Abstract: A convex grind method for grinding a knife includes preparing a grinding tool, first angle grinding, second angle grinding, third angle grinding and polishing. The grinding tool includes an actuator, a grinding member detachably mounted on the actuator, and two guide blocks disposed at two opposite sides of the grinding member. The grinding member has two conical grinding faces, and each of the two guide blocks is formed with a guide face disposed at a vertical state and located above each of the two conic grinding faces of the grinding member. The grinding tool performs the first angle grinding, the second angle grinding and the third angle grinding to abrade the blade of a knife. Then, the blade of the knife is polished to finish the grinding process so as to form a convex grind knife.

Abstract: A knife sharpening device contains: a main whetstone portion and a sub whetstone portion. The main whetstone portion includes a bevel seat, two stopping protrusions, at least one first support piece, at least one second support piece, and a main sharpening block. The bevel seat has a tilted face, the at least one first support piece, the at least one second support piece, the main sharpening block, and the sub whetstone portion. The sub whetstone portion includes at least one sub sharpening block, an auxiliary sharpening face, and a concave wall. Each sub sharpening block has the auxiliary sharpening face defined on a front surface thereof and corresponding to the main sharpening block of the main whetstone portion, and the concave wall is defined below the auxiliary sharpening face.

Abstract: A knife sharpening device contains: a main whetstone portion and a sub whetstone portion. The main whetstone portion includes a bevel seat, two stopping protrusions, at least one first support piece, at least one second support piece, and a main sharpening block. The bevel seat has a tilted face, the at least one first support piece, the at least one second support piece, the main sharpening block, and the sub whetstone portion. The sub whetstone portion includes at least one sub sharpening block, an auxiliary sharpening face, and a concave wall. Each sub sharpening block has the auxiliary sharpening face defined on a front surface thereof and corresponding to the main sharpening block of the main whetstone portion, and the concave wall is defined below the auxiliary sharpening face.

Abstract: An electronic device comprises a control unit, a power supply, a switch unit, a driving unit, and an illumination unit. The control unit generates a pulse width modulation (PWM) signal with a first level signal and a second level signal. The switch unit establishes a connection between the power supply and the driving unit or cuts off the connection in response to the PWM signal. The driving unit generates a variable driving voltage. The illumination unit emits light when the variable driving voltage is more than a first predetermine value, and the brightness of the illumination unit is gradually changed in response to the variable driving voltage.

Abstract: A power management circuit comprising a power-on signal input, an output terminal a control unit, a switching unit, and a discharge unit. The control unit configured to selectively turn on the switching unit to output a power-on signal to a display module and selectively turn off the switching unit to cut off an electrical connection between the power-on signal input and the output terminal. The discharge unit configured to discharge residual electrical charges in the display module when the switching unit is turned off.

Abstract: A video circuit employed in a video apparatus is configured for transmitting a video signal via an interface unit. The video circuit includes a display circuit and a compensation circuit. The display circuit switches the video apparatus into a video input mode in response to a user's operation, and blocks specific component of the video signal received from the interface unit. The compensation circuit adds a predetermined amount of direct current to the video signal.

Abstract: An electronic device capable of audio files with different formats includes a power supply, a switching circuit, an audio control module, an audio output module, and a detecting module. The power supply supplies a first voltage and a second voltage. The detecting module detects whether the format of the audio file is changed. The detecting module generates a first detecting signal within a first predetermined time period from a point in time when the format of the audio file is changed time point, and the switching circuit transmits the first voltage to the audio control module in response to the first detecting signal. The audio control module receives the second voltage and generates a first signal based on the first voltage and the second voltage. The audio output module is disabled from outputting audio signal of the audio file.

Abstract: An electronic device receives a voltage from a power source. The electronic device comprises a voltage converting module, an energy storing module, a switching module, and an illuminating module. The voltage converting module converts the voltage provided by the power source into a working voltage. The energy storing module is capable of being charged by the working voltage. The switching module is connected between the voltage converting module and the illuminating module. The illuminating module is capable of emitting light for indicating the voltage of the energy storing module. When the working voltage is suddenly changed, the switching module turns off and cuts off an electrical connection between the voltage converting module and the illuminating module. The illuminating module stops emitting light.

Abstract: A headphone detection circuit includes a voltage output module and a trigger signal producing module. The voltage output module is used to produce a first voltage to trigger an audio amplifier to output amplified left and right channel signals to a loudspeaker when the headphone port is not connected to the headphone, and produce a second voltage to trigger the audio amplifier to output the amplified left and right channel signals to the headphone port when the headphone port is connected to the headphone. The trigger signal producing module is used to trigger the processing unit to output left channel signals and right channel signals with a relative higher gain when receiving the first voltage, and trigger the processing unit to output the left channel signals and right channel signals with a relative lower gain when receiving the second voltage.

Abstract: A video circuit employed in a video apparatus is configured for transmitting a video signal via an interface unit. The video circuit includes a display circuit and a compensation circuit. The display circuit switches the video apparatus into a video input mode in response to a user's operation, and blocks specific component of the video signal received from the interface unit. The compensation circuit adds a predetermined amount of direct current to the video signal.

Abstract: An infrared remotely controlled circuit employed in an electronic device which includes a display panel and a host machine. The infrared remotely controlled circuitry includes a first remotely controlled circuit, a second remotely controlled circuit, and a microprogrammed control unit (MCU). The first remotely controlled circuit includes a first infrared receiver for mounting in the display panel and a first diode with the cathode connected to a first port of the first infrared receiver. The second remotely controlled circuit includes a second infrared receiver for mounting in the host machine and a second diode with the cathode connected to a first port of the second infrared receiver. The MCU is connected to the anode of the first diode to form a first signal input port and the anode of the second diode to form a second signal input port.

Abstract: A printed circuit board includes an insulating layer and a conductive metal layer attached on the insulating layer. The conductive metal layer is grounded and is configured for providing a ground path for electronic components mounted on the printed circuit board. The insulating layer includes an exposed portion free of the conductive metal layer thereon, and two pads are formed on the exposed portion of the insulating layer and are insulated from each other. An inductor is mounted on the exposed portion and is electrically connected to the two pads.

Abstract: An exemplary power supply system is used to provide one or more operation voltages to a plurality of loads individually. The power supply system includes a timing circuit configured to control a starting time that the corresponding loads start to receive their corresponding operation voltages. The timing circuit includes a first capacitor arranged to be charged by the corresponding DC voltage, and the starting time is determined according to a charging characteristic of the first capacitor.

Abstract: A logical level translator includes a first reference voltage provider, a second reference voltage provider, and a switching circuit. The first reference voltage provider provides a first reference voltage signal with a first logic level to a first connection terminal. The second reference voltage provider provides a second reference voltage signal with a second logic level to a second connection terminal. The switching circuit switches on a connection between the first connection terminal and the second connection terminal when a digital signal input to the first connection terminal or the second connection terminal is a logic high level signal. Then switches off the connection between the first connection terminal and the second connection terminal when the digital signals is a logic low level signal.

Abstract: A power management circuit comprising a power-on signal input, an output terminal a control unit, a switching unit, and a discharge unit. The control unit configured to selectively turn on the switching unit to output a power-on signal to a display module and selectively turn off the switching unit to cut off an electrical connection between the power-on signal input and the output terminal. The discharge unit configured to discharge residual electrical charges in the display module when the switching unit is turned off.