An apparatus for treating a flow of fluid with microwave radiation, the apparatus comprising: a vessel having a sidewall and opposed first and second end walls defining a substantially cylindrical chamber, the first end wall being disposed a predetermined distance d1 from the second end wall; a pipeline for flowing fluid through, the pipeline passing through the first end wall towards the second end wall of the vessel, the chamber and the pipeline being substantially co-axial and the pipeline being substantially transparent to microwave radiation; and a microwave radiation inlet in the side wall of the vessel for admitting microwave radiation of wavelength λ into the chamber, wherein the distance d1 is substantially equal to an integral multiple of λ/2 so that the chamber is a microwave resonator.

A method of treatment of water in an aquatic environment. Water is first pumped from a reservoir to a first mixing station. An inert gas is introduced into the pumped water at the first mixing station to provide inert gas saturated water, which inert gas saturated water will displace undesired gasses in the water in the reservoir. The inert gas saturated water is then pumped to a sparging column such that the inert gas and undesired gasses will be released from the inert gas saturated water to provide depleted water.

The separation of single-walled carbon nanotubes (SWNTs), by electronic type using centrifugation of compositions of SWNTs and surface active block copolymers in density gradient media.

In an embodiment, a fuel decontamination unit comprises a decontamination region containing fuel; and an ultraviolet light located in the decontamination region; wherein the ultraviolet light is configured to irradiate the fuel. In an embodiment, a method of decontaminating fuel comprises flowing a contaminated fuel into a decontamination unit; irradiating the fuel with ultraviolet radiation that is emitted from the ultraviolet light such that the contaminated fuel becomes a purified fuel; flowing the purified fuel out of the decontamination unit; wherein a microorganism level in the purified fuel is less than that of the contaminated fuel.

The present invention is a method and material for using a sorbent material to capture and stabilize mercury. The method for using sorbent material to capture and stabilize mercury contains the following steps. First, the sorbent material is provided. The sorbent material, in one embodiment, is nano-particles. In a preferred embodiment, the nano-particles are unstabilized nano-Se. Next, the sorbent material is exposed to mercury in an environment. As a result, the sorbent material captures and stabilizes mercury from the environment. In the preferred embodiment, the environment is an indoor space in which a fluorescent has broken.

A patient wearable, continuously operating extracorporeal pump apparatus which accesses the patient's arterial venous pressure differential by applying external pressure to a subcutaneous graft that has been cannualized to modulate blood flow through an extracorporeal circuit and to drive the pump for delivering a medicament, such as an anticoagulant, to the site of an intravenous cannula to prevent clogging thereof and also to move a dialysate through a circuit, including a dialyzer and a dialysate rejuvenating cartridge, whereby kidney failure can be treated without recourse to prior art hemodialysis machines found in most treatment facilities. With slight modification, the present invention can be used to remove excess fluids from CHF patients, to remove toxins from the blood in those suffering from liver failure and to facilitate administration of insulin to diabetics and/or glucose to those having hypoglycemia.

Different components of natural oils are separated by forming solid complexes of components of the natural oil with a solvent, and then separating the solid complexes from the remaining liquids. The natural oil is cooled in the presence of a solvent, and at least one component of the oil forms the solid complex with the solvent. This solid complex is separated from the remaining liquid portion of the oil solution, which also contains the solvent. Additional options concentration steps can further concentrate the components left in the liquid phase.

Separation processes using osmotically driven membrane systems are disclosed generally involving the extraction of solvent from a first solution to concentrate solute by using a second concentrated solution to draw the solvent from the first solution across a semi-permeable membrane. Enhanced efficiency may result from using low grade waste heat from industrial or commercial sources. Pre-treatment and post-treatment may also enhance the osmotically driven membrane processes.

A magnetic water conditioner treats water with a magnetic field. The magnetic water conditioner includes a tank having an inlet operable to receive water from a pump and an outlet operable to discharge the water. The magnetic water conditioner is installed in close proximity to the pump. A plurality of permanent magnet members are aligned and spaced apart in the interior of the tank with north and south poles disposed at opposite sides of the permanent magnet members. The water flows through the gaps between the permanent magnet members, thus being subjected to magnetic fields created by the permanent magnet members.

Systems for treating biomass for the production of ethanol are disclosed. The systems are configured to treat a liquid component separated from biomass to yield sugars available to be fermented into a fermentation product. The systems comprise a filter configured to remove particulate matter to provide a filtered component and an apparatus configured to remove inhibitors from the filtered liquid component provide a treated liquid component comprising sugars available for fermentation. Methods for treating for treating biomass useful in the production of a fermentation product are also disclosed. The methods include the steps of filtering a liquid component to remove particulate matter thereby yielding a filtered liquid component, and treating the filtered liquid component to remove inhibitors thereby yielding a treated liquid component comprising sugars available to be fermented into a fermentation product.

One embodiment of the present invention relates to a method for inflating a chamber within an inflatable avalanche safety system. The method includes providing an inflatable avalanche safety system including an inflatable chamber; receiving a user-triggered action intended to activate the avalanche safety system; transmitting ambient air from an external region to within the inflatable chamber; and inflating the inflatable chamber entirely with the transmitted external ambient air to a particular internal pressure and shape configured to protect the user from burial during an avalanche. The transmission of ambient air within the inflatable chamber may be accomplished with a fan or an electrical component.

A lid lock controller includes a lid lock unit operable in a lock state, which keeps the lid closed, and an unlock state, which allows for the lid to open. A detection unit detects an unlocking operation performed on the lid lock unit. A key check unit checks whether or not an electronic key is located in the vicinity of the vehicle through wireless communication between the vehicle and the electronic key when the unlock operation is detected. An unlocking unit switches the lid lock unit to the unlock state when the electronic key is located in the vicinity of the vehicle. The unlocking unit switches the lid lock unit to the unlock state even when the electronic key is not located in the vicinity of the vehicle as long as a further lid unlock condition is satisfied.

An apparatus and method are provided for filling multi-chamber containers with different loose bulk materials. The apparatus and method may be particularly well-suited to packaging at least one bulk material, which is susceptible to water, chemicals, or other contaminants, with at least one other bulk material. The apparatus is a machine that includes separate hoppers for handling the separate bulk materials, and directs the separate bulk materials into different chambers of a multi-chamber container, which is then transported away from the machine for storage or use. The machine may include one or more movable hoppers supported on tracks, for moving the bulk materials to the hoppers that direct the bulk materials into different chambers of the multi-chamber container. A controller and data logger may be provided to control the apparatus and record the quantity and/or weight of the contents of each multi-chamber container.

A system for filling a jar with powdery material, for example for the manufacture of nuclear fuel, including a device for connection between the jar and a material feed system, where the device includes: a stationary connection portion connected to the feed system,a connection portion which moves relative to the stationary connection portion intended to be connected to the container's filling orifice, where the moving connection portion includes in the area of a downstream end a lip seal to achieve a tight connection by contact with the contours of the jar's filling orifice and where the said downstream end is connected to the stationary connection portion by a bellows so as to provide mechanical disengagement between the downstream end of the moving connection portion and the stationary connection portion.

Method for filling containers with liquids, wherein the containers are filled using a plurality of controllable filling elements and the liquid is fed to these filling elements starting from a reservoir, common to the filling elements, for storing the liquid, wherein during the filling the containers are transported at least in sections along a circular track and wherein the filling of the containers by at least one filling element is controlled as a function of at least one first parameter characteristic of the liquid in the reservoir and this parameter is determined repeatedly at given intervals of time during the filling operation.

A container (1, 2) for storing and dispensing a liquid, the container including an access port (16) having a frangible seal (18) for allowing contained liquid to be dispensed. A vent (19) permeable to vapour but impermeable to liquid is also provided so that vapour may be vented from the interior of the container.

A refrigerator includes a refrigerator cabinet and a refrigerating compartment within the refrigerator cabinet. A beverage dispensing system is operatively connected to the refrigerator cabinet, the beverage dispensing system configured to dispense a stream of a beverage. The beverage dispensing system includes a light source and a light sensor positioned on opposite sides of the stream of the beverage. The beverage dispensing system is configured for detecting if dispensement of the beverage is occurring and characterizing the volume or amount of the beverage being dispensed.

Devices and methods for clamping a beverage extraction device to a beverage container, such as a wine bottle. One or more clamp arms may be arranged to clamp the extraction device to a wine bottle as well as allow the device to be supported upright on a table top. Clamp arms may include tab and ridge features that operate to properly engage and position a wide variety of different bottle neck shapes relative to the device. The one or more clamp arms may move the bottle neck distally, e.g., toward a resilient pad, so that the neck is suitably positioned relative to the device. Proper positioning and engagement of the neck may allow for desired piercing of a cork or other closure of the bottle by the device.

A method to prevent gelation of an uncured gelcoat composition during storage is described. The method includes applying a gelation inhibitor to the surface of a gelcoat composition in the container to prevent premature gelation. The gelation inhibitor additionally prevents the formation of a crust on the inner surface of storage container lids.

An apparatus for safety-compliant emptying and filling of a reagent container (24, 40) for a tissue processor (20) comprises a suction line (30, 42) for aspirating a reagent out of the reagent container (24, 40) and a delivery line (32, 44) for filling the reagent container (24, 40) with the reagent, a terminating opening (31, 43) of the suction line (30, 42) being spaced away from a terminating opening (33, 45) of the delivery line (32, 44).

A reusable aseptic connector is provided. The connector may be used to provide fluid communication between a bag-in-box (BIB) container and a beverage dispenser. The connector may provide aseptic properties of the connection by insulation of an inner volume of a first part and an inner volume of a second part, with the beverage component kept from contacting any of the part of the connector structure that are exposed to the environment and have a risk of induced contamination. The connector may comprise a resilient membrane and a sliding tube wherein the sliding tube is configured to have a portion move toward and through the resilient membrane to establish fluid communication between the first part and the second part, and for the portion to move away from the resilient membrane to destablish fluid communication between the first part and the second part when desired.

A container and method are provided for storing fat containing liquid products. The container includes a body defining a storage chamber for receiving the product, and a container closure. A first material portion forms at least most of the surface area overlying the storage chamber that can contact any product therein. Neither the body nor the first material portion leach more than a predetermined amount of leachables into the product or undesirably alter a taste profile thereof. A needle penetrable and thermally resealable second material portion either (i) overlies the first material portion and cannot contact any product within the storage chamber, or (ii) forms a substantially lesser surface area overlying the storage chamber that can contact any product therein in comparison to the first material portion. A sealing portion is engageable with the body to form a substantially dry hermetic seal between the container closure and body.

A communication device or auxiliary ECU is activated when a fuel door of a fuel cell vehicle is open. Upon closing the fuel door, the communication device/ECU is shut off. The communication device/auxiliary ECU is operational regardless of whether the keys in the vehicle or not. This assures that communication of information can occur when a refueling station is most likely to request the information, i.e. when the fuel door is open. A temperature measurement device may monitor a vehicle tank temperature, communicate the tank temperature data to a filling station, and confirm that the tank temperature data is associated with the tank being filled.

High-altitude balloons and apparatuses for filling such high-altitude balloons are provided. As an example, an apparatus for filling a high-altitude balloon includes a tube extending through envelope material of the balloon is provided. The apparatus also includes a flange connected to a first end of the tube. The flange is connected to an interior surface of the balloon. A fitting is connected to a second end of the tube. The fitting is configured for attachment with an apparatus for filling the balloon with lift gas. In addition, methods of filing high-altitude balloons with lift gas and methods of manufacturing balloons are also provided.

An apparatus to introduce a defined amount of a second powder into a process container in which a first powder or a powder mixture is present, includes a coupling flange having a cover flap located on the process container. The second powder is introduced into a tubular cartridge mounted displaceably in a transport unit, the latter including a joining flange having a cover flap. The joining flange is joinable to the coupling flange so that the respective cover flaps can be opened, and the cartridge can be pushed through openings thereby provided into the plane of the inner wall of the process container. The second powder is emptied from the cartridge into the process container by a delivery piston. The cartridge may include a piston rod having multiple pistons. Other embodiments include a double piston, a rotatable cartridge core or a rotary closure.

A lid lock controller includes a lid lock unit operable in a lock state, which keeps the lid closed, and an unlock state, which allows for the lid to open. A detection unit detects an unlocking operation performed on the lid lock unit. A key check unit checks whether or not an electronic key is located in the vicinity of the vehicle through wireless communication between the vehicle and the electronic key when the unlock operation is detected. An unlocking unit switches the lid lock unit to the unlock state when the electronic key is located in the vicinity of the vehicle. The unlocking unit switches the lid lock unit to the unlock state even when the electronic key is not located in the vicinity of the vehicle as long as a further lid unlock condition is satisfied.

A pressure-stable cylinder/piston unit which blocks water vapor and oxygen and is designed for a needle-free injector, with a chamber arranged in a cylinder, which blocks water vapor and oxygen, and designed for long-term and sterile storage of an injection solution, an end wall with at least one nozzle bore or one outlet element, a pressure-stable outer cylinder, and a pressure-stable piston arranged movably in the chamber and blocking water vapor and oxygen. Methods for bubble-free, automatic or manual filling of the cylinder/piston unit, also at atmospheric pressure are also disclosed.

A conveying device for free-flowing fine-particle solids, in particular for powdery and/or granular (mixed) material, especially plastic granulate, includes a vertically arranged and flexibly mountable telescopic pipe for the conveyance of, preferably, polymer granulates, for example in a plant for the filling of polymer granulates.

The phase margin compensation method according to an exemplary embodiment of the present invention includes: outputting reference voltage (Vout2); outputting a first reference voltage (Vout1) actually supplied to the target circuit; comparing the reference voltage (Vout2) with the first reference voltage (Vout1) by the comparator; counting any section of an output signal (pulse signal) from the comparator by a predetermined frequency by the duty cycle calculator; and controlling a phase margin of a frequency of output voltage supplied to the target circuit by controlling buffer current based on the duty cycle ratios and the output bit information fed back from the duty cycle calculator.

A DC-DC converter includes a first amplifier that amplifies a first difference between a first reference voltage and a feedback voltage corresponding to an output voltage, a second amplifier that amplifies a second difference between the first reference voltage and an integrated value of the feedback voltage, and a controller that controls a switching circuit to change the output voltage when the first difference reaches the second different.

A method of operating a switching power converter may include determining an average value of a measured parameter for substantially each switching cycle, and adjusting a control parameter during substantially each switching cycle in response to a corresponding one of the average values. In one embodiment, the control parameter comprises a switch duty cycle, and the measured parameter comprises an output current. Determining the average value of the measured parameter may include obtaining a first sample of the measured parameter during a switching cycle, and calculating the average value of the measured parameter during the switching cycle in response to the first sample.

A power supply for a load control device generates a DC voltage and provides an asymmetrical output current, while drawing a substantially symmetrical input current. The power supply comprises a controllably conductive switching circuit for controllably charging an energy storage capacitor across which the DC voltage is produced. The energy storage capacitor begins charging at the beginning of a half-cycle and stops charging after a charging time in response to the magnitude of the DC voltage and the amount of time that the energy storage capacitor has been charging during the present half-cycle. The charging time is maintained substantially constant from one half-cycle to the next. The power supply is particularly beneficial for preventing asymmetrical current from flowing in a multiple location load control system having a master load control device supplying power to a plurality of remote load control devices all located on either the line-side or the load-side of the system.

Efficiency of a switch mode power supply (SMPS) is optimized by operating the SMPS in an asynchronous mode when current being supplied therefrom is less than a certain current value and operating the SMPS in a synchronous mode when the current being supplied therefrom is equal to or greater than the certain current value. When the SMPS is operating in the synchronous mode high-side and low-side power transistors alternately turn on and off. When the SMPS is operating in the asynchronous mode only the high-side power transistor turns on and off and the low-side power transistor remains off. When charging a battery with the SMPS discharge of the battery is eliminated when operating in the asynchronous mode at a low current output.

A power conversion system has a power converter configured to receive an input voltage signal, convert the input voltage to an output voltage signal, and provide the output voltage signal to a load and a closed loop compensator configured to receive the output voltage signal and a reference voltage signal, the closed loop compensator configured to transmit an error signal indicative of a difference between the output voltage signal and the reference voltage signal. The power conversion system further has a pulse with modulator configured to receive the error signal and modulate a control signal with the error signal to control the output voltage signal, the pulse width modulator configured to transmit the control signal to the power converter and logic configured to receive the error signal and control the closed loop compensator based upon the error signal. A controller observes the error signal characterstics such as peak-to-peak values, frequency and phase and adjust the closed loop controller variables and other power converter system variables in order to improve the dynamic performance and improve stability.

A DC/DC converter arrangement includes an input terminal to receive a supply voltage, an output terminal to provide an output voltage and a switching arrangement, including a coil and at least two switches to provide a Buck-Boost conversion. The arrangement further includes a current detection circuit which is coupled to the switching arrangement for sensing a coil current and a comparator, including a first input which is coupled to the output terminal and a second input which is coupled to an output of the current detection circuit. An output of the comparator is coupled to the switching arrangement. Furthermore, the arrangement includes a ramp generator which is coupled to the first or the second input of the comparator.

The present disclosure is directed to a voltage-to-current sensing circuit having a bias terminal configured to receive a reference voltage, an offset terminal configured to receive an offset current, and an operational amplifier configured to output a low voltage signal. The device includes a first amplifier having first and second high voltage inputs configured to receive a first voltage difference across a sense component on a high voltage line and to generate a first current, a second amplifier having first and second low voltage inputs configured to receive a second voltage difference between the bias terminal and the offset terminal and to generate a second current, a summing circuit configured to provide an intermediate voltage corresponding to a sum of the first and the second currents, and a low-voltage transistor coupled to an output of the amplifier and controlled by the intermediate voltage to generate the output current.

A controller used in a buck-boost converter includes a clock generator, an error amplifying circuit, a comparing circuit, a proportional sampling circuit, a logic circuit, a pulse width increasing circuit, first and second driving circuits. Based on a clock signal generated by the clock generator, the proportional sampling circuit samples the difference between a current sensing signal and a compensation signal generated by the error amplifying circuit, and generates a proportional sampling signal. The pulse width increasing circuit generates a sum control signal based on the proportional sampling signal and a logic control signal generated by the logic circuit, wherein a modulation value adjusted by the proportional sampling signal is added to the pulse width of the logic control signal to generate the pulse width of the sum control signal. The first and second driving circuits generate driving signals based on the sum control signal and the logic control signal.

A method for controlling voltage crossing a power switch of a switched-mode power converter includes the steps of: controlling a switch frequency of the power switch of the switched-mode power converter to a first frequency as activating the switched-mode power converter; and then changing the switch frequency of the power switch to a second frequency after the switched-mode power converter is activated for a predetermined time; wherein the first frequency is lower than the second frequency.

In some aspects of the invention, overcurrent protection is carried out by suppressing fluctuations in current flowing through a switching element after overcurrent detection. A peak current reaching time detection circuit detects a peak current reaching time needed until current flowing through a switching element reaches a peak value. A difference voltage detection circuit, including a ½ time detection circuit which detects a time of ½ an ON time of the preceding cycle of the switching element, detects difference voltage between reference voltage used when detecting overcurrent flowing to a load and a signal which has detected current flowing through the switching element for the ½ time. A delay time adjustment circuit, based on at least one of the peak current reaching time and difference voltage, carries out adjustment and control of a delay time occurring until the time when the switching element is turned off after detecting the overcurrent.

Methods and systems are described for providing power factor correction for high-power loads using two interleaved power factor correction stages. Each power factor correction stage includes a controllable switch that is operated to control the phasing of each power factor correction stage. The phasing of output current from the second power factor correction stage is shifted 180 degree relative to the output current from the first power factor correction stage.

In accordance with one embodiment of the present disclosure, a multi-phase voltage regulator may comprise a plurality of phases, each phase configured to supply electrical current to one or more information handling resources electrically coupled to the voltage regulator. A controller may be electrically coupled to the plurality of phases. The controller may designate at least one of the plurality of phases as a first state phase, and designate each of the plurality of phases not designated as a first state phase as a second state phase. The controller may alternate the designation of at least two of the plurality of phases between a first state phase and a second state phase. Each first state phase may be configured to supply a first electrical current regardless of electrical current demand. Each second state phase may be configured to supply a second electrical current based on the current demand.

In one implementation, a modular power converter having a reduced switching loss includes a package, a field-effect transistor (FET) including a gate terminal, a drain terminal, and a source terminal, and fabricated on a semiconductor die situated inside the package, and a driver circuit inside the package. The driver circuit is configured to drive the gate terminal of the FET. The driver circuit is further configured to sample a drain-to-source voltage (VDS) of the FET directly from the drain terminal and the source terminal, thereby enabling the reduced switching loss.

The invention relates to a system for eliminating current surges that includes a first voltage regulator (7) having a current limit programmable to a value (I(limit)) that depends on the value of the intermittent current surges (IO(surge)) required by the intermittent load (3) and the relationship thereof to the work cycle, a second voltage regulator (9), a condenser (4) connected between the first and second regulators (7, 9), that loads when the current is no longer required and that unloads when there is a need for output current to provide current to the second regulator (9) which absorbs the changes in voltage produced by the loading/unloading of the condenser and provides a constant voltage for any value of the required output current surge, independently of voltage changes in the condenser (4), and a control loop between a sensor for the output current provided to the load and an input limit (15) for the input current (II) in the first regulator (7). Thus, the input current (I(limit)) (1) and the output voltage (VLoad) are constant for any value of the output current surge (IO(surge)).

A “windowless” H-bridge buck-boost switching converter includes a regulation circuit with an error amplifier which produces a ‘comp’ signal, a comparison circuit which compares ‘comp’ with a ‘ramp’ signal, and logic circuitry which receives the comparison circuit output and a mode control signal indicating whether the converter is to operate in buck mode or boost mode and operates the primary or secondary switching elements to produce the desired output voltage in buck or boost mode, respectively. A ‘ramp’ signal generation circuit operates to shift the ‘ramp’ signal up by a voltage Vslp(p−p)+Vhys when transitioning from buck to boost mode, and to shift ‘ramp’ back down by Vslp(p−p)+Vhys when transitioning from boost to buck mode, thereby enabling the converter to operate in buck mode or boost mode only, with no need for an intermediate buck-boost region.

This disclosure relates to radio frequency (RF) power converters and methods of operating the same. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out (LDO) regulation circuit, and an RF filter. The RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from the LDO regulation circuit. The RF filter is operable to alternate between a first RF filter topology and a second RF filter topology. In the first RF filter topology, the RF filter is configured to convert the pulsed output voltage from a switching circuit into the supply voltage. The RF filter in the second RF filter topology is configured to filter the supply voltage from the LDO regulation circuit to reduce a ripple variation in a supply voltage level of the supply voltage. As such, the RF filter provides greater versatility.

This disclosure relates to radio frequency (RF) power converters and methods of operating the same. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out (LDO) regulation circuit, and an RF filter. The RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from the LDO regulation circuit. The RF filter is operable to alternate between a first RF filter topology and a second RF filter topology. In the first RF filter topology, the RF filter is configured to convert the pulsed output voltage from a switching circuit into the supply voltage. The RF filter in the second RF filter topology is configured to filter the supply voltage from the LDO regulation circuit to reduce a ripple variation in a supply voltage level of the supply voltage. As such, the RF filter provides greater versatility.

A device (200) includes a circuit (202) and a driver stage (204) therefor. The circuit includes two sub-circuits (231 and 232). The driver stage includes switcher logic (206) that produces signals that control switching on and off of the sub-circuits. The switcher logic also produces other signals in advance of the signals that control the switching of the sub-circuits. The driver stage includes delay compensations circuits (221 and 222), coupled to the switcher logic and to the circuit, that produce timing signals for the switcher logic. The timing signals are closely aligned with moments that a changing voltage at a node between the sub-circuits passes through threshold voltages. The timing signals compensate for all delays of signals through the device such that a period that both sub-circuits are off is minimized, while ensuring that both sub-circuits are not on at a same time.

A switching power converter includes a voltage source that provides an input voltage Vin to an unregulated DC/DC converter stage and at least one buck-boost converter stage to produce a desired output voltage Vout. The unregulated DC/DC converter stage is adapted to provide an isolated voltage to the at least one regulated buck-boost converter stage, wherein the unregulated DC/DC converter stage comprises a transformer having a primary winding and at least one secondary winding and at least one switching element coupled to the primary winding. The at least one buck-boost converter stage is arranged to operate in a buck mode, boost mode or buck-boost mode in response to a mode selection signal from a mode selection module. By influencing the pulse width modulation output power controller the at least one buck-boost converter stage is arranged to produce one or multiple output voltages.

A constant on-time switching converter includes a switching circuit, an on-time control circuit, a comparing circuit and a logic circuit. The switching circuit has a first switch and is configured to provide an output voltage to a load. The on-time control circuit generates an on-time control signal to control the on-time of the first switch. The comparing circuit compares the output voltage of the switching circuit with a reference signal and generates a comparison signal. The logic circuit generates a control signal to control the first switch based on the on-time control signal and the comparison signal. When the switching frequency of the switching circuit approaches an audible range, the switching converter enters into a sleep mode, the on-time control signal is reduced to increase the switching frequency of the switching circuit.

A power converting circuit includes an upper gate switch, a transistor, a current source circuit, a comparator circuit, a delay circuit, and a pulse width modulation signal generating circuit. The transistor and the current source circuit provide a reference signal. The comparator circuit generates a comparing signal according to the reference signal and an output signal provided by the upper gate switch. The delay circuit generates a delay signal according to the comparing signal and a clock signal. The pulse width modulation signal generating circuit generates a control signal for the upper gate switch according to the delay signal and the clock signal for configuring the conduction status of the upper gate switch. The power converting circuit adjusts the conduction time of the upper gate switch according to the reference signal and the output signal.