123results about How to "Change the output power" patented technology

The invention discloses a system and a method provided with calibration transmitting and receiving channels for real-time monitoring of multichannel transmitting and receiving delays. The method comprises the following steps of measuring a sum of closed loop delays of a calibration transmitting channel and a calibration receiving channel, and subtracting an absolute delay of the calibration transmitting channel from the sum of the closed loop delays to obtain an absolute delay of the calibration receiving channel; measuring a sum of the closed loop delays of a reflector inter-satellite link transmitting channel and the calibration receiving channel and a sum of the closed loop delays of a phased array inter-satellite link transmitting channel and the calibration receiving channel, and subtracting the absolute delay of the calibration receiving channel from the sums of the closed loop delays to obtain absolute delays of the reflector inter-satellite link transmitting channel and the phased array inter-satellite link transmitting channel; and measuring a sum of the closed loop delays of the calibration transmitting channel and a reflector inter-satellite link receiving channel and a sum of the closed loop delays of the calibration transmitting channel and a phased array inter-satellite link receiving channel, and subtracting the absolute delay of the calibration transmitting channel to obtain absolute delays of the reflector inter-satellite link receiving channel and the phased array inter-satellite link receiving channel. According to the system and the method, the real-time monitoring of the multichannel transmitting and receiving delays is realized, and the system and the method have the characteristic that the measured absolute delays of the transmitting channel and the receiving channel are accurate.

When a position detector detects that the position of a spot on a projection plane designates a non-projection region, the level of a driving signal of a laser is corrected. Specifically, the correlation between the quantity of laser light detected by a light-receiving portion and the level of the driving signal of the laser in accordance with prescribed data is detected. Then, the characteristic value of the laser indicated by the detected correlation is compared with the characteristic value at room temperature stored beforehand to indicate the correlation between the quantity of light emitted by the laser at room temperature and the level of the driving signal. Then, based on the comparison result, the level of the driving signal of the laser in accordance with image data is corrected.

The invention discloses an electro-hydraulic system for recycling and releasing the potential energy of an engineering machinery. The electro-hydraulic system comprises a control system, a power source, a performing mechanism, a switching mechanism and an energy recycling releasing mechanism, wherein the control system comprises a controller, a first pressure sensor, a second pressure sensor, a third pressure sensor and a fourth pressure sensor; the power source comprises an engine, a main variable pump and an oil tank; the performing mechanism comprises a lifting hydraulic cylinder; the switching mechanism comprises a multiway valve and a pilot control handle; and the energy recycling releasing mechanism comprises an energy accumulator, a first liquid control two-position three-way valve, an electromagnetic two-position three-way valve and a variable pump-motor. With the adoption of the electro-hydraulic system for recycling and releasing the potential energy of the engineering machinery, when the working condition of the engineering machinery is down, a lot of gravitational potential energies can be recycled and is used for driving the main pump, so that the consumption power of the engine is lowered, the energy waste is reduced, and the work efficiency of the engineering machinery is improved.

The invention discloses an interconnection line-free secondary control method of parallel inverters in a micro grid and belongs to the coordinated control field of parallel inverters in a micro grid. According to the method of the invention, the inverters monitor the frequency and voltage amplitude of a system in real time; when the deviation of the frequency or voltage is large, the inverters estimate the power requirement of a load and load power which is required to be borne by the inverters in an on-line manner according to monitored frequency and voltage information, and then calculate new droop characteristics; and therefore, the inverters can automatically adjust the deviation of the droop characteristics of the inverters, and the output power of the inverters can be changed, and the recovery of the frequency and voltage amplitude of the system can be facilitated, and the deviation of the frequency and voltage amplitude caused by droop control can be effectively eliminated. The method does not depend on communication between the inverters. With the method adopted, accurate control on the frequency and voltage amplitude can be realized, and at the same time, equipartition of load power, which is in direct proportion to the capacity of the inverters, can be obtained between the inverters, and excellent references can be provided for engineering application.

When a position detector detects that the position of a spot on a projection plane designates a non-projection region, the level of a driving signal of a laser is corrected. Specifically, the correlation between the quantity of laser light detected by a light-receiving portion and the level of the driving signal of the laser in accordance with prescribed data is detected. Then, the characteristic value of the laser indicated by the detected correlation is compared with the characteristic value at room temperature stored beforehand to indicate the correlation between the quantity of light emitted by the laser at room temperature and the level of the driving signal. Then, based on the comparison result, the level of the driving signal of the laser in accordance with image data is corrected.

The invention discloses an electric bicycle center shaft force moment sensing device which comprises a center shaft arranged in a five-way tube through a bearing, a crank fixed on the center shaft and a crankset sleeved on the center shaft. The electric bicycle center shaft force moment sensing device is characterized by further comprising a force moment sensing Hall component. The component comprises an elastic twist component connected with the center shaft and the crankset. Force moment sensing magnetic steel generating circumferential displacement through twist of the elastic twist component is fixed on the elastic twist component. The electric bicycle center shaft force moment sensing device further comprises a force moment sensing Hall element corresponding to the force moment sensing magnetic steel and fixed on the center shaft. The force moment sensing Hall element is electrically connected with a motor control circuit board through a collecting ring wire outlet device arranged between the center shaft and an inner wall of the five-way tube and the motor control circuit board is electrically connected with a motor. The electric bicycle center shaft force moment sensing device is high in flexibility and accuracy and capable of detecting static torque and dynamic torque, guaranteeing zero start when an electric bicycle is ridden and maintaining stable riding performance.

This invention relates to a self-restructing plasma antenna including a column container, inert gases, a RF excitation antenna, a RF excitation source, a signal coupler, a feeding port and an earth plate characterizing that the column container is filled with inert gases, the source and the antenna are used in exciting and maintaining the plasma, in which, the excitation antenna is set in the inside or outside of the column container, its lead out wire is connected with the RF excitation source, the signal coupler is used to couple the signal to the plasma antenna set out of the container, the lead out wire is connected with the internal conductor of the feeding port and the outer conductor is connected with the earth plate.

The invention relates to a direct fuel cell energy storage and supply system, and in particular relates to a parallel direct fuel cell energy storage and supply system based on a liquid hydrogen storage material. The system comprises a fuel cell single unit and an electrochemical hydrogenation device single unit and is characterized in that a water inlet on the electrochemical hydrogenation device single unit is connected with one end of a water inlet pipe; a hydrogen storage material input hole on the electrochemical hydrogenation device single unit is communicated with the bottom of a hydrogen storage material tank by a hydrogen storage material input pipe; a hydrogen storage material hydride outlet on the electrochemical hydrogenation device single unit is communicated with a hydrogen storage material hydride tank by a hydrogen storage material hydride output pipe; a hydrogen storage material outlet on the fuel cell single unit is communicated with the hydrogen storage material tank by a hydrogen storage material output pipe; a hydrogen storage material hydride input hole on the fuel cell single unit is communicated with the hydrogen storage material hydride tank by a hydrogen storage material hydride input pipe; and the hydrogen storage material tank is filled with the hydrogen storage material which is multi-element mixed liquid unsaturated heterocyclic aromatic hydrocarbon. The system not only simplifies the devices (has simple structure) but also greatly improves the safety.

The invention discloses a composite power control system of an impedance self-matching induction heating inverter power supply, and belongs to the technical field of inverter power supply power control. The composite power control system solves the problem of low power supply efficiency because the existing induction heating inverter power supply cannot meet the heating impedance matching requirements of different materials, different coils and different working conditions. The composite power control system of the power supply comprises a power adjusting system and a factor angle control system, wherein the power adjusting system adjusts the power instruction and the fed-back actual power by means of power adjustment, voltage adjustment and current adjustment to obtain a chopping triggersignal; and the power factor angle control system processes an inverter voltage signal and an inverter current signal to obtain an actual power factor angle feedback signal of the system and then generates an inverter control frequency instruction signal, and the inverter control frequency instruction signal is input into a single-phase full-bridge inverter circuit after being subjected to inversion trigger control. The composite power control system is suitable for power control of the inverter power supply.

The invention relates to a direct fuel cell, and in particular relates to a direct fuel cell based on an organic liquid hydrogen storage material. The direct fuel cell comprises a fuel cell single unit, wherein the fuel cell single unit is connected with a load by an AC / DC conversion circuit. The direct fuel cell is characterized in that a hydrogen storage material outlet on the fuel cell single unit is communicated with a hydrogen storage material tank by a hydrogen storage material output pipe; a hydrogen storage material hydride input hole on the fuel cell single unit is communicated with a hydrogen storage material hydride tank by a hydrogen storage material hydride input pipe; a hydrogen storage material hydride pump is arranged on the hydrogen storage material hydride input pipe; a water outlet on the fuel cell single unit is communicated with a water tank by a water outlet pipe; a gas inlet on the fuel cell single unit is communicated with an oxygen inlet pipe; a gas outlet is arranged at the top of the water tank; and the hydrogen storage material tank is filled with the hydrogen storage material which is multi-element mixed liquid unsaturated heterocyclic aromatic hydrocarbon. The direct fuel cell not only simplifies the devices (has simple structure) but also greatly improves the safety.

The present invention relates to a piston type gas turbine engine. It is characterized by that it adopts piston instead of air compressor of traditional gas turbine engine, the crankshaft is connected with piston connecting rod, the piston connecting rod is connected with piston, said piston can be reciprocally moved in the cylinder body, on lower end wall of said cylinder body an air inlet valve is set, the tail end of said cylinder body is equipped with an air supply valve, in the compressed air channel a throttle valve is set, the conical gear on the crankshaft is meshed with the conical gear in the upper end of turbine rotating shaft, and the lower end of said turbine, rotating shaft is connected with turbine.

This invention relates to a wireless sound box wire less connected to audio visual product. Wherein, the audio signal from the audio visual product first passes the audio amplifier circuit and then the PWM circuit; the LED outputs infrared signal; arranging an infrared signal receiving circuit on the said box with back end connected with finite amplifier circuit and power amplifier circuit that drives the horn of the said box by turns. The invention has large power and less distortion and the volume is easy to regulate.

The invention discloses a silicon-based external cavity laser with adjustable wavelength and power and relates to the field of integrated optics of optical communication. The silicon-based external cavity laser is characterized in that the output end of a light source is connected with a first silicon-based optical coupler, the first silicon-based optical couple is connected with a first multimode interferometer, the first multimode interferometer is connected with a first silicon-based microloop filter and a second silicon-based microloop filter, a second multimode interferometer is arranged between the first silicon-based microloop filter and the second silicon-based microloop filter, the second multimode interferometer is provided with two output ends, and one output end is connected with the second silicon-based microloop filter while the other serves the output of the entire silicon-based external cavity laser; the silicon-based external cavity laser further comprises an asymmetric Mach-Zehnder interferometer which is arranged between the first silicon-based microloop filter and the second silicon-based microloop filter; thermal resistance is loaded on the two silicon-based microloop filters and the asymmetric Mach-Zehnder interferometer. By the arrangement, the adjustable wavelength and power is realized, and range of application of the tunable laser is increased.

PURPOSE: A control method of a heater for a drier and an apparatus thereof are provided to control the heater safely by operating the heater in rotating a blower motor over the reference speed, and to improve the reliability by preventing breakage or damage with restricting wrong operation. CONSTITUTION: A heater control apparatus for a drier is composed of a blower forming flow of air circulating in a drum; a heater heating air to supply hot blast to the drum; a speed detecting unit(300) detecting rpm of the blower; a comparator(320) comparing rotational speed from the speed detecting unit with the normal speed of the blower, and outputting a signal for driving the heater; and a control unit controlling the drier and operating the heater by outputting the driving signal. The reliability is improved by operating the heater in applying the heater control signal to the heater driving unit from normal operation of the blower motor.

The invention belongs to the technical field of hydraulic engineering, and particularly relates to a load-sensitive double-hydraulic-cylinder synchronous system and a control method thereof. The synchronous system mainly involves two synchronous drive hydraulic cylinders, a synchronous controller unit and a load sensitive unit, wherein a force instruction of the driven hydraulic cylinder is takenfrom a feedback signal of a force sensor arranged between a driving hydraulic cylinder and the load, and the output force of the driven hydraulic cylinder is adjusted in real time to ensure that the output force of the driven hydraulic cylinder is the same as the output force of the driving hydraulic cylinder so that synchronous driving of the ''driving'' hydraulic cylinder and the ''driven" hydraulic cylinder can be realized; the load sensitive unit ensures that the power supply of the system is matched with the large power demand in the "driving" hydraulic cylinder and the "driven" hydrauliccylinder; and when the "driving" hydraulic cylinder and the "driven" hydraulic cylinder are in an asynchronous working condition, the valve opening pressure difference of a servo valve on the hydraulic cylinder with large power is reduced, the valve opening pressure difference of a servo valve on the hydraulic cylinder with small power is increased, and at the moment, flow output by a pump flowsto the hydraulic cylinder with the small power more. The load-sensitive double-hydraulic-cylinder synchronous system has the advantages that the synchronization speed is fast, the synchronization precision is high, the reliability is high, the energy is saved, and the like.

The invention provides an active power-factor correction circuit device which comprises a segment linear gain circuit, an error amplifier, a pulse width modulation controller and a pulse width modulation signal generator. The segment linear gain circuit is used for receiving feed-forward signals and generating corresponding gain signals, wherein sizes of the gain signals and sizes of the feed-forward signals are correlated in a broken line mode. The error amplifier is used for generating error signals according to output voltage of an alternating-current-to-direct-current converter. The pulse width controller is used for generating control signals according to the gain signals, the error signals, and the output voltage after being rectified of the alternating-current-to-direct-current converter. The pulse width modulation signal generator is used for generating pulse width modulation signals used for controlling a power switch of the alternating-current-to-direct-current converter according to the control signals. As a segment linear gain circuit is utilized to replace a traditional squarer, circuit complexity of an active power-factor correction circuit can be lowered, needed bias voltage sources are reduced, a circuit area is reduced, and electricity power consumption and cost are lowered.

The invention, which relates to the technical field of optical fiber sensing, discloses a long-distance high-capacity quasi-distributed sensing system based on optical fiber random laser. The system comprises a pump laser with adjustable wavelength and broadband, an isolator, a wave combining module, a spectral analysis module, a sensing optical fiber and an FBG (Fiber Bragg Grating) sensor. The long-distance high-capacity quasi-distributed sensing system has the advantages of simple structure, long sensing distance and strong reuse capability. During use, the pump laser is turned on, the output wavelength and the output power of the pump laser are adjusted, and the sensing quantity carried by the sensor at a specific position can be demodulated through the spectral analysis module., The FBG sensors arranged at different positions of the optical fiber can be selected by changing the output wavelength and the output power of the pump; and the change of the external physical quantity isreflected through the wavelength change of the currently selected FBG sensor.

The invention belongs to the technical field of energy conversion, and particularly discloses a hydraulic turbine device. The turbine comprises an inlet device, a guide rail, a connecting rod, a spraypin, rotating wheel blades, an adjusting pin, a rotating wheel hub, a main shaft, a mechanical seal, an inner magnet, a bulb body, guide vanes, an isolation cover, an outer magnet and a volute, wherein the bulb body is arranged in the inlet device, and the spray pin controlled by the connecting rod to move is arranged in the inlet device, so that the flow control is realized; the rotating wheel blades and the rotating wheel hub are connected through the adjusting pin in a chained mode, and the angle of the rotating wheel blades is adjusted through the adjusting pin; and permanent magnetic blocks arranged at intervals are installed on the outer cylindrical surface of the inner magnet, the permanent magnets with opposite magnetic poles are correspondingly installed at the position which arecorresponding to the inner magnets and the inner surface of the outer magnet; and the isolation cover is placed between the inner magnet and the outer magnet, the inner material of the isolation cover is made of metal, and the outer surface of the isolation cover is provided with a plastic separation layer. The turbine device can adapt to working conditions of extremely high water heads, and is suitable for being installed on the downstream of a river channel so as to fully utilize the kinetic energy of the water flow, so that the kinetic energy can be efficiently converted into electric energy.

The invention provides a laser bird-repelling device, and relates to the field of power sector overhead transmission line bird-repelling technologies. The laser bird-repelling device solves the problems that after an existing transmission line bird-repelling device is used for a period of time, birds can adapt to the device, and therefore the bird-repelling effect becomes worse; meanwhile the birds are prone to injury and death due to the existing bird-repelling device. A laser emission unit emits arc laser spots, a light control module controls laser output power through illumination intensity acquired by a photoelectric inductive sensor, a pitching motor is used for driving the laser emission pitching angle of a laser device, an azimuth-drive motor is used for driving the laser device to rotate in the horizontal plane, and the working state of the pitching motor and the working state of the azimuth-drive motor are controlled by an upper computer. The laser bird-repelling device is suitable for repelling the birds on an overhead transmission line.

The invention relates to a double-speed four-power energy-saving three-phase asynchronous motor, the electromagnetic scheme design combines multi-power electromagnetic winding technology and multi-speed motor novel phase interchanging pole changing electromagnetic winding technology to form a novel motor winding 3Y + Y / 3Y connection technical scheme, and by switching by a control cabinet, double-speed and four-power are realized on one motor, thus satisfying special using requirements of different loads and adjusting parameters (changing stroke times) of a well pumping unit. The technology of double-speed and four-power realized on one motor product not only solves the problem that a strong horse pulls a small cart, namely the well pumping unit uses one motor to pump oil, but also changes the stroke times of the well pumping unit. The product is widely suitable for power transmission of a walking beam or belt well pumping unit.

The invention belongs to the field of direct-current distribution system energy storage system control, and particularly relates to a direct-current distribution network virtual inertia control methodbased on a variable droop coefficient. The method comprises the following steps: acquiring a droop coefficient K0 of the flywheel energy storage system in a steady state; obtaining an instantaneous voltage variation delta U through a filter when the voltage fluctuation of the direct-current bus is caused by sudden power change; correcting the variable droop coefficient; restraining a droop coefficient according to upper and lower limits of power output of the flywheel energy storage system; wherein the changed droop coefficient controls the reference power of the flywheel energy storage system in an outer loop controller of the converter, controls a system rotating speed reference value at the same time, and provides a current reference value for an inner loop controller through a PI control link; controlling the output power of the system by the inner loop controller; controlling a droop characteristic curve of the system to swing by utilizing the continuously-changed droop coefficient, and carrying out self-adaptive control so as to continuously reduce the voltage fluctuation of the system; and returning to a stable operation state of the control system.

The invention provides a piezoelectric-modulation vertical cavity semiconductor laser structure comprising a single crystal substrate (1), a buffering layer (2), an n-type DBR reflecting mirror (3), a carrier lower limiting layer (4), a gain region (5), a carrier upper limiting layer (6), a photoelectric limiting layer (7), a p-type DBR reflecting mirror (8), an ohmic electrode contact layer (9), a first transparent electrode (10), two second metal layers (11), an SiO2 antireflection film (12), two SiN insulation layers (13), a second transparent electrode (14), two third metal layers (15) and a first metal layer (16). During powering operation, the cavity of a vertical cavity semiconductor laser deforms to different extents through the piezoelectric characteristics of the SiO2 antireflection film, and the piezoelectric-modulation of the output power of the vertical cavity semiconductor laser can be implemented.

The present invention provides a power unit loss calculation method and a power unit loss calculation device. The power unit loss calculation device comprises a direct-current power source, a pre-charging module, a power unit module, a detection device, a control calculation module and a man-machine interface module; the direct-current side output end positive pole of the direct-current power source is connected with the input end of the pre-charging module; the output end of the pre-charging module is connected with the direct-current side positive pole of the power unit module; the direct-current side output end negative pole of the a direct-current power source is connected with the direct-current side negative pole of the power unit module; the alternating-current output side of the power unit module is connected in parallel with a load resistor; the detection device is used for measuring the voltage and current data of the power unit module and sending the detected data to the control calculation module; the control calculation module is used for sending switching signals to the power unit module; and the power unit module outputs rated power and sends a loss calculation result to a man-machine interface. With the device provided by the invention adopted, the output voltage control and protection function of the power unit module can be realized, and a calculation process is simple.

The invention relates to a direct fuel cell energy storing and supplying system. An integrated direct fuel cell energy storing and supplying system based on a liquid hydrogen storage material is characterized in that an electrochemical hydrogenation device monomer and a fuel cell monomer are integrated, a working medium inlet of the fuel cell monomer is communicated with a first port of a second three-way valve by a first working medium pipe, a second port of the second three-way valve is communicated with the bottom of a hydrogen storage material hydride tank by a second working medium pipe, a third port of the second three-way valve is communicated with the bottom of a hydrogen storage material tank by a sixth working medium pipe, a working medium outlet of the fuel cell monomer is communicated with a first port of a third three-way valve by a fifth working medium pipe, a second port of the third three-way valve is communicated with the hydrogen storage material hydride tank by a fourth working medium pipe, a third port of the third three-way valve is communicated with the hydrogen storage material tank by a third working medium pipe, and the hydrogen storage material tank contains a hydrogen storage material which is multivariate mixed liquid unsaturated heterocyclic aromatic hydrocarbon. According to the integrated direct fuel cell energy storing and supplying system, not only is the device (with a simple structure) simplified, but also the safety is greatly improved.

The invention relates to a direct fuel cell energy storing and supplying system. An integrated direct fuel cell energy storing and supplying system based on a liquid hydrogen storage material is characterized in that an electrochemical hydrogenation device monomer and a fuel cell monomer are integrated, a working medium inlet of the fuel cell monomer is communicated with a first port of a second three-way valve by a first working medium pipe, a second port of the second three-way valve is communicated with the bottom of a hydrogen storage material hydride tank by a second working medium pipe, a third port of the second three-way valve is communicated with the bottom of a hydrogen storage material tank by a sixth working medium pipe, a working medium outlet of the fuel cell monomer is communicated with a first port of a third three-way valve by a fifth working medium pipe, a second port of the third three-way valve is communicated with the hydrogen storage material hydride tank by a fourth working medium pipe, a third port of the third three-way valve is communicated with the hydrogen storage material tank by a third working medium pipe, and the hydrogen storage material tank contains a hydrogen storage material which is multivariate mixed liquid unsaturated heterocyclic aromatic hydrocarbon. According to the integrated direct fuel cell energy storing and supplying system, not only is the device (with a simple structure) simplified, but also the safety is greatly improved.

The invention is an air-distributing mechanism of air-driven automobile engine, mainly including cylinder end, air inlet valve and exhaust valve, where the cylinder end has two parallel-separated columnar holes and air inlet channel and exhaust channel, the air inlet valve and the exhaust valve are set in the two columnar holes, respectively and rotationally cooperate with them, two ends of the air inlet valve are installed with seal washers, respectively, the valve body between the two seal washers has U-cross section to compose the cavity of the air inlet valve, there is an exhaust notch corresponding to the exhaust channel on the exhaust valve, and there is a gear engaging the two valves on one end where the two valves extend out of the columnar hole. It can ensure the maximum pressure occurs at the top stop point in the cylinder, effectively reduce throttling and flowing losses, and largely enhance the economic property of the automobile engine.

The present invention relates to a drier, more particularly a drier and a method of controlling drying for the same for prohibiting a heater form operating with an error and controlling a quantity of a power needed drying. For the process, the present invention is to provide a device ( 320 ) for checking whether a blower ( 31 ) is normally operated or not, a plurality of heaters, and a plurality of switching devices for controlling the heaters.

The invention provides an active cooling ground test system for an aircraft engine, and an assessment method based on the active cooling ground test system. The test system comprises a control system,a measurement system, an oil supply system and an electric heating element with a fuel oil flow channel, wherein the electric heating element is used for simulating a single active cooling channel ofthe aircraft engine; the oil supply system is used for supplying oil to the electric heating element; the control system is used for controlling the electric heating element to be electrified, and storing and collecting test data; the measurement system is used for measuring the temperature of the electric heating element, the temperature of the fuel oil and the like; and in addition, the side wall, which is used for simulating a direction which faces the wall surface of a combustion chamber of the aircraft engine, of the electric heating element adopts non-uniform variable thickness design in a fuel oil flow channel direction. By use of the test system, the along-the-way thermal flux density distribution situation of the cooling channel of the active cooling engine can be more truly simulated, a ground thermal environment with high accuracy is provided for the evaluation and assessment research of the cooling structure of the active cooling engine and heat absorption type fuel, and in addition, the active cooling ground test system is convenient to operate, is low in cost, does not generate additional pollution, and is suitable for engineering application.

The invention provides a power regulation circuit for a load. The power regulation circuit comprises a dynamic frequency adjustment circuit, an electrical level reproduction circuit, a reproduction ratio setting circuit, a sampling comparison circuit and a PWM generator. The dynamic frequency adjustment circuit receives a first clock signal and a variable frequency control signal to generate a second clock signal. The electrical level reproduction circuit generates an electrical level reproduction detection signal according to the second clock signal, wherein the high electrical level of the second clock signal is duplicated to the high electrical level of the electrical level reproduction detection signal. The reproduction ratio setting circuit sets the reproduction ratio of time of duration of reproduction from the high electrical level of the second clock signal to the high electrical level of the electrical level reproduction detection signal according to the frequency modulation current, wherein the reproduction ratio is smaller than 1:1. The sampling comparison circuit compares the electrical level reproduction detection signal and a current sustain signal to generate the variable frequency control signal and feeds back to the dynamic frequency adjustment circuit. The PWM generator generates a PWM signal based on the second clock signal.