摘要:
A motor drive system wherein an LC circuit exists between an inverter and a motor is such that switching of semiconductor switching elements Su to Sw and Sx to Sz configuring the inverter is controlled by an on-signal formed of a first on-signal, a second on-signal, and an off-state period of a time the same as the first on-signal provided between the first on-signal and second on-signal, and by an off-signal formed of a first off-signal, a second off-signal, and an on-state period of a time the same as the first off-signal provided between the first off-signal and second off-signal, and surge voltage applied to an input terminal of the motor is suppressed by the time of the first on-signal and the time of the second off-signal being set to one-sixth of a resonance cycle specific to the LC circuit.
摘要:
A motor drive system wherein an LC circuit exists between an inverter and a motor is such that switching of semiconductor switching elements Su to Sw and Sx to Sz configuring the inverter is controlled by an on-signal formed of a first on-signal, a second on-signal, and an off-state period of a time the same as the first on-signal provided between the first on-signal and second on-signal, and by an off-signal formed of a first off-signal, a second off-signal, and an on-state period of a time the same as the first off-signal provided between the first off-signal and second off-signal, and surge voltage applied to an input terminal of the motor is suppressed by the time of the first on-signal and the time of the second off-signal being set to one-sixth of a resonance cycle specific to the LC circuit.
摘要:
A high power factor rectifier circuit, provided with switching sections connected to an AC power supply for converting an AC voltage to a DC voltage, is formed with a bypass circuit provided. The bypass circuit, when the voltage of the AC power supply becomes higher than the voltage across a smoothing capacitor provided on the DC output side, makes a charge current flowing from the AC power supply to the capacitor bypass the switching section by making the switching section out of conduction. Thus, a rectifier circuit is provided which can be safely operated without causing any damage, or with minimized damage, even though an inrush current flows at turning-on the power or at recovery from a power interruption.
摘要:
A power supply device that is able to switch between rectifier circuits in accordance with the voltage of a multi-phase AC power supply, and able to accommodate different power supply voltages. The power supply device has rectifier circuits that include a first circuit that rectifies a line voltage of the AC power supply, converting it into a direct current voltage of a first predetermined value, when the voltage of the AC power supply is a predetermined value or less, and a second circuit that rectifies a phase voltage of the AC power supply, converting it into a direct current voltage of a second predetermined value, when the voltage of the alternating current power supply exceeds the predetermined value. The first and second circuits operate in such a way that the AC input current is of the same phase as the voltage of the AC power supply.
摘要:
An electric power converter circuit includes a rectifying circuit having diodes, a coil, and a full-bridge circuit including switching devices, which are connected in cascade to an AC power supply 1, to convert an AC to a DC and to further convert the concerted DC to an AC. The converter circuit further includes a series circuit having a capacitor and a switching device, and connected between the DC terminals of the full-bridge circuit. One of the switching devices on the upper arm and one of the switching devices on the lower arm are turned simultaneously ON for a certain period of time. The electric power converter circuit facilitates reducing the number of the constituent parts, size, weight and manufacturing costs thereof.
摘要:
A miniaturized direct-current switch with which power loss is reduced when establishing continuity of a direct-current path is provided. The direct-current switch includes an electronic open/close switch inserted in a direct-current path along which a direct current flows in order to make the direct-current path an open circuit or a closed circuit, a parallel mechanical open/close switch connected in parallel to the electronic open/close switch, and a switch control circuit that controls the opening or closing time difference mutually between the parallel mechanical open/close switch and the electronic open/close switch, wherein the switch control circuit makes the parallel mechanical open/close switch a closed circuit a predetermined time after the electronic open/close switch has been made a closed circuit.
摘要:
In the present invention, forming is carried out by employing casting to rapidly solidify molten material comprising a copper base alloy containing 3 to 20% Ag (mass % hereinafter), 0.5 to 1.5% Cr and 0.05 to 0.5% Zr. Next, an aging treatment for precipitation is carried out at 450 to 500° C., and the formed article is obtained by precipitation strengthening. In addition, in the aforementioned copper base alloy, molten material comprising a copper base alloy containing Ag in the amount of 3 to 8.5% is solidified by casting, and the solidified article or the hot worked article thereof is subjected to an aging treatment for precipitation and a thermomechanical treatment using forging or rolling, and the casting is obtained by forming the material into a specific shape and carrying out precipitation strengthening.
摘要:
In order to obtain a desired metal structure in a metal or alloy part having discontinuous portions, the metal or alloy part to be treated is inserted into a mold having a simple outer surface configuration. Thereafter the metal or alloy part to be treated is heated together with the mold.
摘要:
An entirely integrated EMI filter is based on a flexible multi-layer strip material. An EE or EI core comprises two side pillars and one middle pillar and forms a closed magnetic circuit. The middle pillar has an air gap. A first winding and a second winding respectively are wound around the two side pillars in a same winding direction. The middle pillar is wound with a third winding and a fourth winding, or with only a fifth winding. Passive components (e.g., all passive components) of the EMI filter are integrated into one core so that in its differential mode, insertion loss is significantly reduced, the size and volume are reduced, and the distribution constant of the EMI filter has less impact on the filter's performance.
摘要:
An integrated structure of common-mode inductors and differential-mode capacitors in an EMI filter realized using a flexible circuit board, including: a closed magnetic circuit formed by a first magnetic core and a second magnetic core, optionally including an air gap formed in a middle pillar of the magnetic cores, and with a flexible printed circuit board (FPC) wound on at least one pillar, the FPC formed by laminating alternating insulating and copper foil layers. The integrated structure of inductors and capacitors is advantageous in reducing the volume of the EMI filter and improving the power density of an electronic power transformer.