摘要:
A digital signal processing circuit which performs average current control is disposed on a secondary side of a transformer of an isolated DC-DC converter, and a switching control signal output from the digital signal processing circuit is transmitted to a switching element included in a power factor correction converter through an isolated drive circuit. The digital signal processing circuit obtains an average value of currents supplied to an inductor in accordance with a voltage output from a bias winding of the inductor or an output from a secondary side of a current transformer which detects a drain current of the switching element. Furthermore, the average value of the currents corresponds to a waveform (full-wave rectification sine wave) of an input voltage Vi.
摘要:
A power factor correction converter includes a diode bridge arranged to perform full-wave rectification on an AC input power supply, a switching element arranged to perform switching on an output voltage thereof, an inductor arranged to pass a current interrupted by the switching element and to accumulate and emit excitation energy, a diode, and a smoothing capacitor defining a step-up chopper circuit. A digital signal processing circuit detects a phase of an input voltage, and a switching frequency of the switching element is modulated in accordance with the phase. Accordingly, the switching frequency can be appropriately modulated without depending on an input voltage, so that a wide range of input voltages can be accepted while suppressing EMI noise with a peak generated in the switching frequency and higher-order frequency components thereof.
摘要:
In a switching power supply apparatus, a comparator outputs a first determination criterion signal based on a saw-tooth wave signal whose level fluctuates with a constant period and a detection voltage signal. An inverter subjects the first determination criterion signal to reverse processing, and outputs a second determination criterion signal. The comparator outputs a first switching judgment-use signal from a monitor signal and a threshold value, and the comparator outputs a second switching judgment-use signal from the monitor signal and the threshold value. An AND circuit outputs the first switching control signal from the first determination criterion signal and the first switching judgment-use signal, and the AND circuit outputs the second switching control signal from the second determination criterion signal and the second switching judgment-use signal.
摘要:
There is obtained a laser processing method by which an excellent shape of a cut surface can be achieved and an increase in cost can be suppressed. A laser processing method includes the steps of: preparing a material to be processed; and forming a modified area in the material to be processed, by irradiating the material to be processed with laser beam. In the aforementioned step, pulsed laser beam having a continuous spectrum is focused with a lens, thereby forming a focusing line constituted by a plurality of focuses that are obtained by predetermined bands forming the continuous spectrum of the laser beam, and the material to be processed is irradiated with the laser beam such that at least a part of the focusing line is located on a surface of the material to be processed, thereby forming the modified area on an axis of the focusing line.
摘要:
A PFC converter that rapidly and highly accurately detects current passing through an inductor so as to properly improve harmonics and the power factor as well as to correctly detect the operation state. In the PFC converter, a first current value is obtained by performing sampling at the middle portion of the on-period of a switching element, and a second current value is obtained by performing sampling at the middle portion of the off-period thereof. If the first current value and the second current value are equal or substantially equal to each other, then it is determined that the operation state is a continuous current mode, and if the first current value and the second current value are not equal or substantially equal to each other, then it is determined that the operation state is a discontinuous current mode.
摘要:
A method in which activated carbon having a bulk density of at least 0.35, a particle size of 5 to 40 mesh and a water content of 50 to 120% is regenerated by being passed successively through drying, burning and reviving treatment zones of a vertical columnar furnace, which zones are maintained within temperature gradients such as to prevent explosion and oxidation or destruction of the carbon due to overheating while the carbon descends through the zones and is heated by a high temperature combustion gas flowing upwardly through the treatment zones at a rate not exceeding the minimum rate of fluidization of the descending carbon.The regenerating apparatus or furnace has gas burners mounted thereon to deliver combustion gas tangentially to a header and then to distributing ports arranged circumferentially around and internally of a columnar bed of carbon being regenerated to provide uniform temperature distribution across the bed. In an alternate construction, the columnar bed is annular, headers are provided exteriorly and interiorly of the bed, and distribution ports conduct the combustion gas through the inner and outer walls defining the annular bed.
摘要:
A PFC converter that prevents and reduces switching losses by controlling ripple of inductor current and enables application for high power usage, includes a switching device that is turned off when an inductor current flowing through an inductor reaches a first threshold value, and turned on when the inductor current reaches a second threshold value. A switching control circuit sets a reference value of the inductor current using results from an input voltage detection circuit and an output voltage detection circuit. The first threshold value is produced by adding a predetermined value to the reference value, and the second threshold value is produced by subtracting the predetermined value from the reference value.
摘要:
A low-cost PFC converter capable of detecting an inductor current including a DC component and performing appropriate correction of a power factor with low loss includes a diode bridge that rectifies an AC voltage input from an AC input power supply Vac, a series circuit including an inductor and a switching element, a rectifying and smoothing circuit that is connected in parallel to the switching element and that includes a diode and a smoothing capacitor, and a digital signal processing circuit that performs on/off control on the switching element so that an input current input from the AC input power supply Vac has a similar waveform with respect to an AC voltage. A current flowing through the inductor during an off period of the switching element is detected using a current detecting resistor, and a decreased voltage of the current detecting resistor is sampled at the middle of the off period of the switching element, thereby detecting an average value of the input current.
摘要:
Method for surface treating a die made of metal in which a low energy, pulsed electron beam, which does not scatter, performs a treatment over a wide area due to presence of anode plasma in a chamber in which the electron beam is formed to smooth and gloss a surface of the die and increase a surface hardness and corrosion resistance of the die. The irradiation may be performed with an energy density not less than 1 J/cm2 per pulse, at least 5 pulse irradiations and a pulse duration of at least 1 μs. A die subjected to the surface treatment method exhibits improved surface smoothness and glossiness, as well as high corrosion resistance.
摘要翻译:用于表面处理由金属制成的管芯的方法,其中不散射的低能量的脉冲电子束由于在其中形成电子束平滑的室中存在阳极等离子体而在广泛的区域上进行处理, 光泽模具的表面并增加模具的表面硬度和耐腐蚀性。 照射可以以每脉冲1J / cm 2以上的能量密度进行,至少5次脉冲照射和至少1μs的脉冲持续时间。 经受表面处理方法的模具表现出改善的表面光滑度和光泽度以及高耐腐蚀性。
摘要:
The regenerating apparatus or furnace has gas burners mounted thereon to deliver combustion gas tangentially to a header and thence to distributing ports arranged circumferentially around and internally of a columnar bed of carbon being regenerated to provide uniform temperature distribution across the bed. In an alternate construction, the columnar bed is annular, headers are provided exteriorly and interiorly of the bed, and distribution ports conduct the combustion gas through the inner and outer walls defining the annular bed.