摘要:
A startup control method of a BLDC motor is disclosed. The method can control the BLDC motor to prevent the generation of a transient current such that the vibration of the BLDC motor can be reduced at the startup stage and perform a stable conversion into a senseless operation mode such that the startup failure rate of the BLDC motor can be reduced. The startup control method includes commutating a current applied to stator windings according to a rotor position. The method of operating the BLDC motor includes a rotor position that is forcibly aligned and so that phase commutation is performed, a back-electromotive force (back- emf) is detected from a lead voltage of a phase of a voltage which is not applied thereto after performing phase commutation and a determination is performed as to whether the detected back-emf is in a rising interval. The lead voltage of the phase of the voltage which is not applied thereto is integrated, such that if the back-emf is in a rising interval and if an instance that the integration result is greater than a predetermined value a phase commutation time point is setand conversion into a senseless operation mode is performed if the back-emf detected from the lead voltage is in a stable interval, based on a frequency of the voltage applied to the stator winding.
摘要:
A convection part of an electric oven range is provided. In the convection part, a convection motor is provided, a convection fan is connected with the convection motor, and a fan housing encloses the convection fan and it includes at least one pair of discharge ducts in opposite directions.
摘要:
The present invention relates to a high performance water gas shift catalyst and a method of preparing the same, more particularly to a high performance water gas shift catalyst comprising active components such as copper (Cu), nickel (Ni) and platinum (Pt) and a ceria (CeO2) support, which has better catalytic activity and thermal cycling durability with minimum platinum supporting amount of 1 wt % or less compared with the conventional Pt/CeO2 catalyst and LTS catalyst, and a method of preparing the same.
摘要翻译:本发明涉及一种高性能水煤气变换催化剂及其制备方法,更具体地涉及包含有效成分如铜(Cu),镍(Ni)和铂(Pt)的高性能水煤气变换催化剂和 具有较好的催化活性和热循环耐久性的二氧化铈(CeO 2 2)载体,与常规的Pt / CeO 2 2相比,铂载体的最小铂负载量为1重量%以下。 催化剂和LTS催化剂及其制备方法。
摘要:
Provided is a micro-column electron beam apparatus including: a base; an electron lens bracket on which an electron lens modulate can be fixed, mounted in a central portion of the base; an electron beam source tip module vertically disposed on the electron lens module; a pan spring plate stage module that is mounted over the base, supports the electron beam source tip module at a central portion thereof, and includes a three-coupling pan spring plate portion including first through third spring units that are coupled to the electron beam source tip module in three directions on a plane perpendicular to the vertical axis, which vertically passes the center of the electron beam source tip module, to elastically support the electron beam source tip module in three directions; a first piezoelectric actuator coupled to the pan spring plate stage module to move the electron beam source tip module along a first axis perpendicular to the vertical axis; and a second piezoelectric actuator coupled to the pan spring plate stage module to move the electron beam source tip module along a second axis perpendicular to the vertical axis and the first axis.
摘要:
A micro column electron beam apparatus having a reduced number of interconnections is provided. The micro column electron beam apparatus includes: a low temperature co-fired ceramic (LTCC) substrate; a plurality of deflector electrodes attached to a predetermined top portion of the LTCC substrate; a pad electrode placed at a top edge of the LTCC substrate and transmitting an external signal to the deflector electrodes; and a connection unit placed in the LTCC substrate and electrically connecting the deflector electrode and the pad electrode.
摘要:
Provided is a micro stage comprising: a body having a vertically perforated through-hole passing through a central portion thereof; a bobbin including a tip portion with an electron emission tip embedded in the center thereof, and passing through the through-hole of the body to be moved in the through-hole along a first axis perpendicular to a vertical direction; a first piezoelectric element disposed on the body and lengthened when a voltage is applied thereto to push the bobbin in one direction along the first axis; a second piezoelectric element disposed on the body and lengthened when a voltage is applied thereto to push the bobbin in the other direction along the first axis; and an upper cover that is coupled to an upper portion of the body and has a through-hole, through which the bobbin passes and communicates with the through-hole of the body, wherein the bobbin can be positioned as desired along the first axis by adjusting the voltages applied to the first piezoelectric element and the second piezoelectric element. Accordingly, the emission tip can be exactly and stably positioned using only the movable piezoelectric elements.
摘要:
Provided is a wafer-scale microcolumn array using a low temperature co-fired ceramic (LTCC) substrate. The microcolumn array includes a LTCC substrate having wirings and wafer-scale beam deflector arrays, which are attached to at least one side of the LTCC substrate and has an array of deflection devices deflecting electron beams. The wafer-scale microcolumn array using the LTCC substrate makes it possible to significantly increase the throughput of semiconductor wafers, simplify its manufacturing process, and lower its production cost.
摘要:
A tripod type constant velocity joint comprises a housing having three track grooves which are defined at trisected positions of the housing along a circumferential direction and extend in a radial direction; a spider having three polyhedral trunnions which are projectedly formed at trisected positions of the spider along the circumferential direction to be respectively inserted into the track grooves and each of which has at least two polygonal surfaces; inner rollers a circumferential inner surface of each of which has a curved contour for surrounding the polyhedral trunnion; a plurality of needle rollers assembled to a circumferential outer surface of each inner roller; and outer rollers each formed to be rotated through the needle rollers, to be moved in an axial direction of the inner roller, and to be moved in an axial direction of the track groove along a guide surface of the housing.
摘要:
Embodiments of methods and systems of the application can transmit data (e.g., voice) using a wireless LAN and a Bluetooth. One system embodiment can include a terminal device, an AP (access point) for communicating with the terminal device according to a first (e.g., wireless LAN) protocol by using a first frequency band among multiple frequency bands of a prescribed frequency band (e.g., ISM frequency band) and a headset for communicating with the terminal device according to a second (e.g., Bluetooth) protocol by using at least one frequency band of remaining frequency bands by excepting the first frequency band.
摘要:
A Chip on Board (COB) package which can reduce the manufacturing costs by using a general PCB as a substrate, increase a heat radiation effect from a light source, thereby realizing a high quality light source at low costs, and a manufacturing method thereof. The COB package includes a board-like substrate with a circuit printed on a surface thereof, the substrate having a through hole. The package also includes a light source positioned in the through hole and including a submount and a dome structure made of resin, covering and fixing the light source to the substrate. The invention allows a good heat radiation effect by using the general PCB as the substrate, enabling manufacture of a high quality COB package at low costs. This in turn improves emission efficiency of the light source, ultimately realizing a high quality light source.