Abstract: The present disclosure discloses an LLC resonant converter and a method for suppressing ripples in output voltage of the LLC resonant converter. The LLC resonant converter comprises: a half-bridge or full-bridge chopper having a driving circuit, an inductance-capacitance series resonant network coupled to the chopper, an isolation transformer coupled to the resonant network, and a rectification and filtering circuit coupled to the isolation transformer; a feedforward controller coupled to generate a feedforward signal based on an input voltage; and a controlled oscillator coupled to receive the feedforward signal from the feedforward controller and to control an operating frequency of the chopper via the driving circuit based on the feedforward signal. Thus, a feedforward correction is provided for the LLC resonant converter, so that ripples in a DC output voltage of the LLC resonant converter are reduced.

Abstract: Example isolated AC-DC power supplies include a PFC converter coupled to an AC input, a DC-DC converter coupled between the PFC converter and a DC output, and a controller configured to control switching operation of the DC-DC converter. A pulse modulator is coupled to an output of the PFC converter to receive a signal representative of voltage ripple at the output of the PFC converter, and is configured to modulate a pulse signal based on an amplitude of the voltage ripple. A pulse demodulator is coupled to the pulse modulator to receive the modulated pulse signal, and is configured to demodulate the modulated pulse signal and provide a demodulated signal to adjust switching operation of the DC-DC converter. Also disclosed are methods for controlling isolated AC-DC power supplies.

Abstract: The present disclosure discloses an LLC resonant converter and a method for suppressing ripples in output voltage of the LLC resonant converter. The LLC resonant converter comprises: a half-bridge or full-bridge chopper having a driving circuit, an inductance-capacitance series resonant network coupled to the chopper, an isolation transformer coupled to the resonant network, and a rectification and filtering circuit coupled to the isolation transformer; a feedforward controller coupled to generate a feedforward signal based on an input voltage; and a controlled oscillator coupled to receive the feedforward signal from the feedforward controller and to control an operating frequency of the chopper via the driving circuit based on the feedforward signal. Thus, a feedforward correction is provided for the LLC resonant converter, so that ripples in a DC output voltage of the LLC resonant converter are reduced.

Abstract: A constant current control circuit includes a current source output module and at least two output circuits. Each of the output circuits includes an automatic constant current regulating module, a power transistor drive and control module electrically coupled to automatic constant current regulating module, and a load module formed of one or more LED devices and electrically coupled to a power transistor drive and control module. The constant current control circuit in operation tracks changes in current of each output circuit and regulates the currents of all the output circuits accordingly.

Abstract: Disclosed is a user interest recommending method and apparatus, where the method includes: obtaining, according to user-generated content of a social network, interest label information of users; clustering, according to the obtained interest label information, users having a same category of interest labels to form a cluster; and recommending interest labels of the users in the same cluster to the users in the cluster, and/or recommending the users in the same cluster to one another as friends with same interests. Because the interest labels of the users are obtained from user-generated content, accuracy of matching the interest labels is high. The interest labels or friends are recommended to the users in the cluster that is formed based on high accuracy, so the recommending accuracy is high, which improves recommending efficiency and the user interest labels.

Abstract: The invention relates to digital television authentication system and method. The system includes a digital television having a digital television master chip; an SIM card module with a built-in SIM card, connected to the digital television master chip, and an authentication server wirelessly connected to the SIM card. The SIM card module includes a symmetric key generation unit used for generating a symmetric encryption key CT according to a Session Key (SEK) received by the SIM card and an identity (ID) of the SIM card; and a CW acquisition unit used for decrypting, according to the symmetric encryption key CT, an ECW sent by the authentication server, to obtain a CW. The authentication server includes an SEK generation unit used for randomly generating a string and taking the string as an SEK; and an SEK sending unit used for sending the SEK to the SIM card module.

Abstract: A constant current control circuit includes a current source output module and at least two output circuits. Each of the output circuits includes an automatic constant current regulating module, a power transistor drive and control module electrically coupled to automatic constant current regulating module, and a load module formed of one or more LED devices and electrically coupled to a power transistor drive and control module. The constant current control circuit in operation tracks changes in current of each output circuit and regulates the currents of all the output circuits accordingly.

Abstract: An ion source using a field emission device is provided. The field emission device includes an insulative substrate, an electron pulling electrode, a secondary electron emission layer, a first dielectric layer, a cathode electrode, and an electron emission layer. The electron pulling electrode is located on a surface of the insulative substrate. The secondary electron emission layer is located on a surface of the electron pulling electrode. The cathode electrode is located apart from the electron pulling electrode by the first dielectric layer. The cathode electrode has a surface oriented to the electron pulling electrode and defines a first opening as an electron output portion. The electron emission layer is located on the surface of the cathode electrode and oriented to the electron pulling electrode.

Abstract: A method for making a field emission device includes the following steps. An insulative substrate is provided. An electron pulling electrode is formed on the insulative substrate. A secondary electron emission layer is formed on the electron pulling electrode. A first dielectric layer is fabricated. The first dielectric layer has a second opening to expose the secondary electron emission layer. A cathode plate having an electron output portion is provided. An electron emission layer is formed on part surface of the cathode plate. The cathode plate is placed on the first dielectric layer. The electron output portion and the second opening have at least one part overlapped, and at least one part of the electron emission layer is oriented to the secondary electron emission layer via the second opening.

Abstract: A field emission device includes an insulative substrate, an electron pulling electrode, a secondary electron emission layer, a first dielectric layer, a cathode electrode, and an electron emission layer. The electron pulling electrode is located on a surface of the insulative substrate. The secondary electron emission layer is located on a surface of the electron pulling electrode. The cathode electrode is located apart from the electron pulling electrode by the first dielectric layer. The cathode electrode has a surface oriented to the electron pulling electrode and defines a first opening as an electron output portion. The electron emission layer is located on the surface of the cathode electrode and oriented to the electron pulling electrode.

Abstract: An ion source using a field emission device is provided. The field emission device includes an insulative substrate, an electron pulling electrode, a secondary electron emission layer, a first dielectric layer, a cathode electrode, and an electron emission layer. The electron pulling electrode is located on a surface of the insulative substrate. The secondary electron emission layer is located on a surface of the electron pulling electrode. The cathode electrode is located apart from the electron pulling electrode by the first dielectric layer. The cathode electrode has a surface oriented to the electron pulling electrode and defines a first opening as an electron output portion. The electron emission layer is located on the surface of the cathode electrode and oriented to the electron pulling electrode.

Abstract: A method for making a field emission device includes the following steps. An insulative substrate is provided. An electron pulling electrode is formed on the insulative substrate. A secondary electron emission layer is formed on the electron pulling electrode. A first dielectric layer is fabricated. The first dielectric layer has a second opening to expose the secondary electron emission layer. A cathode plate having an electron output portion is provided. An electron emission layer is formed on part surface of the cathode plate. The cathode plate is placed on the first dielectric layer. The electron output portion and the second opening have at least one part overlapped, and at least one part of the electron emission layer is oriented to the secondary electron emission layer via the second opening.

Abstract: A field emission device includes an insulative substrate, an electron pulling electrode, a secondary electron emission layer, a first dielectric layer, a cathode electrode, and an electron emission layer. The electron pulling electrode is located on a surface of the insulative substrate. The secondary electron emission layer is located on a surface of the electron pulling electrode. The cathode electrode is located apart from the electron pulling electrode by the first dielectric layer. The cathode electrode has a surface oriented to the electron pulling electrode and defines a first opening as an electron output portion. The electron emission layer is located on the surface of the cathode electrode and oriented to the electron pulling electrode.

Abstract: A sputter ion pump includes one vacuum chamber, two parallel anode poles and one cold cathode electron emitter. The vacuum chamber includes at least one aperture located in an outer wall thereof. The two parallel anode poles are positioned in the vacuum chamber and arranged in a symmetrical configuration about a center axis of the vacuum chamber. The cold cathode electron emission device is located on or proximate the outer wall of the vacuum chamber and faces a corresponding aperture. The cold cathode electron emission device is thus configured for injecting electrons through the corresponding aperture and into the vacuum chamber. The sputter ion pump produces a saddle-shaped electrostatic field and is free of a magnetic field. The sputter ion pump has a simplified structure and a low power consumption.

Abstract: A reference leak (10) includes a first substrate (20), a second substrate (40) disposed and bonded on the first substrate, and predetermined numbers of leak channels (14) defined in at least one of the first and second substrates. Oblique walls of the leak channels are formed by crystal planes of the at least one of the first and second substrates, the oblique walls thereby being aligned according to such crystal planes. A method for making a reference leak is also provided.

Abstract: An exemplary field emission cathode includes an electrically conductive layer and an electron-emitting member formed thereon. The electron-emitting member includes an electron-emitting material configured for emitting electrons and a getter material configured for collecting outgassed materials. An exemplary planar light source includes an anode and a cathode spaced apart from the anode. The anode includes a first electrically conductive layer and a fluorescent layer formed on an inner surface of the first electrically conductive layer. The cathode includes a second electrically conductive layer and an electron-emitting member formed on an inner surface of the second electrically conductive layer which faces toward the fluorescent layer. The electron-emitting member includes an electron-emitting material and a getter material.

Abstract: A sputter ion pump includes one vacuum chamber, two parallel anode poles and one cold cathode electron emitter. The vacuum chamber includes at least one aperture located in an outer wall thereof. The two parallel anode poles are positioned in the vacuum chamber and arranged in a symmetrical configuration about a center axis of the vacuum chamber. The cold cathode electron emission device is located on or proximate the outer wall of the vacuum chamber and faces a corresponding aperture. The cold cathode electron emission device is thus configured for injecting electrons through the corresponding aperture and into the vacuum chamber. The sputter ion pump produces a saddle-shaped electrostatic field and is free of a magnetic field. The sputter ion pump has a simplified structure and a low power consumption.

Abstract: An ionization vacuum gauge includes a linear cathode, an anode, and an ion collector. The linear cathode, the anode, and the ion collector are concentrically aligned and arranged from center to outer, in that order. The linear cathode includes a linear base and a field emission film deposited coating on the linear base. The ionization vacuum gauge with low power consumption can be used in a high vacuum system and/or some special vacuum system that is sensitive to heat and light. Such a gauge can be used to determine, simply yet accurately, pressures at relatively high vacuum levels.

Abstract: A method for making a reference leak includes the steps of: (a) preparing a substrate; (b) forming a patterned catalyst layer on the substrate, the patterned catalyst layer comprising one or more catalyst blocks; (c) forming one or more elongate nano-structures extending from the corresponding catalyst blocks by a chemical vapor deposition method; (d) forming a leak layer of one of a metallic material, a glass material, and a ceramic material on the substrate with the one or more elongate nano-structures partly or completely embedded therein; and (e) removing the one or more elongate nano-structures and the substrate to obtain a reference leak with one or more leak holes defined therein.

Abstract: A field emission lamp (30) includes a tube (31) having a closed end and an open end, an encapsulation board (38) mated with the open end, an anode layer (32) formed on an inner surface, a fluorescence layer (33) formed on the anode layer, a cathode down-lead pole (342) located at the encapsulation board, a cathode fixing pole (341) located at the closed end, a cathode filament (34) having a carbon nanotube layer formed on a surface thereof fixed between the cathode down-lead pole and the cathode fixing pole, an anode down-lead ring (321) located at the anode layer near the open end, and an anode down-lead pole (322) located at the encapsulation board and electrically connected with the anode down-lead ring. The field emission lamp has a simple structure, thereby having an enhanced production rate and a reduced cost.