Abstract: A control circuit for a fan includes a fan controller, a switch controller, and a frequency detector. When a pulse-width modulation (PWM) signal output pin of the fan controller outputs PWM signals, the frequency detector outputs a high level signal, connecting an input pin of the switch controller to an output pin of the switch controller. The fan receives the PWM signal. When the PWM signal output pin of the fan controller does not output PWM signals, the frequency detector outputs a low level signal, such that the output pin of the switch controller does not output any signal. In this state, the fan receives a high level signal through a resistor and a power supply, enabling the fan to continue operating.

Abstract: An expansion circuit for a server system includes a first output terminal, a second output terminal, a switch circuit and a detection circuit. The first output terminal receives a first voltage and providing the first voltage to a first hard disk drive group. The second output terminal receives the first voltage and provides the first voltage to a second hard disk drive group. The switch circuit is connected between the first and the second output terminals. The detection circuit detects a number of the at least one server which is electrically connected to the expansion circuit. When two servers are electrically connected to the expansion circuit, the detection circuit switches off the switch circuit. When a server is electrically connected to the expansion circuit, the detection circuit switches on the switch circuit.

Abstract: A memory bank of a computer system includes a detection unit for detecting working state of a storage chip and a register chip of the memory bank. The detection unit detects whether the storage chip and the register chip work normally and outputs detection signals to a motherboard of the computer system according to the detection of the storage chip and the register chip. The motherboard performs predetermined operations according to the detection signals, thus indicating the working state of the storage chip and the register chip.

Abstract: An expansion circuit for a server system includes a power input terminal, a first output terminal and a second output terminal. The power input terminal is configured to receive a first voltage. The first output terminal is configured to receive the first voltage from the power input terminal and provide the first voltage to a first hard disk drive group of the server system. The second output terminal is configured to receive the first voltage from the power input terminal and provide the first voltage to a second hard disk drive group of the server system when the first hard disk drive group and the second hard disk drive group are controlled by a same server.

Abstract: A hard disk of a computer system includes a platter, a spindle motor, a magnetic head, a cache, an interface for connections, and a main control chip. The main control chip within the hard disk detects whether or not each of the cache, the platter, the spindle motor, and the magnetic head are individually working normally. When any of the cache, the platter, the spindle motor, and the magnetic head is not working normally, the main control chip outputs a signal accordingly to an external device connected to the interface.

Abstract: A fan control circuit of a computer includes a fan interface connected to a connector of a fan, a fan controller, a NOT gate, and an electronic switch. The fan controller outputs a PWM signal to the fan interface to control the operation of the fan, and includes a GPIO interface to output a voltage control signal to the NOT gate to switch the electronic switch on or off. A signal output of the electronic switch is connected to the fan interface. The voltage control signal is high level at the start up moment of the computer, and thus does not turn on the fan via the electronic switch. After a preset delay period, the voltage control signal is turned low by the fan controller so that the fan interface receives the PWM signal.

Abstract: A power supply circuit for a hard disk backplane includes a first power input terminal, a second power input terminal, a first switch circuit, and a control voltage output terminal. The first and second power input terminals are configured to receive a first voltage and output the first voltage to supply power to a first hard disk drive group and a second hard disk drive group. The first switch circuit is coupled between the first power input terminal and the second power input terminal. The control voltage output terminal receives a control voltage to switch on or switch off the first switch circuit. When the first switch circuit is switched on, the first power input terminal is electronically connected to the second power input terminal, and when the first switch circuit is switched off, the first power input terminal is disconnected from the second power input terminal.

Abstract: A power supply assembly includes an enclosure, a power supply, an adapter board, a mother board, and an adapter card. The power supply includes a power supply body and an inserting terminal. The adapter board includes an adapter board body, a connecting terminal, and a first inserting head extending from the adapter board body. The inserting terminal is inserted in the connecting terminal. The mother board includes a mother board body and a second inserting head. The mother board body is substantially parallel to the adapter board body. The adapter card includes an adapter card body and two connectors extending from the adapter card body. The two connectors are electronically connected to the first inserting head and the second inserting head. The adapter card body is substantially perpendicular to the mother board body and the adapter board body.

Abstract: A memory bank for a computer system includes a state indication unit for indicating the working state of the memory bank. A register chip of the memory bank includes a detection module that detects whether the memory bank works normally or not and generates a control signal for controlling the indication unit. The indication unit connects to the detection module to receive the control signal and indicates whether or not the memory bank works normally using a light indicator.

Abstract: A power supply circuit includes a main control circuit and a number of switching control circuits. The main control circuit receives working status signals from hard disk drives (HDDs), and outputs control signals according to the working status signals. Each switching control circuit is connected between a power supply unit and a HDD connector for connecting to one of the HDDs. The switching control circuit reconnects or disconnects power to or from the HDD connector according to the control signals.

Abstract: A power supply circuit includes a first power input terminal, a second power input terminal, a first switch circuit, and a first switch controller. The first and second power input terminals are configured to receive a first voltage and output the first voltage to supply a first hard disk group and a second hard disk group. The first switch circuit is coupled between the first power input terminal and the second power input terminal. The first switch controller switches on or switches off the first switch circuit. When the first switch circuit is switched on, the first power input terminal is connected to the second power input terminal. When the first switch circuit is switched off, the first power input terminal is disconnected from the second power input terminal.

Abstract: An unlocking apparatus for printed circuit board, configured for detaching a circuit board, includes a clipping structure secured to the circuit board, two unlocking structures and a chassis. The chassis includes bracket for mounted the circuit board. Each of the two unlocking structures includes a dragging member, a rotating member, a sliding member and a supporting member. The pulling rod is slidably installed on the chassis. One end of the rotating member is rotatably secured to the dragging member, the other end is rotatably secured to the supporting member. The supporting member is mounted to the chassis. The dragging member is moved to drive the sliding member to slide on the supporting member along a second direction which is substantially perpendicular to the bracket, and the clipping structure is slid along with the supporting member to drive the printed circuit board to slide along the second direction.

Abstract: Atest circuit includes a test unit and a converting unit. The test unit includes a first connector connected to a power supply unit, a second connector connected to a motherboard, a sensing resistor, a controller, and an electronic switch. Two input pins of the controller are connected to two ends of the sensing resistor. A first terminal of the electronic switch is connected to the first connector through the sensing resistor. A second terminal of the electronic switch is connected to a control pin of the controller. A third terminal of the electronic switch is connected to the second connector. The converting unit includes a third connector connected to a monitoring device and a converter. Two input pins of the converter are connected to two output pins of the controller. Two data pins of the converter are connected to the third connector.

Abstract: A power supply circuit for powering first and second groups of hard disk drives in a cabinet, includes a connector and first to third connection units. When there is only one server in the cabinet, the first node is connected to the first power terminal of the connector, the first connection unit is turned on, and the second connection unit is turned off. When there are two servers in the cabinet, the first and second nodes are respectively connected to the first and second power terminals of the connector, the first connection unit is turned on, and the second and third connection units are turned off.

Abstract: A heat dissipating system includes a shell, a main circuit board, at least two heat generating elements, and at least one fan. The shell includes a first sidewall, a second sidewall facing the first sidewall, and a third sidewall connected to the first sidewall and the second sidewall. The at least one fan are arranged on the first sidewall. The second sidewall defines a number of vents. The main circuit board is positioned between the at least one fan and the vents. The heat dissipating system further includes a connection assembly positioned between the first and second circuit boards. The main circuit board includes a first circuit board and a second circuit board. The first circuit board is electrically connected to the second circuit board through the connection assembly. The at least two heat generating elements are respectively positioned on the first circuit board and the second circuit board.

Abstract: A power supply management system includes a number of motherboards, a number of power supply units (PSUs), a number of sampling units, and a processor. Each sampling unit is being coupled between a motherboard and a PSU, and outputting a signal as to a normal or abnormal power supply. Thus in the event of a PSU malfunction, the processor identifies the motherboard which is consuming the greatest amount of power, and outputs an alarm to the identified motherboard to reduce the level of power being consumed by that motherboard.

Abstract: A management system includes two motherboards assigned with different identities, a complex programmable logic device (CPLD), and a switch unit. Each motherboard includes a baseboard management controller (BMC) employed to receive a control signal from a client. The BMC outputs an operation signal corresponding to the control signal and an identity of the motherboard. The CPLD is configured to store the control signal and the identity as a record in a priority list, and determine whether the priority list is a void list. The CPLD outputs a switch signal according to the identity of the record obtained from the priority list in response to the priority list not being a void list. The switch unit is configured to receive the switch signal from the CPLD, and enable a power supply unit to power the corresponding motherboard.

Abstract: A memory includes a data pin, an address pin, and a reference voltage generation circuit. The reference voltage generation circuit includes a first reference voltage generation circuit and a second reference voltage generation circuit. The first reference voltage generation circuit is electronically connected to the data pin, and supplies a reliable first reference voltage to the data pin. The second reference voltage generation circuit is electronically connected to the address pin, and supplies a reliable second reference voltage to the address pin.

Abstract: An indication circuit includes a control unit, a decode unit, and a display unit. The control unit is configured to obtain a transfer rate of a hard disk drive (HDD) from a power on self test (POST) code transmitted by a basic input-output system (BIOS) chip, and transmit a rate signal corresponding to the transfer rate of the HDD. The decode unit is configured to decode the rate signal to obtain the transfer rate, and output a decode signal corresponding to the transfer rate. The display unit is configured to display the transfer rate.

Abstract: A motherboard assembly includes a motherboard with a memory slot, an adapter board, and a serial advanced technology attachment dual-in-line memory module (SATA DIMM) with a circuit board and a connector. An edge connector is set on a bottom edge of the circuit board. The adapter board includes a SATA interface, a hard disk drive (HDD) signal multiplier, a power interface, and an expansion SATA interface. The edge connector is connected to the memory slot and the connector is connected to the expansion SATA interface, to enable the motherboard communication with SATA DIMM modules, which are connected to the memory slots.