Abstract: A printed circuit board includes a plurality of layers and a via hole. The via hole extends through the plurality of layers. A coated film is coated on the inner wall of the via hole and located between two layers of the plurality of layers which need to be electrically connected.

Abstract: A noise filter circuit includes a first control circuit, a second control circuit, and a central processing unit (CPU). The first control circuit includes a first control terminal and a first output terminal. The second control circuit includes a second control terminal and a second output terminal. The CPU includes a clock signal input terminal electrically coupled to the second output terminal. The first control terminal receives a first voltage signal, the first output terminal being electrically coupled to the second control terminal, and the second control terminal receives a second voltage signal at a first voltage level. The first control circuit detects clock signals received by the CPU, the first control terminal receives a first voltage signal at a first voltage level when there are noise signals in the clock signals. The second output terminal is grounded to filter out the noise signals in the clock signals.

Abstract: A voltage warning system includes a voltage dividing module configured to be coupled to an output voltage from a power module; a first switch module is coupled to the voltage dividing module; a second switch module is coupled to the first switch module; and a warning module is coupled to the second switch module. The voltage dividing module is configured to divide the output voltage, and the divided voltage is configured to switch on and off the first switch module. The first switch module is configured to activate and deactivate the second switch module. The second switch module is configured to activate and deactivate the warning module. When the output voltage is lower than a setting voltage, the divided voltage activates the warning module to sound alarm via the first switch module and the second switch module.

Abstract: An alarm circuit for electronic device includes a detection unit, a signal conversion circuit, and an alarm control circuit. The detection unit is configured to detect a working status of an electronic device, and output a control signal of a first voltage level when the detection circuit determines the presence of smoke in the electronic device. The signal conversion circuit is configured to receive the control signal of the first voltage level, and convert the control signal of the first voltage level to an alarm signal of a first voltage level. The alarm control circuit is configured to receive the alarm signal of the first voltage level and transmit an alarm.

Abstract: An on-screen display (OSD) adjustment system includes a display module, a control module, a touch module, and a switch module. The control module controls the display module to display multimedia files. The switch module includes a first switch unit coupled between the control module and the touch module and a second switch unit which is coupled between the touch module and a host. The control module determines whether user adjustment of the OSD is required and if so switches on the first switch unit and switches off the second switch unit. The touch module is electronically coupled to the control module, such that the control module is capable of receiving operation signals by touching on the touch module, to adjust configurable items of the monitor. An OSD adjustment method is further disclosed.

Abstract: A distance detection system in an electronic device includes a vibration prompt circuit and a prompt module. The vibration prompt circuit includes a distance sensor, a processor, and a comparison module. The distance sensor is coupled to the processor. The processor is coupled to the comparison module. The comparison module is coupled to the prompt module. The distance sensor sends a distance value as to the distance between itself and a detected object to the processor. The processor converts the distance value to a current value and the current value is compared with a reference value. The prompt module activates a vibration device if the current value is greater than the reference value. A vibration prompt circuit and a vibration prompt method are also provided.

Abstract: A detection device detects the integrity of a connection between respective connectors of two devices. The detection device includes a control chip, an electronic switch, and an alarm member. The control chip is connected to the alarm member through the electronic switch. When the detection device works, the control chip is connected to the detection pin of the first connector. When the first connector is properly connected to the second connector, the detection pin outputs a first signal to the control chip causing the electronic switch to be off. When the first connector is connected with the second connector improperly, the detection pin outputs a second signal and the control chip turns on the electronic switch, sounding an alarm.

Abstract: A computer recovery circuit for a computer includes a detection circuit and a recovery control circuit. The detection circuit includes a first control terminal and a first output terminal. The recovery control circuit includes a second control terminal and a second output terminal. The detection circuit is configured to detect a working status of the computer. The first control terminal is configured to receive the first voltage signal of a first voltage level when the computer malfunctions. The first output terminal is configured to output a control signal of a first voltage level to the second output terminal. The second output terminal outputs a recovery signal having a first voltage level to the south bridge chip, thereby causing the computer to restart.

Abstract: A detection device detects the integrity of a connection between respective connectors of two devices. The detection device includes a control chip, an electronic switch, and an alarm member. The control chip is connected to the alarm member through the electronic switch. When the detection device works, the control chip is connected to the detection pin of the first connector. When the first connector is properly connected to the second connector, the detection pin outputs a first signal to the control chip causing the electronic switch to be off. When the first connector is connected with the second connector improperly, the detection pin outputs a second signal and the control chip turns on the electronic switch, sounding an alarm.

Abstract: A central processing unit (CPU) protection circuit for providing power supply for a CPU on a motherboard includes a detection unit, a south bridge chip and a switch circuit. The detection unit includes a first detection terminal and a second detection terminal. The south bridge chip is electrically coupled to the first detection terminal and is configured to detect a detection signal and receive a direct current (DC) voltage via a first resistor. The switch circuit is configured to receive the detection signal, and output a first control signal to the south bridge chip according to the detection signal.

Abstract: A wireless module includes a socket and a wireless plug. The socket is configured to couple to a circuit board. The wireless plug has a coupling unit, a data transmission unit, and a data operation unit. The coupling unit is configured to transfer data between the socket and the data operation unit. The data operation unit is configured to encode data from the coupling unit and decodes data from the data transmission unit. The data transmission unit is configured to send out the encoded data or receive data wirelessly. When the data transmission unit sends out the encoded data, the data is transferred from the socket via the coupling unit and the data operation unit. When the data transmission unit receives data, the received data is transferred to the socket via the data operation unit and the coupling unit.

Abstract: A fan detecting device includes a motherboard, a first direct voltage, and an insert detecting unit. The motherboard includes a fan socket unit. The fan socket unit includes an insert detecting pin. The insert detecting unit includes a detecting terminal. The insert detecting pin is coupled to the first direct voltage and the detecting terminal. When the fan socket unit is void, the detecting terminal receives a high level signal. When the fan socket unit is coupled to a fan connector, the insert detecting pin is grounded; the detecting terminal receives a low level signal.

Abstract: A charging circuit includes a power supply chipset, a charging port, and a detecting circuit. The power supply chipset includes an enable pin. A voltage on the enable pin controls the power supply chipset. The charging port includes a detecting pin which detects whether there is an electronic device connected on the charging port. The detecting circuit is connected between the detecting pin and the enable pin. The detecting circuit controls the voltage on the enable pin to cause the power supply chipset to output a charging voltage to the power supply chipset in event an electronic device that requires charging is connected to the charging port.

Abstract: A connector leakage protection system includes a current foldback module with a first end coupled to an output port of a DC power supply; an anti-interference module with a first end coupled to a second end of the current foldback module, and a second end coupled to a power port of a connector; and a leakage protection module between the output port and the first end of the current foldback module, or the second end of the current foldback module and the first end of the anti-interference module, or the second end of the anti-interference module and the power port. When the output port outputs a DC voltage, the leakage protection module is switched on. When the output port does not output the DC voltage, the leakage protection module is switched off, preventing current leakage from flowing to the output port. A connector leakage protection circuit is also provided.

Abstract: An interface supply circuit includes a power supply unit, a switch unit coupled to the power supply unit, and a control unit coupled to the switch unit. The control unit and the switch unit are configured to couple to an interface. The control unit is configured to output a first control signal in event that a corresponding device is inserted into the interface. The switch unit is configured activate upon receiving the first control signal. The power supply unit is configured to supply power to the interface after the switch unit is activated. The control unit is further configured to output a second control signal in event that no device is inserted into the interface. The switch unit is further configured to be switched off after receiving the second control signal. The power supply unit is configured to be disconnected from the interface in event the switch unit is switched off.

Abstract: A detecting circuit for detecting a signal wire includes a first port, a second port, a control chipset, a transistor, and a LED. The first port is connected to the second port via the signal wire. The first port includes a first display mark bit pin which is configured to connect to ground when a signal wire connects the first port and the second port well. The control chipset includes a control pin and a detecting pin connected to the first display mark bit pin. The transistor is coupled to the control pin and a power source. The LED is connected to a power source via the transistor. The control pin actives the transistor and thereby active the LED, in event the detecting pin detects that the first display mark bit pin is not connected to ground.

Abstract: An interface supply circuit includes a power supply unit, a control unit coupled to the power supply unit, and a detection unit coupled to the control unit. The detection unit is configured to couple to an interface. The detection unit is configured to output a first control signal upon detecting that a device is inserted into the interface and output a second control signal upon detecting that no device is inserted into the interface. The control unit is configured to be switched on upon receiving the first control signal. The power supply unit is configured to supply power to the interface in event that the control unit is switched on. The power supply unit is configured to be disconnected from the interface in event that the control unit receives the second control signal.

Abstract: An interface supply circuit includes a power supply unit, a first and a second control circuit, and a detection unit coupled to an interface. The detection unit is configured to output a first control signal upon detecting a corresponding device is inserted into the interface and output a second control signal upon detecting no device is inserted into the interface. The first control circuit is configured to switch off in event receiving the first control signal and switch on in event receiving the second control signal. The second control circuit is configured to switch on in event the first control circuit is switched off and switch off in event the first control circuit is switched on. The power supply unit is configured to supply power to the interface after the second control circuit is switched on and be disconnected from the interface after the second control circuit is switched off.

Abstract: A power supply system includes a power supply unit, a voltage converting unit, a comparison unit, and a switching unit. The power supply unit is configured to provide working voltage for a motherboard via a first resistor. The voltage converting unit includes a voltage converting chip. The voltage converting chip is configured to detect a first direct current (DC) voltage on the first resistor, and convert the first DC voltage to a second DC voltage. The comparison unit is configured to receive the second DC voltage, compare the second DC voltage with the working voltage, and output a switch signal. The switching unit is configured to receive the switch signal, and output a control signal to a central processing unit (CPU) on the motherboard according to the switch signal. The CPU is configured to adjust its frequency according to the control signal.

Abstract: A DC power supply control system includes a voltage conversion module configured to couple to a DC power supply and convert a DC voltage to a power voltage; a power port coupled to the voltage conversion module and configured to be coupled to a peripheral load; a switch module coupled to the voltage conversion module and configured to switch on/off the voltage conversion module; and a detection module coupled to the power port and configured to detect the peripheral load. When the detection module detects the peripheral load, the switch module switches on the voltage conversion module, allowing the DC voltage to be converted to the power voltage. Without a peripheral load being detected by the detection module, the switch module switches off the voltage conversion module. A DC power supply control circuit is further disclosed.