electronic ballast.

The invention relates to an air filtering composite heat insulating and light adjusting window. The air filtering composite heat insulating and light adjusting window comprises a composite heat insulating profile window frame, a window type air filtering valve and hollow light adjusting glass. The composite heat insulating profile window frame comprises profile transverse frames, profile vertical frames and profile middle columns. The window type air filtering valve comprises a filtering valve frame body, an alloy magnetic conductive air curtain supporting net, a filtering core, electromagnets, permanent magnets, a wind preventing curtain and a wind preventing curtain unwinding mechanism. The hollow light adjusting glass comprises pieces of tempered glass, a multistage light adjusting film and a multistage light adjusting film sealing and tensioning mechanism. According to the air filtering composite heat insulating and light adjusting window, air entering into a room from the outside of the room is filtered, and indoor and outdoor air convection and filtering are achieved; meanwhile, the amount of ultraviolet light, visible light and near-infrared light of sunlight shining into the room and the ratio of the ultraviolet light to the visible light to the near-infrared light of sunlight shining into the room are controlled through up-down moving of the multistage light adjusting film, and the situation that optical parameters of the hollow glass are adjustable is achieved; and in addition, the wind pressure resistance, the airtight performance, the watertight performance, the heat preservation performance, the sound insulation performance and the heat insulation performance of a window body of the air filtering composite heat insulating and light adjusting window are higher than national standards.

The invention discloses an LED (Light-Emitting Diode) dimming drive circuit, comprising a dimming control unit, a dimming output unit and a subsequent-flow loop unit, wherein the dimming control unit is electrically connected between a power supply and the dimming output unit, and is used for outputting PWM (Pulse Width Modulation) pulse; and the PWM pulse passes through the dimming output unit and controls the brightness of an LED through the subsequent-flow loop unit so as to realize dimming of the LED. The LED dimming drive circuit provided by the invention has the advantages that an integrated dimming control chip is adopted, the A / D values of a PB0 pin and a PB4 pin are compared by utilizing the chip, the output pulse width of a PB3 pin is readjusted after comparison, and in such circulating mode, the dimming purpose is achieved.

The invention provides a light dimming circuit for a linear high-voltage LED driver. The light dimming circuit comprises a bridge rectifier, at least two sections of LED strings, a driving control IC, a driving switch, a PWM control switch and a PWM signal input end, wherein positive electrodes and negative electrodes of the LED strings are in serial connection in an end-to-end mode. After the PWM control switch receives PWM signals, the time proportion of on-off time of the driving switch is controlled to adjust the time ratio between luminous time and nonluminous time of the LED strings to finally achieve the purpose of dimming light. The light dimming circuit achieves the light dimming function of LED lighting lamps by using the linear high-voltage LED driving scheme.

The invention relates to a cold-cathode fluorescence lamp capable of regulating the luminance, with simple structure, suitability for continuously regulating the luminance and better stability. The cold-cathode fluorescence lamp comprises a luminance regulating drive circuit, wherein the luminance regulating drive circuit comprises a luminance regulator, a rectification circuit, a high frequency inversion circuit, a boosted circuit and a luminance regulating circuit, the luminance regulator is connected with an alternating current power supply, the alternating current output end of the luminance regulator is connected with the alternating current input end of the rectification circuit, the direct current output end of the rectification circuit is connected with the direct current input end of the high frequency inversion circuit, the high frequency alternating current output end of the high frequency inversion circuit is connected with the boosted control end of the boosted circuit, and the power supply output end of the boosted circuit is used for connecting with the power supply input end of the cold-cathode lamp; and the direct current output end of the rectification circuit isconnected with the power supply input end of the luminance regulating circuit, the feedback voltage output end of the boosted circuit is connected with the feedback voltage input end of the luminanceregulating circuit, and the luminance regulating control output end of the luminance regulating circuit is connected with the inverted frequency control end of the high frequency inversion circuit.

The invention relates to a dimming circuit. The dimming circuit comprises an alternating current-direct current conversion circuit and a direct current-alternating current conversion circuit, wherein alternating current-direct current conversion circuit is used for converting alternating-current voltage into direct-current voltage, and the direct current-alternating current conversion circuit is used for converting the direct-current voltage into the working voltage of a lamp. The direct current-alternating current conversion circuit comprises a drive circuit used for providing drive voltage between a reference contact and a control contact and a conversion circuit which is coupled to the drive circuit and comprises at least one switch. The dimming circuit has the advantages that at least one electric parameter between the reference contact and the control contact is adjusted to change the working frequency of the direct current-alternating current conversion circuit so as to adjust the brightness of the lamp; each electric parameter selected from one inductance parameter and one capacitance parameter; the dimming circuit provides simple circuit connection, and dimming is achieved by changing the electric parameters between the reference contact and the control contact.

The invention discloses an exponential dimming method and system of a light-emitting diode. The method comprises the steps of acquiring dimming control codes of Nbit; judging all numerical codes, obtaining a corresponding coefficient of [(Imax / Imin)^(1 / codemax)]^(2^i) of the ith numerical code when the ith numerical code is 1, and obtaining a corresponding coefficient of 1 when the numerical codeis 0; according to a formula IDac=I, calculating * (a corresponding coefficient of the (N-1)th numerical code *...* a corresponding coefficient of the zeroth numerical code), and performing calculation to obtain an adjusting current; and performing dimming on the light-emitting diode according to the adjusting current. By combining the formula IDac=I, the * (the corresponding coefficient of the (N-1)th numerical code *...* the corresponding coefficient of the zeroth numerical code) is calculated, and for the dimming control codes of the Nbit, the adjustment current can be obtained through multiplication calculation of the N-time coefficients, so that the dimming method is simpler, fewer hardware resources can be occupied, and meanwhile, the precision of the dimming current is ensured to berelatively high.

The gas discharge lamp is composed of glass bulb, electrical arc tube, bracket, guiding wire, stem, lamp holder, getter, small bracket and connecting piece. There is arc tube in small power, which is connected to the electrical arc tube in parallel, on the other side of the bracket. Characters are that energy saving controller in use for gas discharge lamp in duplexing powers is composed of current / voltage detection A, circuit B for processing signal and generating control signal, and power adjustable ballast C. A control signal is generated to control power adjustable ballast C after data process is carried out for signal detected by the current / voltage detection A. Under precondition of not losing light efficiency, the invention realizes modulation of strong light and weak light. The disclose lamp and general lamp in single power can use same bulb, holder, trigger and power adjustable ballast so as to lower cost and be in favor of reconstructing current illumination.

The present invention relates to a LED illuminating system used for 3LCD projecting systems, comprising a cooling device, LED driving and controlling circuit boards, collimation components, tricolor light emitting diode LEDs, tricolor LCD panels, and a light splitting and combined prism X-Cube. Three types of light emitting diode LEDs of red, green and blue are respectively arranged on the cooling device, the LED driving and controlling circuit boards; each LED illuminates a corresponding LCD panel through a collimation component; each LCD panel is arranged in a fixed square groove; and the light which penetrates each LCD panel is projected on the display screen for imaging through a projecting system after combining in X-Cube. The present invention is mainly used in 3LCD projecting systems to acquire projecting light sources of high brightness, good uniformity, rich color and good flexibility.

A dimming circuit comprises a multipath input end, an alternating current-direct current conversion circuit, a voltage adjusting circuit, a direct current-alternating current conversion circuit and a control circuit, wherein the multipath input end is coupled to an alternating-current power supply and used for receiving alternating-current voltage, the alternating current-direct current conversion circuit is used for converting the alternating-current voltage into first direct-current voltage; the voltage adjusting circuit is used for converting the first direct-current voltage into second direct-current voltage, and the voltage adjusting circuit comprises a first switch; the direct current-alternating current conversion circuit is used for converting the second direct-current voltage into the working voltage of a lamp; the control circuit is coupled to the multipath input end and provides a control signal to the first switch. The dimming circuit has the advantages that the coupling modes of the multipath input end and the alternating-current power supply are converted to adjust the control signal so as to change the duty ratio of the first switch and adjust the brightness of the lamp; the dimming circuit is simple in electronic element connection, and the multipath input end is selectively coupled to the input end of the alternating-current power supply to achieve dimming.

The present invention provides a dimming and toning circuit. The circuit comprises: a switching circuit used for performing switching among an intelligent mode, a microwave mode and a manual mode according to a switching instruction; a first driving circuit which acquires a first adjusting signal to adjust the current value of the output end of the first driving circuit; and a second driving circuit which acquires a second adjusting signal to adjust the current value of the output end of the second driving circuit. In the intelligent mode, a cold white light load performs power adjustment according to the current value output by the first driving circuit, and a warm white light load performs power regulation according to the current value output by the second driving circuit; in the microwave mode, the cold white light load and the warm white light load perform power adjustment according to the current value output by the second driving circuit; and in the manual mode, the power of the cold white light load and the power of the warm white light load are adjusted according to a dimming instruction. The dimming and toning circuit has the beneficial effects that: the circuit structure is simple, the cost is low, a user can select the operation mode of dimming and color modulation, and the use experience is improved.

The invention relates to the technical field of medical treatment, in particular to an automatic clamping dimming type intelligent film viewing device for the imaging department, which comprises a CT film, an electroluminescent panel, a processing controller and a wireless remote control module, and further comprises a box-shaped base, and the processing controller and the wireless remote control module are both fixed on one side in the box-shaped base; a round hole is formed in one side of the box-shaped base, the rotating shaft can rotate on the inner side of the round hole, one end of the rotating shaft can rotate on one side in the box-shaped base, and an automatic rotation adjusting assembly is arranged between the rotating shaft and the box-shaped base. Through the arrangement of the CT film, the electric light-emitting plate, the processing controller, the box-type base, the rotating shaft, the guide sleeve, the telescopic column, the supporting box, the cover plate, the lower L-shaped frame, the upper L-shaped frame, the lower connecting L-shaped frame, the upper connecting L-shaped frame, the face recognition camera and the photosensitive sensor, the face tracking, rotating adjustment, lifting adjustment, intelligent dimming, automatic clamping, automatic flattening and automatic resetting functions are achieved.

The invention discloses an environment-friendly temperature-controlled dimming glass and a preparation method thereof. It comprises a first glass sheet and a second glass sheet that are consistent in structure and are hermetically bonded. The first glass sheet is provided with a hydrophilic region and a hydrophobic region. The two glass sheets are provided with a hydrophilic area and a hydrophobic area, and the hydrophilic area is adjacent to the hydrophobic area. The hydrophilic area and the hydrophobic area on the first glass sheet are located on the surface layer close to the second glass sheet. The hydrophilic area on the second glass sheet The water area and the hydrophobic area are located on the surface layer close to the first glass sheet, and a reflective condensation drop layer is arranged in the hydrophilic area; the structure is reliable, the preparation is simple, the cost is low, and the performance is good, and the saturated humidity of the air at different temperatures is different. Features, through the change of external temperature to change the condensation and evaporation of water vapor in the air, and the condensed droplets can refract light, and then adjust the luminosity of the glass, reduce the price of the dimming glass, and make the dimming glass more environmentally friendly.

The invention discloses a lamp power control circuit. One end of an inductive ballast (L0) of a current regulating circuit (1) is connected with one end of a first switching tube (K1). A center tap is connected with one end of a second switching tube (K2). The other end of the second switching tube (K2) is connected with the other end of the first switching tube (K1). A lamp starting circuit is further comprised, wherein the lamp starting circuit is connected on the front end or the rear end of the current regulating circuit (1) and composed of a lamp bulb (HID) and a starter(3) for starting the lamp bulb (HID). A controller (2) is further comprised, wherein the controller (2) is connected with the first switching tube (K1) and the second switching tube (K2) separately. By regulating the time of the current flowing from the inductive ballast center tap, the average value of the current flowing through the lamp can be regulated, so that the purpose of lamp power stepless regulation can be realized. The controller is used to calculate the lamp power by measuring the lamp voltage and the lamp current, and perform closed-loop regulation according to the lamp power, so that the purpose of constant power control can be realized.

The invention discloses a Stirling solar energy optically focused disc light modulation system comprising a disc rack and a disc arranged on the disc rack to form a disc surface; the disc rack is provided with a light modulation hand (100); the front end of the light modulation hand (100) is connected with a disc adjusting rod, and the rear end is connected with a light modulation controller (200); the disc surface focus point is provided with a light modulation color plate (400), and the far side is provided with a telescope (500); the disc rack, the light modulation color plate (400) and the telescope (500) are arranged on a same straight line; a light modulation handle (600) is arranged by the telescope (500), and connected with the light modulation controller (200) through a router (700). The system uses the telescope to artificially observe the projection of the light modulation color plate on the mirror, uses the handle to rotate the light modulation hand (100), and controls the disc to move back and forth, thus realizing light modulation purpose.

The invention relates to an air filtration composite heat-insulation dimming window, comprising a composite heat-insulating profile window frame, a window-type air filter valve and an air-conditioning glass; The profile center column, the window air filter valve includes a filter valve frame, an alloy magnetic conductive air curtain support net, a filter element, an electromagnet, a permanent magnet, a windproof curtain and a windproof curtain rolling mechanism, and the middle air-conditioning light glass includes tempered glass. Glass, multi-level dimming film and multi-level dimming film sealing tension mechanism. The invention can filter the air entering the room from the outside to realize the convective filtration of the indoor and outdoor air; at the same time, the multi-level dimming film moves up and down to control the amount and amount of ultraviolet, visible and near-infrared light in the sunlight entering the room. Proportion, the optical parameters of the insulating glass can be adjusted, and the wind pressure resistance, air tightness, water tightness, thermal insulation performance, sound insulation performance and thermal insulation performance of the window are higher than the national standards.

A method for suppressing the influence of LED nonlinear distortion on the performance of visible light communication. The main steps are: (1) mapping a modulation symbol sequence, and the output signal satisfies Hermitian symmetry; (2) multiplying the mapped signal by a scale change factor; (3) ) to perform IFFT, and then slice and decompose the optical OFDM symbols to obtain multiple decomposed symbols with smaller amplitudes; (4) decompose the symbols serially framing; (5) the receiving end serially receives all the optical OFDM symbols in a frame in sequence , respectively delayed until the symbols are aligned; (6) the corresponding bits are added and combined into an optical OFDM symbol. The invention is easy to control the average power of the optical OFDM symbol, easy to synchronize, simple to realize, and easy to deploy.

The invention discloses an adjustable photocontrol circuit of an LED (light-emitting diode) lamp, which comprises a power supply conversion circuit capable of connecting an LED lamp load and a PWM (pulse width modulation) control circuit and is characterized in that the power supply conversion circuit comprises a voltage transformation circuit, a rectification filter circuit and an LED load control circuit, the output end of the PWM control circuit is sequentially connected with a diode D3 and a resister R3 in series, and the output end of the resister R3 is connected with a reference controlpoint (A) of the LED load control circuit. The standard control point (A) is an anodic control end of an opticalcoupler, a control end of a reference voltage source or a control end of a comparator. The PWM control circuit is powered by an auxiliary power supply or connected with the output end of the power supply conversion circuit. Because of the advantages, The invention can be applied to a similar laden control circuit of the LED lamp and the like.

The invention provides a dimming circuit and a light emitting device. The dimming circuit comprises an input end, a switch module and a constant current module. The input end is used for being electrically connected with a power module. The first connecting end of the switch module is electrically connected with the input end, the second connecting end of the switch module is used for being electrically connected with the light emitting module, and the switch module is used for receiving the modulation signal and repeatedly connecting or disconnecting the electric connection between the input end and the light emitting module according to the modulation signal, so that the duty ratio of the current input to the light emitting module by the power supply module is adjusted. The constant current module is connected in series in a loop where the light emitting module is located, and is used for adjusting the amplitude of the current input to the light emitting module by the power supply module. The duty ratio of the current input to the light emitting module by the power supply module is adjusted through the switch module, so that the purpose of dimming is achieved, and fine dimming of the light emitting module under the requirement of low brightness can be realized.

Full-automatic dimming detection equipment for a motorcycle headlamp comprises a workbench, a clamp device and a socket are arranged at the front part of the workbench, the clamp device comprises a bottom plate, the bottom plate is fixed on the workbench, a moving mechanism, a clamping mechanism and a lamp body profiling block are arranged on the bottom plate, the headlamp is arranged on the lamp body profiling block and is fastened by the clamping mechanism, and the lamp body profiling block is fixed on the workbench. A dimming screw is arranged in the headlamp, an adjusting sleeve is arranged on the moving mechanism and matched with the dimming screw, a detection frame is arranged on the rear portion of the workbench, a Fresnel lens is arranged in a front side plate of the detection frame, an image collector is arranged on the front side plate of the detection frame, and a projection plate is arranged on a rear side plate of the detection frame. The top of the detection frame is provided with a display and a PLC controller, a power supply frame is arranged below the workbench, a power supply is arranged in the power supply frame, the power supply is connected with an image collector, a socket, the display and the PLC controller, and during working, the headlamp is connected with the socket, and the headlamp is lightened to irradiate towards the Fresnel lens.

An embodiment of the invention provides a dimming circuit. The dimming circuit comprises a plurality of constant current power supplies connected in parallel, a control unit and switches which are connected with the constant current power supplies in series respectively, and the control unit is connected with the switch. The constant current power supplies of the same type are adopted in parallel,so that a plurality of constant current power supplies with output currents based on a preset rule are connected in parallel to form a general power supply; each constant current power supply is connected with a switch, and the output total current can be controlled by controlling the switches, so that the purpose of dimming is achieved, the cost is low, and the dimming performance is stable.

The invention discloses a universal type gas discharge lamp dimming apparatus. The dimming apparatus is arranged at the input front end of a lamp; the dimming apparatus is a controllable power regulator; the controllable power regulator comprises an electronic transformer and a single chip microcomputer; the electronic transformer is connected with the single chip microcomputer; the controllable power regulator is connected with a ballast through a conversion circuit; the conversion circuit is divided into two paths, wherein one path converts alternating current mains supply into a direct current to be output while the other path converts a direct current voltage into alternating current square wave to be output; the conversion circuit automatically switches circuits according to types of the ballasts; if the ballast is an electronic ballast, the direct current is output; and if the ballast is an inductive ballast, 50HZ alternating current square wave is output. The dimming apparatus disclosed in the invention is a totally electronic control apparatus, and has the characteristics of high power factor, stable output power, capability of realizing remote control and prolonging service life of the lamp, high efficiency and the like.