Abstract: A snubber circuit for decreasing a voltage spike of a buck converter includes a resistor unit, a capacitor unit, a detecting unit, and a control unit. The resistor unit provides multiple groups of resistance values. The capacitor unit provides multiple groups of capacitance values. The detecting unit detects voltage spikes of the buck converter corresponding to each group of resistance values and capacitance values. The control unit selects each group of resistance and capacitance to respectively connect to the buck converter and determines a group of resistance and capacitance corresponding to a lowest voltage spike by comparing the detected voltage spikes with each other.

Abstract: A security system and method for an electronic device include comparing data in a Subscriber Identity Module (SIM) card with data in a virtual SIM card, if the virtual SIM card is not blank. The security system further include determining whether the electronic device has received a command of reporting loss of the SIM card from the network server, if the data in the SIM card is the same as the data in the virtual SIM card. The security method further includes running the electronic device normally if the electronic device has not received the command of reporting loss of the SIM card. If the command of reporting loss is received, a contact list and message of the electronic device are deleted and a calling function of the electronic device is disabled.

Abstract: A voltage regulation device employed in a voltage regulation system is for a motherboard power supply. The voltage regulation device includes a first sampling module, a voltage regulation module, a second sampling module, and a main controller. The first sampling module samples current and voltage signals from a power source through the motherboard power supply. The voltage regulation module outputs adjustable drive voltages for the motherboard power supply controlled by the main controller. The second sampling module samples current and voltage signals of the drive voltages from the motherboard power supply. The main controller receives the current and voltage signals, and converts the current and voltage signals from the first sampling module and the second sampling module to corresponding input power and output power, respectively, and the input power and the output power are calculated to generate conversion efficiencies of each drive voltage.

Abstract: A heat dissipation device positioned in a computer case, includes a fan, a plate positioned between the computer case and the fan, at least one motor contiguous with the fan, a motor driver, a fan driver, at least one temperature sensor sensing the temperature in the computer case, and a controller. The fan defines an air outlet facing the computer case. The plate is slidable relative to the air outlet to open or close the air outlet. The motor is configured for moving the plate. The motor driver is configured for driving the motor to work. The fan driver is configured for driving the fan to rotate. When the sensed temperature is higher than a preset threshold temperature, the controller controls the motor to move the plate from the air outlet, and controls the fan to rotate.

Abstract: A mobile phone includes a fingerprint input unit, a storage unit, a switch unit, and a control unit. The fingerprint input unit is used to read and record fingerprint information of a user, and output the fingerprint information. The storage unit stores a fingerprint mode. The switch unit is connected to a power on/off terminal of the mobile phone. The control unit is used to receive the fingerprint information and compare the received fingerprint information with the stored fingerprint mode. If the received fingerprint information is not consistent with the stored fingerprint mode and the mobile phone is at a power-off state, the control unit outputs a first control signal to control switch unit to keep the mobile phone being at the power-off state.

Abstract: A keyboard includes a number of first keys, a control circuit, a switch circuit, and a second key. The switch circuit includes a number of switches. The second key is connected to first terminals of two switches of the switch circuit via the control circuit. A second terminal of each of the switches is connected to a first key. When a second key is pressed, the control circuit controls the switches corresponding to the pressed second key to be turned on, to activate the first keys which are connected to the switches.

Abstract: A keyboard includes a fingerprint input unit, a storage unit, a switch unit, and a control unit. The fingerprint input unit receives fingerprint information of a user. The storage unit stores a fingerprint model. The control unit is connected to the fingerprint input unit, the storage unit, and the switch unit. The control unit receives the fingerprint information of the user from the fingerprint input unit and compares the received fingerprint information with the fingerprint model stored in the storage unit. If the received fingerprint information is consistent with the fingerprint model, the control unit controls the switch unit to be turned on, to output a control signal to power on a computer connected to the keyboard.

Abstract: A power control system includes a rectifier circuit, a buck circuit, a voltage divider circuit, a control circuit, and a switch circuit. A first terminal of the rectifier circuit is connected to an alternating current (AC) power supply. A second terminal of the rectifier circuit is connected to a first terminal of the buck circuit and a first terminal of the voltage divider circuit. A first terminal of the control circuit is connected to a second terminal of the buck circuit. A second terminal of the control circuit is connected to a second terminal of the voltage divider circuit. A third terminal of the control circuit is connected to the switch circuit. The switch circuit is connected to the AC power supply and an electronic device.

Abstract: An exemplary infrared control system includes an infrared control unit and a computer. The infrared control unit is capable of transmitting an infrared signal. The computer includes an infrared response unit, and the infrared response unit includes an infrared receiving circuit and a control circuit electrically connected to the infrared receiving circuit. The infrared receiving circuit is capable of receiving the infrared signal from the infrared control unit. Accordingly the control circuit is capable of processing the infrared signal from the infrared receiving circuit to generate a corresponding command signal to control the computer to power on/off or reset.

Abstract: A wireless remote control device for controlling an electronic device includes a switch module, a wireless transmission module, a wireless receiving module and a control module. The switch module receives a DC voltage and outputs a first control signal. The wireless transmission module receives the first control signal and encodes the first control signal to output an encoded first control signal. The wireless receiving module receives the encoded first control signal and decodes the encoded first control signal to output a decoded first control signal. The control module receives the decoded first control signal and outputs a second control signal to turn on/off or reset the electronic device.

Abstract: A constant current source, a measurement unit, an indication unit, and a controller are provided. The constant current source is connected to a shell of an electric device and configured to supply a constant current to the shell. The shell is connected to a ground line terminal of a power supply to which the electric device is connected. The measurement unit is configured for measuring a first voltage of the ground line terminal and a voltage between the shell and the ground line terminal. The controller is configured for controlling the indication unit to give warnings either when the first voltage is zero or when the second voltage is higher than a preset value.

Abstract: A heat dissipation device positioned in a computer case, includes a fan, a plate positioned between the computer case and the fan, at least one motor contiguous with the fan, a motor driver, a fan driver, at least one temperature sensor sensing the temperature in the computer case, and a controller. The fan defines an air outlet facing the computer case. The plate is slidable relative to the air outlet to open or close the air outlet. The motor is configured for moving the plate. The motor driver is configured for driving the motor to work. The fan driver is configured for driving the fan to rotate. When the sensed temperature is higher than a preset threshold temperature, the controller controls the motor to move the plate from the air outlet, and controls the fan to rotate.

Abstract: An ON/OFF detection circuit for detecting an electronic device includes a switch circuit, a current sampling circuit, an amplifying circuit, and a control circuit. The switch circuit includes an input terminal connected to a constant voltage source, an output terminal coupled to the electronic device, and a control terminal. The current sampling circuit is connected between the input terminal and the output terminal of the switch circuit, and is configured for sampling current flowing to the electronic device and converting sampled current into sampled voltage. The amplifying circuit is configured for filtering and amplifying the sampled voltage. The control circuit controls the ON and OFF of the electronic device and compares the sampled voltages with a comparison voltage to judge the electronic device is qualify or disqualify.

Abstract: A support frame to support an electronic component of a computer system is provided. The support frame includes four support posts and two pairs of brackets mounted on the support posts. Each bracket includes a bottom surface and two side edges extending from opposite sides of the bottom surface along the same axis. A guide member is slidably mounted between one pair of brackets. The guide member includes a main body and two sliding portions positioned on opposite sides of the main body. A plurality of rolling members is movably mounted between the sliding portion and the corresponding side edges of the at least one pair of brackets. The electronic component is secured to the main body, and generating an amount of roll friction when the electronic component is inserted into or withdrawn from the brackets.

Abstract: A temperature detecting apparatus for adjusting direction of airflow from a fan according to thermal status in an electronic device, includes a detection module, a control module, and a driver module. The detection module detects temperatures of a plurality of position coordinates in the electronic device and converts the detected temperatures and the plurality of position coordinates corresponding to the detected temperatures to first voltage signals. The control module receives the first voltage signals and compares the temperatures of corresponding position coordinates to output a position coordinate of the greatest temperature according to the first voltage signals. The driver module receives the position coordinate of the greatest temperature and directs airflow towards a position having the greatest temperature.

Abstract: A temperature sensing device is configured for sensing a temperature of electrical elements disposed on a printed circuit board (PCB) and includes a fixing frame, two guiding rails, a sliding rail, a temperature sensor, a driving device, and a processor. The fixing frame is configured for framing the PCB. The guiding rails are parallelly disposed on the fixing frame. The sliding rail is perpendicularly and slidably disposed between the two guiding rails. The temperature sensor is movably disposed on the sliding rail and configured for sensing the temperature of the electrical elements. The driving device is configured for driving the sliding rail and the temperature sensor to slide along the guiding rails and the sliding rail correspondingly. The processor is connected with the temperature sensor and the driving device and configured for storing positions of the electrical elements and controlling the driving device based on the stored positions.

Abstract: A power cable is configured for connecting at least one electrical device to a power source. The power cable includes an input terminal, at least one output terminal, a power transmitting wire, a switch, a voltage setting device, a voltage sampling device, a voltage comparing device and a power supply. The power transmitting wire connects the input terminal and the output terminal via the switch. The voltage sampling device is configured for sensing a voltage of the output terminal. The voltage comparing device is configured for comparing a preset voltage stored in the voltage setting device and the sampled voltage sensed by the voltage sampling device to turn on or turn off the switch according to the compared result. The power supply is configured for reducing the voltage of the power source to the rated voltage of the voltage comparing device to power the voltage comparing device.

Abstract: A CPU cooling circuit for a CPU includes a thermoelectric element and a current source circuit. The thermoelectric element includes a first thermoelectric substrate attached to the CPU, a second thermoelectric substrate opposite to the first thermoelectric substrate, a plurality of n-type semiconductor units and p-type semiconductor units alternately sandwiched between the first and the second thermoelectric substrates and electrically connected in series between a positive power supply input and a negative power supply input. The current source circuit is configured for providing driving current to flow through the n-type semiconductor units and the p-type semiconductor units of the thermoelectric element according to a temperature of the CPU.

Abstract: A circuit for alarming abnormal state of a computer fan includes a detection circuit coupled to the computer fan, a controller coupled to the detection circuit and the computer fan, an alarm unit coupled to the controller. The detection circuit detects a power source and a speed control signal received by the computer fan, the controller determines the work state of the computer fan according to the power source, the speed control signal, and a speed signal received from the computer fan and raises an alarm through the alarm unit if the computer fan is not working normally.

Abstract: A monitor includes a main body and a control circuit. The main body includes a display and a shield. The control circuit drives a motor mounted to the main body. The control circuit detects a power status of the main body and controls the motor to rotate in response to the power status of the main body, so as to wrap the shield to uncover the display when the main body powers on, or to cover the display when the main body is idle or powers off.