33results about How to "Reduce the turns ratio" patented technology

DC/DC converter has a transformer having primary coils connected to an input side and secondary coils connected to an output side. Each primary coil connects a full-bridge circuit comprising two switches on two legs, the primary coil being connected between the switches on each leg, each full-bridge circuit being connected in parallel wherein each leg is disposed parallel to one another, and the secondary coils connected to a rectifying circuit. An outer loop control circuit that reduces ripple in a voltage reference has a first resistor connected in series with a second resistor connected in series with a first capacitor which are connected in parallel with a second capacitor. An inner loop control circuit that reduces ripple in a current reference has a third resistor connected in series with a fourth resistor connected in series with a third capacitor which are connected in parallel with a fourth capacitor.

A regulated power factor corrected power supply apparatus is provided. The apparatus includes an input rectifier circuit for receiving an input AC voltage and outputting a full-wave rectified DC voltage. A single-stage isolated buck-type converter is coupled with the input circuit. The converter circuit comprises an isolated buck-type converter circuit including an isolation transformer. An output rectifier and semiconductor tap switch are coupled to a secondary winding of the isolation transformer. The tap switch couples a larger portion of the secondary winding to an output bulk capacitor during the portions of the input sinewave half-cycle, which are low in amplitude. The tap switch enables the single-stage isolation buck-type converter to operate over a much larger portion of the input sinewave, but also allows the converter to operate at high-efficiency over the majority of the input sinewave.

The present invention proposes a new structure for a high input VRM. This structure is similar to a simple buck converter and can simplify the 48V input VRM design. In this present invention, the interleaved voltage regulator is provided. The interleaved voltage regulator includes an integrated magnetic device for performing both transformer and output choke filter function, a first switch, a second switch, a third switch, and a fourth switch, wherein the integrated magnetic device includes a transformer having a first primary winding, a second primary winding, a first secondary winding, and a second secondary winding, a first choke filter having one end coupled to a first terminal of the first secondary winding, and a second choke filter having one end coupled to a first terminal of the second secondary winding, and the other end of the second choke filter coupled to the other end of the first choke filter to form the output terminal of the isolated voltage regulator. The first switch, the second switch, the first choke filter, and the first secondary winding form a synchronous rectifier circuit. The third switch, the fourth switch, the second choke filter, and the second secondary winding form another synchronous rectifier circuit.

The invention belongs to the technical field of electricity and relates to a single-stage photovoltaic grid-connected micro inverter and a control method thereof. The primary side of an isolation transformer achieves bidirectional excitation only through one switch tube, and the switch tube can achieve zero-voltage connection and disconnection and at the meantime transmit energy to the secondary side of the isolation transformer; the secondary side of the isolation transformer comprises two sets of high-frequency full-wave rectification circuits, which are controlled to output at a power frequency and then connected in parallel back to back, and is combined with modulation of a high-frequency switch tube of the primary side of the isolation transformer to form a pulse sequence changing by sinusoidal modulation rules and then filtered into grid-connectable power-frequency alternate current. The single-stage photovoltaic grid-connected micro inverter is simple in structure, small in size, low in cost and high in efficiency and reliability, and can be applied to other small grid-connected inverters besides photovoltaic grid-connected micro inverters; after island detection and phase lock programs are eliminated, the single-stage photovoltaic grid-connected micro inverter can be applied in a generalized mode to vehicle-mounted inverters, USB (universal serial bus) power sources, frequency converters and isolated boost DC-AC (direct current-alternate current) converters.

The invention discloses a high-voltage transmission ratio bidirectional DC converter and a control method thereof. The high-voltage transmission ratio bidirectional DC converter mainly comprises a high-voltage side three-phase full-bridge consisting of six switch tubes, a Y-delta shaped three-phase transformer and a low-voltage side three-phase bridge arm consisting of three filtering inductors and three switch tubes. The invention also provides a control method of the high-voltage transmission ratio bidirectional DC converter. The internal characteristics and the control mode of the Y-delta shaped three-phase transformer are utilized to improve the voltage transformation ratio by one time in comparison with a traditional bidirectional DC converter, so that the turn ratio of the transformer is reduced by one time, and the leakage inductance is greatly reduced, the electromagnetism compatibility of the transformer is improved. The low-voltage side three-phase inductors are parallelly connected in a staggered manner, and the output current ripple is greatly reduced after the three-phase current ripples are stacked, so that the service life of a storage battery can be favorably prolonged, and the size of a filter is favorably reduced. The high voltage side and the low voltage side both adopt the three-phase staggered shunt-wound structure, so that the current stress of the switch tubes is reduced and suitable switch tubes can be conveniently selected for high-power application occasions.

The invention discloses a multi-unit coupled inductor switch capacitor network high-gain direct-current converter. The converter comprises an input end power supply V<in>, a controllable switching tube S, a secondary side multi-winding coupled inductor, multiple two-port diode capacitor voltage-boosting units, a diode D, an output capacitor C and an output end load RL; the main circuit topology, by fully combining the characteristic of the multi-winding coupled inductor and the diode capacitor voltage-boosting units, overcomes the inherent defects of the impact current of a diode capacitor network, so that the voltage gain is obviously improved, the voltage stress of the switching tube is lowered, natural switch-off of all diodes is realized, the switching loss is lowered, and electric energy conversion efficiency is improved; and the multi-unit coupled inductor switch capacitor network high-gain direct-current converter has wide application prospect in a new energy distributed type power generation system.

The invention relates to a novel wireless fluorescent lamp which works in a bright arc transition zone, comprising a lamp tube, an electrode, a drive, a lamp casing and a lamp cup or lampshade. The electrode consists of tungsten, or molybdenum or iron. More than one layers of anti cathode sputtering films are arranged on the surface of the electrode. Super-pure argon air is filled into the lamp tube with an air-filling pressure ranging from 800 Pa to 6665Pa. The work current of the lamp tube is between 7MA and 60MA. A cold end is arranged in the lamp tube and a titanium mercury zirconium aluminum 16 alloy amalgam or an indium mercury zirconium aluminum 16 alloy amalgam is arranged in the cold end. An insulation layer is arranged between the lamp cup or lampshade and the lamp casing. The cold end extends from the lamp cup or lampshade to the insulation layer. The invention enhances light effect and surface brightness, and has small volume, high flux, enhanced reliability and long service life. The manufacture of the drive is easy, the manufacturing cost is low and the cost performance is high, furthermore, the proposal of the EMC is easy, the cost for restraining electromagnetic interference wires is low and the effect for restraining electromagnetic interference is good.

The invention belongs to the electrical technology field and relates o a single-stage-type off-grid inverter with high frequency rectification control and a control method thereof. On a primary side of a transformer, one switch tube is used to realize solar photovoltaic inversion, and the switch tube simultaneously is used to realize zero voltage opening and closing and make an isolation transformer realize bidirectional excitation. Two sets of high frequency rectification control circuits of a secondary side of the transformer make that an unsymmetrical voltage output by a secondary side winding of the transformer is effectively used. Through controlling a conduction duty ratio of a high frequency switch tube, MPPT is realized. A controllable inversion switch tube of the secondary side of the transformer carries out power-frequency alternative conduction. A resonant capacitor which is parallel to the primary side of the transformer and a transformer primary side inductor carry out resonance so that a high voltage gain exists between output and input of the inverter, and through changing a switch frequency of a primary side switch tube, adjustment can be performed. The structure of the circuit is simple, the size is small, cost is low, efficiency is high, the inverter is easy to control, reliability is high and the inverter can be widely applied.

The invention provides a switching converter, which adopts a large leakage inductance transformer to form an active clamp forward circuit, and the ratio of the leakage inductance and the excitation inductance of the transformer T is greater than 0.05. By adopting the transformer leakage inductance as filtering inductance, in addition to saving the volume and cost of the output filter inductance, the leakage inductance of the transformer can withstand a part of the input voltage when the circuit works, which can reduce the turn ratio of the transformer and provide a basis for reducing the number of turns of the winding. If the leakage inductance of the transformer is insufficient, the leakage inductance can also be increased by means of external inductance.

The invention belongs to the technical field of automatic control and power electronics, and particularly relates to a fast and reliable combustion-supporting circuit of a direct current magnetron sputtering coating power supply. By adding a combustion-supporting circuit, the voltage output by the combustion-supporting circuit is superposed with the voltage output by a high-frequency rectifier bridge of a high-frequency inverter switching power supply to reach the amplitude of the combustion-supporting starting voltage; when the starting is successful, the output current of the direct currentmagnetron sputtering power supply exceeds a starting success determination threshold value, or the output voltage of the direct current magnetron sputtering power supply is lower than a no-load voltage determination threshold value of a main power supply, the combustion-supporting circuit stops working, and the voltage and the current required by the direct current magnetron sputtering process aresupplied by the main circuit of the direct current magnetron sputtering coating power supply; once the glow is extinguished, the combustion-supporting circuit is started to output, and the output voltage of the power supply reaches the amplitude of the combustion-supporting starting voltage, so that the continuity of the coating process is ensured; and the arc energy is reduced, and the coating quality is improved.

This invention relates to a device and a method for converting voltages by a switch mode, in which, the device includes a switch supply, an inductor, diodes and capacitors, and the inductor includes a primary coil and a secondary coil coupled to each other, both ends of the secondary coil are parallel to two branches with two diodes serial to capacitors to commutate and filter the positive and negative induced voltages to form a DC supply, which can be laminated to generate a voltage meeting the requirement.

An improved electronic LCD backlighting inverter circuit for high frequency operation under low frequency pulse width modulation (PWM) for dimming control. The improved electronic LCD backlighting inverter is based on a voltage-fed push-pull LLC resonant inverter circuit configuration including a resonant inductor (L), magnetizing inductance of an output transformer (L), and resonant capacitor (C). For large values of magnetizing inductance the LLC circuit effectively becomes an LC resonant circuit. By synchronizing the high frequency switching signal and the low frequency modulation frequency using logic control circuitry, a wide dimming range and higher efficiency are achieved under PWM control.