Abstract: A power supply system for preventing battery packs connected in parallel from charging each other is provided. Each of a plurality of battery packs includes a plurality of batteries, a sensing resistor, a detector circuit, a discharging transistor, a charging transistor, and a controller circuit. The sensing resistor has a first end connected to a negative terminal of the battery packs and a second end connected to a negative electrode of the battery circuit. The detector circuit is connected to the first end and the second end of the sensing resistor. The discharging transistor has a first end connected to a positive terminal of the battery packs and a second end connected to a first end of the charging transistor. According to a current of the sensing resistor, the controller circuit controls the discharging transistor and the charging transistor to be turned on or off.

Abstract: A relay drive circuit electrically connects to an alternating current power source for driving a relay includes a zero crossing test circuit, a logic control circuit, and a switch. The zero crossing test circuit is electrically connected to the alternating current power source and is for obtaining zero crossing regions of the alternating current power source and outputting a corresponding zero crossing detect signal. The logic control circuit is electrically connected to the zero crossing circuit and is capable of receiving the zero crossing detect signal and a corresponding switch control signal. The switch is electrically connected to the logic control circuit and the relay and is switched on or off in the zero crossing regions under the control of an output signal from the logic control circuit to corresponding control and power the relay on or off.

Abstract: A power distribution apparatus includes an outlet board, a fuse board, and at least one connector. The outlet board is connected to the fuse board through the at least one connector.

Abstract: An exemplary over-voltage protection device used in an electronic device includes a housing capable of being grounded, a circuit board, a connecting member detachably attached to the circuit board and the housing to electrically connect the circuit board with the housing, and a protection member connected to the circuit board and circuitry of the electronic device. When an over-voltage is generated in the electronic device, the over-voltage is transmitted to the ground through the protection member, the circuit board, the connecting member, and the housing.

Abstract: An alternating current (AC) power supply measuring circuit includes a voltage dividing circuit, a measuring integrated circuit (IC), a control board, and a first power rectifying circuit. The voltage dividing circuit receives an AC voltage signal and divides the AC voltage signal to a first voltage dividing signal and a second voltage dividing signal. The measuring IC receives the first and second voltage dividing signals to obtain an AC voltage measuring signal. The control board receives the AC voltage measuring signal and processes the AC voltage measuring signal. The first power rectifying circuit provides a floating ground signal to the voltage dividing circuit.

Abstract: A server enclosure includes a power input terminal to receive power signals, a number of connection elements, a number of lead terminals, and a number of power output terminals. Each connection element includes a connection portion and two fixing arms extending from opposite ends of the connection portion. The connection portion is engaged with the power input terminal to receive the power signals and output the power signals to the two fixing arms. Each lead terminal includes a first connection portion fixed to one fixing arm along an extending direction of the fixing arm to receive the power signals and a second connection portion to receive the power signals. Each power output terminal is connected to one of the second connection portions to receive the power signals.

Abstract: A chip adapter used to install a chip on a first chip arranging area of a circuit board includes a board. The size of the board has the same size as the first chip arranging area of the circuit board. Edges of the chip adapter define a number of gaps corresponding to first pads of the circuit board. A second chip arranging area of the same size as the chip is arranged in a center of the chip adapter. A number of second pads are arranged around the second chip arranging area of the chip adapter corresponding to pins of the chip. Each second pad is electrically connected to a sidewall of the corresponding gap of the chip adapter.

Abstract: A power distribution unit includes a communication unit. The communication unit includes a communication port and a protection circuit. The communication unit includes a ground pin and a plurality of signal pins. The ground pin is connected to a digital ground of the power distribution unit. The signal pins are connected together to receive a voltage signal outputted by a hi-pot tester. The protection circuit includes a plurality of resistors connected between the signal pins and an analog ground of the power distribution unit.

Abstract: A voltage protecting circuit includes a switch unit, an upper limited voltage detecting unit, a lower limited voltage detecting unit, and a logic control unit. When a voltage output from a voltage input interface is less than the lower limited voltage or greater than the upper limited voltage, the logic control unit outputs a control signal to turn the switch unit off. The output voltage outputted from the voltage input interface is not provided to a working circuit. When the output voltage outputted from the voltage input interface is greater than the lower limited voltage and less than the upper limited voltage, the logic control unit outputs a control signal to turn the switch unit on. The output voltage output from the voltage input interface is provided to the working circuit.

Abstract: A relay drive circuit electrically connects to an alternating current power source for driving a relay includes a zero crossing test circuit, a logic control circuit, and a switch. The zero crossing test circuit is electrically connected to the alternating current power source and is for obtaining zero crossing regions of the alternating current power source and outputting a corresponding zero crossing detect signal. The logic control circuit is electrically connected to the zero crossing circuit and is capable of receiving the zero crossing detect signal and a corresponding switch control signal. The switch is electrically connected to the logic control circuit and the relay and is switched on or off in the zero crossing regions under the control of an output signal from the logic control circuit to corresponding control and power the relay on or off.

Abstract: A server enclosure includes a power input terminal to receive power signals, a number of connection elements, a number of lead terminals, and a number of power output terminals. Each connection element includes a connection portion and two fixing arms extending from opposite ends of the connection portion. The connection portion is engaged with the power input terminal to receive the power signals and output the power signals to the two fixing arms. Each lead terminal includes a first connection portion fixed to one fixing arm along an extending direction of the fixing arm to receive the power signals and a second connection portion to receive the power signals. Each power output terminal is connected to one of the second connection portions to receive the power signals.

Abstract: An exemplary over-voltage protection device used in an electronic device includes a housing capable of being grounded, a circuit board, a connecting member detachably attached to the circuit board and the housing to electrically connect the circuit board with the housing, and a protection member connected to the circuit board and circuitry of the electronic device. When an over-voltage is generated in the electronic device, the over-voltage is transmitted to the ground through the protection member, the circuit board, the connecting member, and the housing.

Abstract: A power device includes two groups of diodes, a step-down circuit, and a capacitor. Each group of diodes includes a first diode and a second diode. An anode of the first diode is connected to a cathode of the second diode, a node between the first and second diode is connected to one of live lines and neutral lines of at least one alternating current source. The step-down circuit includes a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The first and second input terminals are respectively connected to cathodes of the first diodes and anodes of the second diodes, the first and second output terminals are respectively connected to a power terminal and a ground terminal of a load. Two terminals of the capacitor are respectively connected to the first and second input terminals of the step-down circuit.

Abstract: A power distribution apparatus includes an outlet board, a fuse board, and at least one connector. The outlet board is connected to the fuse board through the at least one connector.

Abstract: A POS terminal comprises a controller, a main display, a sub-display, and a multimedia display. The controller comprises a casing including a top plate. The main display is disposed on the top plate. The sub-display is disposed on the top plate, and the display panel of the sub-display facing substantially back away from the display panel of the main display. The main board comprises a central processing unit (CPU), a south bridge chip (SBC) connected to the CPU, and a north bridge chip (NBC) connected to the CPU. The main display is connected to the NBC. The sub-display is connected to the SBC. The multimedia display is connected with the NBC.

Abstract: An output circuit for audio codec chip includes an audio amplifier chip and a noise eliminating circuit electrically connected to the audio codec chip and the audio amplifier chip. The audio amplifier chip receives audio signals form the audio codec chip and outputs amplified audio signals. The noise eliminating circuit includes a voltage detection circuit and a switch circuit; wherein when the voltage detection circuit detects a high voltage level power on/off signal in the audio signals received by the audio codec chip, the voltage detection circuit turns on the switch circuit. The audio amplifier chip is grounded via the switch circuit for eliminating interference of the noise signals.

Abstract: A power supply driver circuit for providing power to an electronic device includes a switch module, a voltage regulator and a driver module. The switch module receives a control signal and turns on according to the control signal. The voltage regulator receives a first voltage and outputs a second voltage when the switch module turns on. The driver module provides power to the electronic device when the driver module receives the second voltage.

Abstract: A chip adapter used to install a chip on a first chip arranging area of a circuit board includes a board. The size of the board has the same size as the first chip arranging area of the circuit board. Edges of the chip adapter define a number of gaps corresponding to first pads of the circuit board. A second chip arranging area of the same size as the chip is arranged in a center of the chip adapter. A number of second pads are arranged around the second chip arranging area of the chip adapter corresponding to pins of the chip. Each second pad is electrically connected to a sidewall of the corresponding gap of the chip adapter.

Abstract: An electronic device includes a lightning protection circuit, a DC power unit, a housing, and a safety test switching device. The lightning protection circuit includes a circuit board, a fire wire, a ground wire, an AC power unit, and at least two protection elements. Both the fire wire and the ground wire are coupled to the DC power unit and the AC power unit. The housing includes a bottom board. The circuit board is disposed on the bottom board. The safety test switching device includes a conduction block formed on the circuit board and a conductive plug. The conduction block defines a threaded hole. The conductive plug is detachably plugged into the conductive block, when the conductive plug is detached from the conductive block, the lightning protection circuit and the ground are an open circuit.

Abstract: A power supply system for a computer, includes a power supply unit, a DC/DC converter circuit, memory, and a computer boot component. The power supply unit rectifies AC voltage into a first DC voltage. The DC/DC converter circuit is provided with the first DC voltage, and converts the first DC voltage into a plurality of usable DC voltages. The memory is provided with part of the plurality of usable DC voltages directly, and stores power on data which is capable of power on the computer. The computer boot component is provided with part of the plurality of usable DC voltages directly. The computer boot component is triggered to generate a power on signal to revive the power on data from the memory to power on the computer.