摘要:
An electronic ballast is provided for adjustable filament preheating of a discharge lamp based on output current symmetry. A power converter receives DC power and outputs AC power. A starting circuit generates a high voltage for starting the lamp. A control circuit controls the AC power output from the power converting circuit. A symmetry determining circuit determines a positive-negative symmetrical state of the AC power output to the lamp with respect to ground. After lamp startup, the control circuit enters a filament heating operation in which the output frequency of the power converting circuit is controlled to a first frequency. At one or more predetermined current detection points during the filament heating operation, the control circuit checks the symmetry state. If the output current is symmetrical at the current detection point, the control circuit ends the frequency heating operation and enters steady state operation with an output frequency of the power converter controlled to a second frequency for maintaining lamp lighting. If the output current is asymmetrical at the current detection point, the control circuit increases the output current to the lamp and continues the frequency heating operation.
摘要:
There is provided a high-intensity discharge lamp lighting apparatus to be loaded with a plurality of types of high-intensity discharge lamps and connected with any one of the lamps to be lighted, and the apparatus comprises a power conversion circuit for converting power supplied from a DC power source to supply the power to a high-intensity discharge lamp and a lighting control circuit for controlling the supply power of the power conversion circuit, wherein the type of the connected high-pressure discharge lamp is determined based upon a change rate of an electric characteristic of the high-intensity discharge lamp during a specific period, and the connected high-intensity discharge lamp is lighted with a desired electric characteristic selected based upon the determination result, thereby enabling discrimination of types of rated power of the plurality of types of lamps by the same detection method and the same control method irrespective of states in starting of the lamps, and by enabling the discrimination before stable lighting of the lamp, it is possible to start the discharge lamp with little stress applied to the discharge lamp.
摘要:
A high pressure discharge lamp lighting device in this invention comprises a converter, an inverter, an igniter, a controller, and a pulse voltage detection circuit. The converter outputs the direct current voltage. The inverter converts the direct current voltage into the lighting voltage which is alternating current voltage, and applies the lighting voltage to the high pressure discharge lamp through an output terminal. The igniter is configured to output the pulse voltage superimposed on the lighting voltage, whereby the starting voltage is applied to the high pressure discharge lamp. The controller is configured to control the igniter to allow the igniter to superimpose the pulse voltage on the lighting voltage. The pulse voltage detection circuit detects the starting voltage to output the detection signal. The starting voltage regulation circuit regulates the starting voltage to the desired voltage value of the voltage on the basis of the detection signal.
摘要:
A discharge lamp lighting device includes: a direct current power supply circuit that outputs direct current power; an inverter circuit that converts the direct current power, which is outputted by the direct current power supply circuit, into alternating current power, and supplies the alternating current power to a discharge lamp; a control circuit that controls a frequency of an output of the inverter circuit (operation frequency); and a starting detection circuit that detects beginning (starting) of a discharge in the discharge lamp. The control circuit operates in a starting improvement mode, in which the operation frequency is lowered than an operation frequency in a lighting mode, during a predetermined time from when the starting of the discharge lamp is detected by the starting detection circuit 4 during a no-load mode. Thereafter, the control circuit shifts to the lighting mode in which lighting of the discharge lamp is maintained. In such a way, the discharge lamp can be smoothly shifted to stable lighting.
摘要:
A device includes a direct current power circuit configured to convert an alternating current voltage from an alternating current power source into a direct current voltage, an output unit configured to convert a direct current from the direct current power circuit into a square wave alternating current whose polarity is inverted at a prescribed frequency and to supply the square wave alternating current to a high-pressure discharge lamp, a controller, and an anomaly detector configured to detect an instantaneous voltage drop of the alternating current power source. When the anomaly detector detects the instantaneous voltage drop, the controller switches from a normal lighting mode of controlling the output unit to supply the high-pressure discharge lamp with a square wave alternating current to a lighting maintained mode of controlling the output unit to supply the high-pressure discharge lamp with a square wave alternating current having a lower frequency than the square wave alternating current in the normal lighting mode. In this way, it is possible to maintain lighting of the high-pressure discharge lamp even upon occurrence of an instantaneous power failure, an instantaneous voltage drop, and the like.
摘要:
[Task to be Solved] One of the principal objects of the invention is to collect minute diamond particles of D50 of 20 nm and smaller, by MICROTRAC UPA 150, in high precision and high definition.[Means for Solving the Task] The minute diamond particles of the invention are recovered by a method comprising: (1) joining or combining a hydrophilic functional group with a surface of diamond powder that comprises particles of a primary particle size of 50 nm or less, so as to impart hydrophilic nature on the surface, (2) placing the hydrophilic diamond particles to hold in suspension in water to form a slurry, (3) subjecting said slurry to a hyper-centrifugal process at a centrifugal force of 4×103 G and at the same time a centrifugal load product of 200×103 G·min. or more, in order to remove by depositing a fraction of coarser particles from the slurry, said load product being defined as product of centrifugal force, loaded, in G and duration of loading in minutes, where G represents the gravitational acceleration constant; (4) adding cations to said slurry, whereby the diamond particles in suspension in the water are deposited.
摘要:
An interference analysis device that analyzes interference includes an input unit that inputs design data, a selection unit that selects an analysis region, a division unit that divides a wire into segments, a calculation unit that calculates a circuit matrix regarding a coupled line, and an analysis unit that obtains a degree of electromagnetic interference, wherein the calculation unit calculates a circuit matrix of the coupled line, using a parameter set obtained by adding an asymmetry parameter to RLGC parameters of a transmission line in the coupled line. Thus, a method for analyzing an interference of circuit wiring can be provided, which is capable of shortening a processing time substantially while maintaining high precision.
摘要:
An electronic ballast for powering a discharge lamp includes an asymmetry determination circuit functional to determine whether positive and negative polarities of an AC output current to the lamp are symmetrical. An inverter having a plurality of switching elements is coupled to a DC power source and converts the DC power to the AC output current. A control circuit is functional to control the plurality of switching elements dependent upon an operating mode and an output from the asymmetry determination circuit. The control circuit controls the switching elements in a normal mode upon receiving a determination of symmetrical current from the asymmetry determination circuit, and controls the switching elements in a restart mode for a predetermined period of time upon receiving a determination of asymmetrical current from the asymmetry determination circuit.
摘要:
A lighting apparatus of high intensity discharge lamp comprises a DC power source, a series connection of a first and a second transistors; a series connection of a first and a second capacitors connected in parallel with the series connection of the transistors; a series connection including at least an inductor and a discharge lamp connected between a connection point of the transistors and another connection point of the capacitors, and a control circuit for switching on and off of the transistors so as to supply electric power to the discharge lamp. A voltage of the first capacitor is set to be higher than that of the second capacitor corresponding to the capacitances of the first and second capacitors. Thus, the pulse height in negative or positive phase of the rectangular alternating voltage applied to the discharge lamp can be increased without increasing the output voltage from the DC power source.
摘要:
A lighting apparatus of high intensity discharge lamp comprises a DC power source, a series connection of a first and a second transistors; a series connection of a first and a second capacitors connected in parallel with the series connection of the transistors; a series connection including at least an inductor and a discharge lamp connected between a connection point of the transistors and another connection point of the capacitors, and a control circuit for switching on and off of the transistors so as to supply electric power to the discharge lamp. A voltage of the first capacitor is set to be higher than that of the second capacitor corresponding to the capacitances of the first and second capacitors. Thus, the pulse height in negative or positive phase of the rectangular alternating voltage applied to the discharge lamp can be increased without increasing the output voltage from the DC power source.