Abstract:
PURPOSE: A device and method for extracting the maximum power of a solar battery are provided to extract the maximum power without respect to the conditions of the solar battery. CONSTITUTION: A device for extracting the maximum power of a solar battery comprises a maximum power extracting system solar battery(110), a maximum power extracting unit(120), a DC-DC converting unit(130), and a battery(140). If the amount of currents increases when the device is set to extract maximum power, a voltage decreases. Therefore, the strength of power decreases. The DC-DC converting unit switches a transistor according to the ratio of on-time to the cycle of a pulse width modulation signal.
Abstract:
PURPOSE: A wireless power transfer system based on an ultrasonic wave is provided to wirelessly transfer power to an electronic device by using a wall or a ceiling, thereby saving the power lines of a building. CONSTITUTION: An ultrasonic wave transmitting transducer(201) generates an ultrasonic wave. The ultrasonic wave receiving transducer(203) converts the ultrasonic wave into electrical energy. A medium layer(202) is located between the ultrasonic wave transmitting transducer and the ultrasonic wave receiving transducer. An impedance matching layer(204) matches impedance to maximize the power transfer efficiency between the ultrasonic wave transmitting transducer and the ultrasonic wave receiving transducer.
Abstract:
PURPOSE: A method for preparing one-dimensional titanium oxide nanotubecluster anode active material for lithium rechargeable batteries is provided to improve the capacity through the increase of a lithium insertion coefficient to titanium oxide nanotubecluster by improving reaction area with electrolyte. CONSTITUTION: A method for preparing one-dimensional titanium oxide nanotubecluster anode active material for lithium rechargeable batteries comprises the steps of: performing hydrothermal synthesis of spherical titaniumoxide micro powder in strong alkali solution; controlling the pH value of the hydrothermally synthesized titanium oxide nanotubecluster; and heat-treating the titanium oxide nanotubecluster in which the pH value is controlled.
Abstract:
PURPOSE: A power managing apparatus is provided to prevent the generation of the extreme current and the extreme discharge by controlling the amount of the current outputted by a battery. CONSTITUTION: A battery(110) stores the power inputted from the outside. An extreme current prevention part(130) controls the amount of the current outputted form the battery in order to prevent the extreme current applied to the output terminal. An extreme discharge prevention part(150) controls the amount of the current outputted from the battery according to the charging state of the battery.
Abstract:
PURPOSE: A piezoelectric energy harvester and a manufacturing method thereof are provided to obtain a sufficient voltage for a switch drive of a power control circuit according to the displacement speed of a cantilever tip. CONSTITUTION: A piezoelectric layer(330a,330b) is respectively formed on the upper and lower sides of a metal core(310). A first voltage is generated by the vibration of the piezoelectric layer. A magnetostrictive layer(350a,350b) is formed on the upper side of the piezoelectric layer. The magnetostrictive layer induces the change of a magnetic field by the vibration. A coil(370) surrounds the piezoelectric layer and the magnetostrictive layer.
Abstract:
본 발명은 증폭기를 공유하는 이중 CDS/PxGA(Correlated Double Sampling/Pixel Gain Amplifier) 회로에 관한 것으로, 특히 커패시턴스에 기반하여 증폭기의 이득을 조정하는 이중 CDS/PxGA 회로에 관한 것이다. 본 발명에 따른 이중 CDS/PxGA 회로는 제 1 픽셀의 리셋 준위 및 데이터 준위를 샘플링하는 제 1 샘플링부; 제 2 픽셀의 리셋 준위 및 데이터 준위를 샘플링하는 제 2 샘플링부; 및 상기 제 1 샘플링부 및 상기 제 2 샘플링부로부터 샘플링 값을 수신하고 상기 샘플링 값을 이용하여 상기 제 1픽셀의 출력신호 및 상기 제 2 픽셀의 출력신호를 계산하고 증폭하여 출력하는 연산증폭기를 포함하고, 상기 연산증폭기의 이득은 상기 제 1 샘플링부 및 상기 제 2 샘플링부에 포함된 커패시터의 커패시턴스에 기반하여 결정된다. 본 발명은 이중 CDS/PxGA 구조를 사용함으로써 연산증폭기의 속도를 감소시키고, 연산증폭기를 공유하여 전력소모를 줄이며, 커패시터 배열을 사용하여 커패시턴스를 조정함으로써 넓은 범위의 가변 이득을 얻을 수 있다. CDS/PxGA, 커패시터 배열, 증폭기 공유
Abstract:
PURPOSE: A pre-treatment method of the surface of a polymer film is provided to facilitate the expansion and contraction of the polymer film by improving the adhesion force of the surface of the polymer film and a metal electrode. CONSTITUTION: A pre-treatment method of the surface of a polymer film for producing a polymer actuator comprises the following steps: plasma treating the polymer film using a shadow mask; setting the optimum plasma treatment time and shadow mask pattern by the thickness of the polymer film and a metal electrode to be formed on both sides of the polymer film(S100); and surface treating the polymer film using the set shadow mask pattern during the set plasma treatment time(S200).
Abstract:
PURPOSE: A piezoelectric loudspeaker system is provided to vary a sound playing location by including an electrode pad which is selectively operated. CONSTITUTION: A plurality of electrode pads(120) is formed on the upper side of a piezoelectric thin plate(110). A cotton pad is formed on the lower side of the piezoelectric thin plate. Two frames(140, 150) covers the upper side and the lower side of the piezoelectric thin plate. A switch(200) selects one electric pad for playing a sound. The signal wires of the switch are connected to the electrode pads.
Abstract:
PURPOSE: A memory access device including a multiprocessor effectively managing a plurality of processors accessing a specific memory at the same time is provided to store data or address that a plurality of processors transmits, thereby performing other tasks in different processors by removing one processor for one of access about a memory. CONSTITUTION: The first and second transaction controllers(12,17) are connected to each of the first and second processors(11,16). Each of first and second transaction controllers is connected to a memory access switch(13). A memory controller(14) is connected to the memory access switch. If the first and second processors access the memory device at the same time while the first processor accesses the memory device, the second processor stores address or data in the second transaction controller.
Abstract:
PURPOSE: A method and a device for controlling the direction sound source of a listening space are provided to achieve maximum acoustics by performing only minimum controlling operation. CONSTITUTION: A listening/non-listening space establishing unit(110) establishes a listening space or a non-listening space according to the position of a listening. The listening/non-listening space establishing unit selects the number and the position of the sound sources to use for outputting acoustics. An acoustic energy calculator(130) calculates the sound energy of the listening space and the non-listening space and the total amount of the sound energy of an acoustic signal inputted to the selected sound source. A sound source vector calculator(150) maximizes the difference in the sound energy of the listening space and the non-listening space. The sound source vector calculator minimizes the total amount of the sound energy of the acoustic signal inputted to the selected sound source. A sound pressure and phase controller(170) controls the sound pressure and the phase of the selected sound source according to the optimal sound source vector.