41 results about "Electronic oscillation" patented technology

The invention relates to a new-energy lighter. An electronic oscillation circuit, a boosting type DC / DC (direct current) conversion circuit, a lighting circuit and a money detecting circuit are arranged in a casing of the lighter. A switch is arranged on one side of the casing, a lamp and a money detecting lamp are arranged at the bottom of the casing. The direct current carried by the lighter can be used as lighting energy source, high-frequency pulse current can be generated through the oscillation circuit, high-frequency voltage is generated at two ends of a transformer coil, high-voltage discharge sparks can be generated by outputting in an arc discharge manner via a pair of high-voltage discharge needles and can be used for lighting combustible matter in any weather. A power source socket of the lighter is assorted with a universal plug and an adapter, so that the lighter can be used for charging cellphones or digital products in various specifications. Meanwhile, the lighter can be used for lighting and detecting money, and is safe, environment-friendly, energy-saving in use, small in size, convenient to carry, practical and convenient.

The invention relates to an atmosphere suspended particulate matter mass concentration detector based on the national environmental protection HJ618-2011 standard, wherein the atmosphere suspended particulate matter mass concentration detector is suitable for detection of mass concentration of particulate matters from PM2.5 to less than PM 10 in an air environment. In the prior art, PM2.5 fine particles are difficultly interdicted on filtration membranes with the existing quartz, mixed cellulose and other organic filtration membranes; and the oscillation frequency of the existing electronic oscillation balance method is affected by excessive thick dust accumulation, and the filtration membrane weight method has disadvantages of complex operation and difficult calibration accuracy. According to the present invention, based on the aerosol characteristic of the less than PM 10 particulate matters, particularly the PM2.5 fine particulate matters in the ambient air, a suitable microgram scale of a beta-source with a nickel-63 low-energy short-range is selected, the ionization energy absorption principle can be completed provided when the electron is loaded, and the atomic nucleus electron of the dust matter is fixed; and compared with the manual filtration membrane weight method, the method of the present invention can achieve the high accuracy requirement.

The invention relates to a method and device for detecting the material level in a material bin. The device is characterized in that a measuring cable is arranged at the central axis of the circular metal material bin and is parallel with and insulated from the metal bin wall, the measuring cable and the metal bin wall form a parallel plate capacitor, and the capacitance of the parallel plate capacitor is the total capacitance CX of a material bin capacitive sensor; an electronic oscillating circuit is used to form a primary instrument, an RS-485 bus differential drive function is used to transmit a pulse sequence signal between the primary instrument and a secondary instrument, the change of the CX is converted into the corresponding pulse sequence signal and remotely transmitted to the secondary instrument, and the second instrument measures the cycle T of the pulse sequence signal; the material level L1 is obtained. The device is simple in overall structure, easy to implement, fast in detection, high in accuracy, simple to mount, low in cost, convenient for a user to use, free of a mechanical moving device, small in primary instrument size, light, and long in service life.

An electronic oscillator circuit has a first oscillator, for supplying a first oscillation signal, a second oscillator, for supplying a second oscillation signal, a first controller for delivering the first control signal as a function of a phase difference between a first controller input and a second controller input of the first controller; a second controller for delivering the second control signal as a function of a phase difference between a first controller input of the second controller and a second controller input of the second controller; a resonator; at least a second resonance frequency, with a first phase shift dependent on the difference between the frequency of a second exciting signal and the second resonance frequency and processing means, for receiving the first oscillator signal and the second oscillator signal, determining their mutual proportion, looking up a frequency compensation factor in a prestored table and outputting a compensated oscillation signal.

The invention provides a large-power ultrasonic humidifier with lower cost and more suitable for large-scale agricultural humidification. The humidifier comprises an atomization module connected with a power supply and is characterized in that the atomization module includes an ultrasonic oscillation circuit and a plurality of atomizers connected with the ultrasonic oscillation circuit. By adopting the electronic oscillation circuit, the humidifier can transform clean water into fine mist particles through a transducer sheet and generate anions at the same time to improve the environment humidity and refresh the air. The humidifier is also designed to have the functions of automatic water feeding, automatic stop when reaching the water level, water shortage protection, short circuit protection, leakage protection, overheat protection, etc. An intelligent humidity controller is provided to achieve full-automatic humidity control. The atomization transducer sheet can be easily detached, cleaned and replaced. A novel water level sensing switch is provided to automatically switch off the power supply when the water level is less than a value. By adopting the special design, the large-power ultrasonic humidifier can prevent the atomization sheet from being damaged due to operation under water-free condition.

The present invention relates in general to electronic oscillation generators and to the stabilization of electronic oscillation generators, and especially to temperature-compensated oscillator units used in electronics and telecommunications technology, for example, as well as to a method and integrated circuit for temperature compensation of oscillators. The temperature-compensated oscillator unit according to the invention that comprises an integrated circuit (12) and oscillator (10) is characterised in that said oscillator (10) has a known temperature compensation function and the integrated circuit (12) of the oscillator unit comprises a temperature compensation block (14) having at least two local compensation basis functions Phi j ,,j = 0,..., k for selection for at least one oscillator (10) of a specific type, an internal temperature sensor (11) and a data block (13) for calibrating said temperature compensation block (14) in the temperature range to be used, and several differential pairs, with which the temperature compensation of the oscillator (10) is implemented.

The invention relates to a tourmaline anion generator which has enhanced anion release quantity and basically generates no ozone. The tourmaline anion generator comprises a DC (Direct Current) high-voltage unit, a multilayer sphere and an anion transmitting terminal, wherein a DC 12V power source is boosted to 6 KV through the DC high-voltage unit and is connected with the south pole of the multilayer sphere through a high-voltage conductor wire to stimulate the energy of tourmaline crystal and powder in the multilayer sphere, the north pole of the multilayer sphere obtaining 6-8 KV fluctuation voltage is connected with the high-voltage conductor wire of the anion transmitting terminal, and anions are transmitted through a discharge electrode. The DC high-voltage unit comprises a power source input part, an electronic oscillation part, a boosting part and a power distribution part which are installed on a circuit board, and the parts are arranged in a case and are filled with insulating resin. The multilayer sphere comprises the tourmaline crystal arranged in the spherical case, the tourmaline powder tightly wrapping the tourmaline crystal, porous diatomite powder tightly wrapping the tourmaline powder, a metal sheet connected with both ends of the tourmaline crystal and a power source plug connected with the metal sheet. The tourmaline anion generator is used for purifying the air.

The invention relates to a high-efficiency energy-saving cold cathode lamp. A lamp base of a lamp tube of the high-efficiency energy-saving cold cathode lamp is slightly thicker than the lamp tube and is used for installing an electrode, the power consumption can be reduced and the luminous efficiency is improved due to the large electrode. The operating principle of the high-efficiency energy-saving cold cathode lamp is as follows: a lamp core electrode receives outputted current controlled by an electronic oscillation circuit so that electronic powder in the lamp core electrode is activated and ionization induction generates, fluorescent powder is activated under the action of inert gas such as neon so that an energy-saving lamp is continuously lightened, and a purpose of transforming electric energy into light energy is achieved. According to the length and the voltage of the lamp tube, the power of the lamp and the proportion of powder to gas of an activated object, the electronic oscillation circuit is used in a matched way. The high-efficiency energy-saving cold cathode lamp disclosed by the invention utilizes a current induction activation manner so that the service life of the energy-saving lamp is doubled and redoubled, the effective service life of the energy-saving lamp can be more than 20,000 hours, the application range of working voltage is wider, the mercury consumption of the energy-saving lamp is reduced by 95% due to neon activation, and the mercury consumption of the high-efficiency energy-saving cold cathode lamp is below 0.5mg.

The invention discloses a terahertz band elimination filter comprising N * N identical units which are periodically arranged on a plane perpendicular to the incident direction of terahertz waves. No interval exists between the adjacent units, and N is an integer larger than or equal to 2. Each unit comprises a first metal resonance layer, a second metal resonance layer and a substrate; the first metal resonance layer is attached to the center of the upper surface of the substrate, and the second metal resonance layer is attached to the center of the lower surface of the substrate. The first metal resonance layer and the second metal resonance layer are cross-shaped and have the same size. After wave incidence, electromagnetic resonance is generated on the first metal resonance layer and the second metal resonance layer, electromagnetic energy at the resonance frequency is used for maintaining electronic oscillation, so that a filtering stop band is formed. The terahertz band elimination filter has the advantages of being rapid in stop band attenuation, adjustable in bandwidth slightly or in a large range, simple in structure, easy to manufacture, low in cost and the like, and the structure of the terahertz band elimination filter is simplified.

An electronic oscillator circuit has a first oscillator, for supplying a first oscillation signal, a second oscillator, for supplying a second oscillation signal, a first controller for delivering the first control signal as a function of a phase difference between a first controller input and a second controller input of the first controller; a second controller for delivering the second control signal as a function of a phase difference between a first controller input of the second controller and a second controller input of the second controller; a resonator; at least a second resonance frequency, with a first phase shift dependent on the difference between the frequency of a second exciting signal and the second resonance frequency and processing means, for receiving the first oscillator signal and the second oscillator signal, determining their mutual proportion, looking up a frequency compensation factor in a prestored table and outputting a compensated oscillation signal.

The invention discloses a terahertz band-rejection filter comprising N×N identical units, which are periodically arranged on a plane perpendicular to the incident direction of the terahertz wave, and there is no space between adjacent units, N is an integer greater than or equal to 2, and a single The unit includes a first metal resonant layer, a second metal resonant layer, and a substrate; the first metal resonant layer is attached to the center of the upper surface of the substrate, and the second metal resonant layer is attached to the center of the lower surface of the substrate; the first metal resonator Both the first metal resonant layer and the second metal resonant layer are cross-shaped and have the same size; after the wave is incident, electromagnetic resonance is generated on the first metal resonant layer and the second metal resonant layer, and the electromagnetic energy at the resonant frequency is used to maintain electronic oscillation, thus Form the filter stopband. The invention has the advantages of rapid attenuation of the stop band, fine-tuning and wide-range adjustment of the bandwidth, simple structure and easy manufacture, low cost, etc., and simplifies the structure of the terahertz band-stop filter.

The invention discloses a safe automobile remote-control emitter, and belongs to the electronic technical field. The emitter is mainly composed of a two wave four code battery power circuit, a two wave four code button switch circuit, a two wave four code total electronic oscillating circuit switch circuit, a two wave four code one wave / two wave electronic switch circuit, a two wave four code one wave / two wave oscillating circuit switch circuit, a two wave four code one wave one code / one wave two code electronic switch circuit, a two wave four code one wave one code / one wave two code coding electronic circuit, a two wave four code one wave one code / one wave two code encoding output circuit, a two wave four wave two wave three code / two wave four code electronic switch circuit, a two wave four code two wave three code / two wave four code encoding electronic circuit, a two wave four code two wave three code / two wave four code encoding output circuit, a two wave four code one wave two code / two wave two code encoding or gat output circuit, and a two wave four code one wave / two wave two code emission electronic circuit unit. The wave and wave of two waves, the code and code of two codes, and the dual codes and dual codes of four codes can form different combinations, and the safety is high.

The invention relates to a new-energy lighter. An electronic oscillation circuit, a boosting type DC / DC (direct current) conversion circuit, a lighting circuit and a money detecting circuit are arranged in a casing of the lighter. A switch is arranged on one side of the casing, a lamp and a money detecting lamp are arranged at the bottom of the casing. The direct current carried by the lighter can be used as lighting energy source, high-frequency pulse current can be generated through the oscillation circuit, high-frequency voltage is generated at two ends of a transformer coil, high-voltage discharge sparks can be generated by outputting in an arc discharge manner via a pair of high-voltage discharge needles and can be used for lighting combustible matter in any weather. A power source socket of the lighter is assorted with a universal plug and an adapter, so that the lighter can be used for charging cellphones or digital products in various specifications. Meanwhile, the lighter can be used for lighting and detecting money, and is safe, environment-friendly, energy-saving in use, small in size, convenient to carry, practical and convenient.

The invention provides a high-efficiency mercury-free energy-saving bulb consisting of an inner bulb container and an outer bulb container, wherein the outer wall of the inner bulb container and the inner wall of the outer bulb container are provided with one conducting material adhering point, respectively, and each conducting material adhering point is provided with a metal conducting wire to be guided out; a consistent space is kept between the inner bulb container and the outer bulb container, a conducting layer and fluorescent powders are coated on the outer wall of the inner bulb container, and the conducting layer and the fluorescent powders are coated on the interior of the outer bulb container. The operating principle of the high-efficiency mercury-free energy-saving bulb is as follows: the conducting layers receive outputted current controlled by an electronic oscillation circuit to generate ionization induction, and the fluorescent powders are activated under the action of inert gas such as neon to continuously lighten a bulb body, so that a purpose of transforming electric energy into light energy is achieved. The high-efficiency mercury-free energy-saving bulb utilizes a current induction activation manner so as to avoid a process of heating a filament of the traditional energy-saving lamp and prolong the effective service life to be more than 20,000 hours; and the high-efficiency mercury-free energy-saving bulb prolongs the service life and reduces the mercury pollution although the bulb has a more complex process compared with the traditional energy-saving lamp.

A crystal oscillator and a startup method for initiating operation of a crystal oscillator, the crystal oscillator includes an oscillator structure including a crystal resonator and an electronic oscillator circuit connected to the crystal resonator, the oscillator structure having a first terminal and a second terminal, a startup controller operable to initiate an oscillation in the oscillator structure by exciting the oscillator structure with a sequence of excitation signals derivable from a clock signal and when triggered by a timing signal, the sequence of excitation signals includes at least a first excitation signal and a second excitation signal, a comparator including a first and a second input terminal and an output terminal, the first input terminal being connected to the first terminal and wherein the second input terminal is connected to the second terminal.

The invention relates to an enhanced vehicle remote control emission mode, and belongs to the technical field of electrons. The enhanced vehicle remote control emission mode comprises a three-carrier-wave three-code battery power supply, a three-carrier-wave three-code button switch, a three-carrier-wave three-code total electron oscillation circuit switch, a three-carrier-wave three-code one-carrier-wave three-code electron switch, a three-carrier-wave three-code one-carrier-wave three-code coding electron circuit, a three-carrier-wave three-code one-carrier-wave three-code coding amplification excitation circuit, a three-carrier-wave three-code one-carrier-wave three-code emission electron circuit, a three-carrier-wave three-code two-carrier-wave electron switch, a three-carrier-wave three-code two-carrier-wave oscillation circuit switch, a three-carrier-wave three-code two-carrier-wave two-code electron switch, a three-carrier-wave three-code two-carrier-wave two-code coding electron circuit, a three-carrier-wave three-code two-carrier-wave two-code coding amplification excitation circuit, a three-carrier-wave three-code two-carrier-wave two-code emission electron circuit, a three-carrier-wave three-code three-carrier-wave one-code electron switch, a three-carrier-wave three-code three-carrier-wave one-code coding electron circuit, a three-carrier-wave three-code three-carrier-wave one-code coding amplification excitation circuit, and a three-carrier-wave three-code three-carrier-wave one-code emission electron circuit. According to the present invention, by using the three-carrier-wave three-code, the carrier wave and the code can be flexibly selected and matched, such that the safety is high, and the production installation is easy.

An electronic oscillation signal generation circuit includes an electronic oscillation circuit, a DC voltage source for providing a DC voltage to the electronic oscillation circuit, a switch for electrically connecting the electronic oscillation circuit to ground when the switch is turned on so as to generate an analog oscillation signal after the switch is turned off, a conversion circuit for converting the analog oscillation signal to a digital oscillation signal, a counter for generating a control signal when the digital oscillation signal reaches a predetermined number of periods, a delay unit for generating a delay signal a predetermined time after a falling edge of the digital oscillation signal is triggered, and a pulse signal generation circuit electrically connected to the counter and the delay unit for generating a pulse signal according to the control signal and the delay signal so as to turn on the switch.

The invention discloses a PMI foam loop radome, and aims to provide an antenna which is high in transmission efficiency, small in transmission loss, light in weight and good in damping performance andhas a filtering function. The method is realized through the following technical scheme: the appearance of the annular radome is a cylinder with chamfers, a cavity used for containing antenna units is formed in the cylinder, passive resonance units are embedded into the cylinder wall to form a frequency selection surface of a periodic array structure, a spatial filter is formed, and the filter surrounds the annular cylinder wall to form a flexible microstrip filter network; when incident electromagnetic waves pass through the filter network, acting force generated by the electric field on electrons enables the electrons to oscillate, so that an induction current is formed at the metal surface of the filter network, part of the energy of incident electromagnetic waves is converted into kinetic energy for maintaining an electronic oscillation state, and the other part of energy passes through the frequency selection surface to be transmitted to the antenna unit. The PMI foam loop radomecarries the filter network to selectively filter the electromagnetic waves of the non-antenna working frequency bands.

The invention provides an automobile main-wave multi-code secondary-wave single-code remote control emitter, and belongs to the technical field of electronic engineering. The emitter consists of a main-wave multi-code secondary-wave single-code battery supply, a main-wave multi-code secondary-wave single-code button switch, a main-wave multi-code secondary-wave single-code master electron oscillating circuit switch, a main-wave multi-code main-wave electronic switch, a main-wave multi-code main-wave oscillating circuit switch, a main-wave multi-code main-wave one-code electronic switch, a main-wave multi-code main-wave two-code electronic switch, a main-wave multi-code main-wave three-code electronic switch, a main-wave multi-code main-wave one-code coded electronic circuit, a main-wave multi-code main-wave two-code coded electronic circuit, a main-wave multi-code main-wave three-code coded electronic circuit, a main-wave multi-code main-wave one-code coded output electronic circuit, a main-wave multi-code main-wave two-code coded output electronic circuit, a main-wave multi-code main-wave three-code coded output electronic circuit, a main-wave multi-code or gate output circuit, a main-wave multi-code transmitter circuit unit, a main-wave multi-code secondary-wave single-code main-wave electronic switch, a main-wave multi-code secondary-wave single-code secondary-wave electronic switch, a main-wave multi-code secondary-wave single-code main-wave oscillating circuit switch, a main-wave multi-code secondary-wave single-code secondary-wave oscillating circuit switch, a secondary-wave single-code secondary-wave four-code electronic switch, a secondary-wave single-code secondary-wave four-code coded electronic switch, a secondary-wave single-code secondary-wave four-code coded output electronic circuit, and a secondary-wave four-code secondary-wave single-code transmitter circuit. The safety of the emitter is improved by adopting changes of a plurality of forms of strong-wave multiple codes and weak-wave single codes.

A single-wave dual-code emission designing scheme belongs to the technical field of electronics and comprises a single-wave dual-code emission designing scheme I and a single-wave dual-code emission designing scheme II. The single-wave dual-code emission designing scheme mainly includes single-wave dual-code power supply resources, a single-wave dual-code button switch, a single-wave dual-code oscillating circuit, a single-wave first-code electronic switch, a single-wave first-code encoding electronic circuit, a single-wave first-code output electronic circuit or a single-wave first-code emission isolation electronic circuit, a single-wave second-code electronic switch, a single-wave second-code encoding electronic circuit, a single-wave second-code output electronic circuit or a single-wave second-code emission isolation electronic circuit, a single-wave dual-code emission electronic circuit or a single-wave first-code emission electronic circuit, and a single-wave dual-code emission electronic circuit. A single-wave dual-code manner is adopted, even through it's a single wave, the carrier wave of the single wave can be flexibly selected between the first carrier wave and the second carrier wave, and the encoding of the two carrier waves is different. The single-wave dual-code emission designing scheme can match a central locking automatic input device for use after all the vehicles doors are closed, so that the automobile security coefficient is effectively increased.

The invention provides a design scheme of three-code double-wave emission, and belongs to the technical field of electronic engineering. The design scheme mainly comprises a three-code double-wave battery supply, a three-code double-wave button switch, a three-code double-wave electronic oscillating circuit switch, a three-code double-wave one-wave electronic switch, a three-code double-wave one-wave oscillating circuit switch, a three-code double-wave one-wave one-code electronic switch, a three-code double-wave one-wave two-code electronic switch, a three-code double-wave one-wave one-coded electronic switch, a three-code double-wave one-wave two-coded electronic switch, a three-code double-wave one-wave double-code or gate output circuit, a three-code double-wave one-wave double-code emission electronic circuit, a three-code double-wave two-wave electronic switch, a three-code double-wave two-wave three-coded electronic circuit, and a three-code double-wave two-wave three-code emission electronic circuit. Two types of different carriers and three types of different coded signals can be used alternately during emission to realize remote control emission of a control target to the outside, a central lock is automatically locked after all car doors are closed, and an alarm system is automatically put into use by matching with a device, so that the design scheme is convenient and has a strong modern sense. The safety factor of an automobile is effectively improved.

The invention relates to a dual-wave and dual-code remote control emitter and belongs to the technical field of electrons. The dual-wave and dual-code remote control emitter mainly comprises a dual-wave and dual-code battery power supply, a dual-wave and dual-code button switch, a dual-wave and dual-code electronic oscillation circuit switch, a dual-wave and dual-code first-wave electronic switch, a dual-wave and dual-code first-wave coding insulation electronic circuit, a dual-wave and dual-code first-wave coding electronic circuit, a dual-wave and dual-code first-wave emitting insulation electronic circuit, a dual-wave and dual-code first-wave emitting electronic circuit or unit, a dual-wave and dual-code second-wave electronic switch, a dual-wave and dual-code second-wave coding insulation electronic circuit, a dual-wave and dual-code second-wave coding electronic circuit, a dual-wave and dual-code second-wave emitting insulation electronic circuit and a dual-wave and dual-code second-wave emitting electronic circuit or unit, wherein two waves of the emitter can be radio wave and infrared wave, or infrared wave and ultrasonic wave or ultrasonic wave and radio wave; two codes of the emitters can be fixed code and fixed code, or fixed code and roll code or roll code and roll code. The dual-wave and dual-code remote control emitter is high in confidentiality, stable and reliable in property and simple and easy to produce and mount.

A high voltage transformer (Tr) includes a primary winding (Lp), secondary windings (Ls1, Ls2, Ls3), and diodes (Di) coupled between successive secondary windings. The polarity of the diodes and the secondary windings is selected such that the flyback voltages across each of the secondary windings are summed via conductive diodes during at least a part of a flyback period (Tf) for generating a high voltage. A damp-circuit (1) comprises a rectifier element, a load (L), and a further winding (Ls4) of the high voltage transformer. These elements are arranged with respect to one of the secondary windings such that the further winding and the one of the secondary windings form a capacitance (Cd) across the load. The diode (D) is non-conductive during the flyback period. In this way, electrical oscillations of the high voltage transformer are damped.

The invention relates to a balanced type maintenance appliance (figure 4) for prolonging the service lives of storage batteries. The maintenance appliance comprises an electronic oscillation circuit (figure 3) and a balanced type amplification circuit (figure 1), and has the functions of prolonging the service lives and maintaining for lead acid storage batteries and lead crystal storage batteries.

The invention discloses constant temperature electronic oscillation equipment which comprises an upper layer printed circuit board, a lower layer printed circuit board, a bottom plate, a resonance crystal and a shell. The lower layer printed circuit board is electrically and supported with the upper layer printed circuit board through a lead, the bottom plate is electrically and supported with the lower layer printed circuit board through a lead, the resonance crystal is clamped between the upper layer printed circuit board and the lower layer printed circuit board, the shell is used for containing the upper layer printed circuit board, the lower layer printed circuit board and the resonance crystal in a sealing way, and a locating groove used for containing and locating the resonance crystal is arranged in at least one of the upper layer printed circuit board and the lower layer printed circuit board. Compared with the prior art, the invention has the advantages of reliable location and easy change of the resonance crystal because the locating groove used for containing and locating the resonance crystal is arranged in at least one of the upper layer printed circuit board and the lower layer printed circuit board.

A communication device for a motor vehicle having a near field communication device, the communication device includes an antenna portion, a drive circuit, and a matching circuit and a filter circuit provided between the drive circuit and the antenna coil. The antenna part forms an electrical tank circuit having a first resonance frequency. The matching circuit and the filter circuit form at least one second oscillating circuit with the second resonant frequency, and the first oscillating circuit is coupled with the second oscillating circuit according to the critical coupling method.

The invention provides a large-power ultrasonic humidifier with lower cost and more suitable for large-scale agricultural humidification. The humidifier comprises an atomization module connected witha power supply and is characterized in that the atomization module includes an ultrasonic oscillation circuit and a plurality of atomizers connected with the ultrasonic oscillation circuit. By adopting the electronic oscillation circuit, the humidifier can transform clean water into fine mist particles through a transducer sheet and generate anions at the same time to improve the environment humidity and refresh the air. The humidifier is also designed to have the functions of automatic water feeding, automatic stop when reaching the water level, water shortage protection, short circuit protection, leakage protection, overheat protection, etc. An intelligent humidity controller is provided to achieve full-automatic humidity control. The atomization transducer sheet can be easily detached,cleaned and replaced. A novel water level sensing switch is provided to automatically switch off the power supply when the water level is less than a value. By adopting the special design, the large-power ultrasonic humidifier can prevent the atomization sheet from being damaged due to operation under water-free condition.