Abstract: A motor having a reverse-rotation preventing unit, comprises: a casing; a stator fixedly-coupled to an inside of the casing; a primary rotor rotatably inserted into the stator; a motor shaft coupled to the primary rotor; a secondary rotor having a permanent magnet and rotatably inserted into an air gap between the stator and the primary rotor; a locking unit installed at an inner wall of the casing; a ratchet unit rotatably coupled to the secondary rotor, and locked or unlocked to/from the locking unit when the secondary rotor is forward-rotated or reverse-rotated, for rotating the secondary rotor in a forward direction; and a position setting unit for moving the ratchet unit to a locking position or a unlocking position by a difference between a centrifugal force generated when the secondary rotor is rotated and its restoration force. In the present invention, the motor is only forward-rotated without being reverse-rotated and thus a reliability thereof is enhanced.

Abstract: A leakage current measurement apparatus for measuring leakage currents is disclosed. The leakage current measurement apparatus automatically selects one of non-inductive shunt resistors of 10?, 100?, and 1000? and measures leakage currents of an outdoor isolation material for an ultra-high voltage. Additionally, the leakage current measurement apparatus is capable of measuring a relatively wide range of leakage currents with a relatively high precision, even at a remote location, as a measurement range is automatically adjusted within measurement ranges preset by a user when leakage currents of an outdoor isolation material change, and being protected against a surge possibly generated by an ultra-high voltage. Also, it can remotely measure in real-time leakage currents of an outdoor isolation material installed at a remote location over Ethernet.

Abstract: The present invention relates to a method and an apparatus for continuously separating aromatic dialdehyde from a reaction mixture obtained by gas-phase oxidation of dimethylbenzene. The method for continuously separating aromatic dialdehyde includes the steps of congealing aromatic dialdehyde by cooling the gas-phase reaction mixture including the aromatic dialdehyde, which is obtained by gas-phase oxidation of dimethylbenzene, to 5-70° C. and separating the congealed aromatic dialdehyde from the remaining reaction mixture. Using the method and apparatus in accordance with the present invention, aromatic dialdehyde can be effectively and selectively separated from a reaction mixture obtained by gas-phase oxidation of dimethylbenzene in high yield.

Abstract: The present invention provides a speaker module connectable to an earphone jack of a mobile phone and a method for using same. The speaker module comprises a microphone which converts voice signals into electrical signals, a speaker which converts electrical signals into acoustic signals, an amplifier which amplifies electrical signals, and a plug for connecting with the earphone jack of the mobile phone. Further, the plug can additionally comprise a terminal for sensing whether or not the speaker module is connected to the earphone jack terminal of the mobile phone.

Abstract: A rotor of a BLDC motor includes: a rotor divided into a north pole and a south pole on the basis of a magnetic pole separating line; and a stator at which the rotor is disposed with an air gap, the stator having a first pole shoe, a second pole shoe and a pair of detent grooves at its inner surface, wherein an air gap forming portion for enlarging an air gap between the rotor and the detent grooves is formed at both end portions of the rotor where the magnetic pole separating line passes, so that the rotor can maintain the motor performance and reduce resonance noise by reducing only higher degree of cogging torque from cogging torque generated when the motor is driven.

Abstract: A hybrid induction motor comprises a stator fixedly installed in a casing, an induction rotor rotatably inserted into a center of the stator and having a shaft at a center thereof, a first synchronous rotor free-rotatably installed between the stator and the induction rotor in a circumferential direction of the shaft, and a second synchronous rotor facing the first synchronous rotor and free-rotatably installed between the stator and the induction rotor in a longitudinal direction of the shaft.

Abstract: The hybrid induction motor includes a housing; a stator installed in the housing and having a stator core portion and a stator coil portion; a rotor coupling body having a rotary shaft rotatably installed in at the housing, a cage rotor portion rotating integrally with the rotary shaft, and a permanent magnet rotor portion coupled to a circumference of the cage rotor portion with a certain air gap so as to be freely rotatable with respect to the rotary shaft; and a reverse rotation preventing switch, when the rotary shaft rotates reversibly, coming in contact with the permanent magnet rotor portion which is moved along the shaft by thrust generated by the rotor coupling body and cutting off power being supplied to the stator coil portion.

Abstract: An induction motor having a reverse-rotation preventing function, comprises: a stator provided with a winding coil generating flux by a current; an induction rotor provided with a cage and rotatably inserted in the stator, wherein a rotary shaft is coupled to its inside; a synchronous rotor provided with a permanent magnet and rotatably coupled between the stator and the induction rotor; an induction-force generating unit generating a force for moving the synchronous rotor in an axial direction; and a rotation preventing unit preventing a reverse rotation by fixing the synchronous rotor moved by the induction-force generating unit at the time of reverse rotation of the synchronous rotor.

Abstract: Disclosed herein is an ELF or LF magnetic field measuring system, which can easily measure each magnetic field component existing in a free space generated by electric appliances or in a human body phantom filled with a specific fluid. A 3-axes magnetic field probe for use in the magnetic field measuring system comprises resistive lines in a protective sleeve rod electrically connected to the transmission board, an isotropic sensing head having a cubic shape, one end of the protective sleeve rod being rigidly connected to a corner point of the cubic sensing head where three faces coincide, and three bobbins adhered to three adjacent faces which coincide at a corner point diagonally opposite to the first corner point. A coil is wound on the periphery of each of the bobbins. The sensor is moved by an automatic mechanical machine to scan a pre-programmed surface where the magnetic field distribution is to the evaluated.

Abstract: The present invention relates to a method for preparing high-purity terephthalaldehyde from terephthalaldehyde crystal containing impurities by recrystallization using an antisolvent. Low-purity terephthalaldehyde prepared by a conventional method, which contains a small amount of impurities, is dissolved in a solvent and recrystallized using water as antisolvent to obtain high-purity terephthalaldehyde. The invention is significantly advantageous in using water only as antisolvent. Also, the purification process takes short time and is economical and environment-friendly.

Abstract: Provided is a catalyst for partial oxidation of methylbenzenes comprising the compound represented by the following formula 1 and, optionally, a fire-resistant inorganic support: WOx??(1) where W stands for a tungsten atom, O stands for an oxygen atom and x is a number determined by the oxidation state of W. Also provided is a method for producing aromatic aldehydes from partial oxidation of methylbenzenes in gas phase using molecular oxygen using the afore-mentioned catalyst. The catalyst of the present invention can be prepared easily compared with conventional multi-component oxide catalysts. And, aromatic aldehydes can be produced from methylbenzenes with high selectivity and yield.

Abstract: The present invention discloses a stator of a motor including a circular stator core formed by stacking a plurality of sheets, a plurality of bobbins fixed to the inner circumferential surface of the stator core at predetermined intervals and rotatably connected to each other, and stator coils wound around the outer circumferential surfaces of the bobbins to be connected to each other, and a method for manufacturing the same. The stator of the motor can reduce an assembly time by omitting a process for wiring the stator coils, and also reduce a number of components and manufacturing expenses by omitting a wiring PCB.

Abstract: A blowing fan includes: a hub connected to a rotational shaft of a motor and receiving a driving force of the motor; and a plurality of blades connected at equal intervals in a circumferential direction of the hub and generating a blowing force, in which a connection between the blades and the hub has an area-reduced form in order to reduce a rigidity of the connection portion. The rigidity between a hub where a rotational shaft is fixed and a blade is weakened to lower a torsional resonant frequency of the rotational shaft. Thus, a noise of a refrigerator is considerably reduced.

Abstract: A dual-mode mobile terminal is disclosed in which a switching between the modes is performed. The dual-mode mobile terminal of the present invention is implemented with a single CPU, two or more dual-port randon access memories (DPRAMs) and two or more MODEMs along with interface units (IUs) that prevents the occurrence of interference between parts for respective modes when the CPU and the MODEMs communicate with each other via the DPRAMs in a mobile communication terminal that use a single central processing unit and a plurality of modem chips. The IUs perform control operations so that part of signals to be applied to each of the MODEMs is/are applied only when an activation signal for the MODEM is enabled. The IUs may be implemented with logic gates, and the part of signals include an interrupt signal allowing each MODEM to be released from a sleep state.

Abstract: An oscillating reluctance motor includes a rotor having a center on which a rotational shaft is fixed thereto, and a pair of teeth protruding from said rotational shaft and arranged in positions opposite to each other; a stator in which a cylindrical space is formed so that the rotor can rotate and first and second winding parts are formed; rotation control means which is installed between the rotor and a stator to control rotation of the rotor, wherein a first winding coil is wound on the first winding part, a second winding coil is wound on the second winding part and the first winding part and the second winding part are formed having an angle centering around the rotational shaft as a pair so that the rotor can perform periodical rotation movement.

Abstract: The present invention provides a speaker module connectable to an earphone jack of a mobile phone and a method for using same. The speaker module comprises a microphone which converts voice signals into electrical signals, a speaker which converts electrical signals into acoustic signals, an amplifier which amplifies electrical signals, and a plug for connecting with the earphone jack of the mobile phone. Further, the plug can additionally comprise a terminal for sensing whether or not the speaker module is connected to the earphone jack terminal of the mobile phone.