Abstract: A power supply circuit includes a load, a chargeable battery, a discharging circuit, a charging circuit, an adapter, and a control circuit. When the adapter operates normally, the control circuit measures a voltage of the chargeable battery, and controls the charging circuit to charge the chargeable battery when the voltage of the chargeable battery is less than a preset value. The control circuit measures a charging current and a temperature of the chargeable battery, and regulates the charging current through the charging circuit according to the measured charging current and temperature. The adapter provides a voltage to the load through the discharging circuit. When the adapter is powered off, the control circuit does not sense a voltage a voltage from the adapter. The control circuit controls the chargeable battery to power the load through the discharging circuit.

Abstract: A control system for a battery includes a battery backup unit (BBU), a switch circuit coupled between the BBU and the adapter, and a complex programmable logic device (CPLD) coupled to the BBU and the switch circuit. The CPLD controls the switch circuit to turn on when an actual rate between a rest voltage and a rated voltage of the battery is less than a predetermined rate, to charge the battery through the switch circuit. If the actual rate is greater than or equal to the predetermined rate, the CPLD maintains the adapter to charge or discharge the battery according to state of the battery.

Abstract: A detection device to detect a power serving time of a super capacitor for a power-disconnected storage card and an amount of the data packets capable of being stored during the detected serving time is provided. The power-disconnected storage card includes a memory. The detection device includes a power supply unit, the super capacitor, a controller, a storage unit, and a detection unit. The storage unit stores the data packets. The detection unit includes a charge notification module, a data notification module and a time module. The charge notification module generates a first notification signal to the time module. The data notification module generates a second notification signal to the time module when the storage unit transmits the data packet to the memory. The time module records time when the memory completely store the data packet according to the first notification signal and the second notification signal.

Abstract: In a method for modularizing power supplies placed on a printed circuit board (PCB) using a computing device, a circuit design drawing of a power supply is obtained from a database. The method acquires circuit design data of the power supply from the circuit design drawing of the power supply, and modularizes the circuit design data to generate a virtual power supply. The method generates a first layout of the virtual power supply on the PCB in a landscape orientation according to a horizontal dimension of the PCB, and generates a second layout of the virtual power supply on the PCB in a portrait orientation according to a vertical dimension of the PCB. A component information system (CIS) management library is created in the database, and the first layout and the second layout of the virtual power supply are stored in the CIS management library.

Abstract: One embodiment of method and apparatus for laminating a first substrate to a second substrate can use a liquid optically clear adhesive to form an initial contact area in addition to bonding the first substrate to the second substrate. When either the first substrate or the second substrate is relatively clear, the initial contact area can help reduce the introduction of bubbles or voids into a lamination region between the two substrates. In another embodiment, selected regions of a substrate can be treated to enhance the flow of the liquid optically clear adhesive, which can also reduce the introduction of bubbles and voids into the lamination region.

Abstract: A buck converter includes a first MOSFET and a second MOSFET connected in series, a PWM module coupled to gates of the first MOSFET and the second MOSFET, and a control unit being coupled to the input current acquired unit, the input voltage acquired unit, the output current acquired unit, the output voltage acquired unit and the PWM module respectively, wherein the control unit controls a switch frequency of the PWM module and acquires the input current, the input voltage, the output current and the output voltage from the input current acquired unit, the input voltage acquired unit, the output current acquired unit and the output voltage acquired unit respectively.

Abstract: A driving voltage adjusting circuit includes a digital rheostat, a control chip, a low dropout regulating circuit, and a driving circuit. The control chip is connected with the digital rheostat, and configured for adjusting the resistance of the digital rheostat. The low dropout regulating circuit is connected with the digital rheostat and outputs an output voltage according to the resistance of the digital rheostat. The driving circuit comprising a number of switch elements connected with each other and a driver configured for driving the switch elements, each of the switch elements comprising a first terminal, a second terminal, and a control terminal configured for controlling connection and disconnection of the first terminal and the second terminal; the first terminal and the second terminal connected with the control chip, the driver is connected with the low dropout regulating circuit and output an driving voltage to the control terminal.

Abstract: An inductance measurement circuit includes a control circuit, a constant current supply circuit, a voltage detecting circuit, and a display circuit. The control circuit controls the constant current supply circuit to supply a first current for a first inductor. The control circuit controls the voltage detecting circuit to detect a voltage on the first inductor. The control circuit obtains an internal resistance of the first inductor by dividing the first voltage by the first constant current. The display circuit displays the internal resistance of the first inductor.

Abstract: Embodiments related to an undervoltage detector are described and depicted. An undervoltage detector is formed to detect a low input bias voltage with a voltage divider network including first and second series circuits of semiconductor devices coupled to terminals of the input bias voltage source, and a resistor voltage divider including first and second voltage divider resistors coupled in series with the first and second series circuits. A ratio representing the numbers of semiconductor devices in the series circuits is substantially equal to a ratio of resistances in the resistor voltage divider. The equality of the ratios may be corrected by the presence of other resistances in the undervoltage detector. The semiconductor devices are each coupled in a diode configuration. The first series circuit is coupled to a current mirror to provide a bias current for a comparator that produces an output signal for the undervoltage detector.

Abstract: A measurement system includes a control circuit, a measurement circuit, and a display circuit. The measurement circuit includes a first capacitor. The control circuit outputs control signals to control first or second inductors and the first capacitor to compose an LC circuit. Inductance can be gained according to the formula: L = 1 4 ? ? · f 2 · C , where L stands for the inductance, f stands for a frequency of the LC circuit, ? stands for ratio of a circle's circumference to its diameter, and C stands for capacitance of the first capacitor. The control circuit also controls the first and second inductors to be connected in parallel and then connected in parallel to the first capacitor to compose an LC circuit, to determine a coupling inductance. A leak inductance is equal to a half of the coupling inductance. The display circuit displays the inductances of the first and second inductors and the leak inductance.

Abstract: A method and system for controlling a motor is provided. In particular, various embodiments of the present disclosure describe a method and system for controlling a spindle motor in a hard disk drive (HDD) A method of controlling a motor is provided, the motor including a 3-phase synchronous motor with three terminals of an electromagnetic winding configuration. The method includes providing an input voltage between two of the terminals and measures a resultant silent terminal voltage at the third terminal, which is thereafter used in determining a rotor position. A corresponding system for controlling a motor is further provided.

Abstract: A measurement circuit includes an instruction input unit, a charging circuit to charge a capacitor, a charging and discharging circuit to control the capacitor to leakage discharge, a control circuit, a first amplifying circuit, and a display unit. The control circuit receives a measurement instruction through the instruction input unit to control the charging circuit to charge the capacitor, and receives a stop charging signal from the charging circuit when a voltage of the capacitor reaches a saturation voltage for controlling the charging circuit to stop charging the capacitor. The first amplifying circuit measures a leakage voltage of the capacitor, amplifies the measured leakage voltage, and outputs the amplified leakage voltage to the control circuit. The display unit displays the leakage voltage of the capacitor.

Abstract: An impedance measuring device for an electronic component includes a constant voltage source, a load supplying circuit, a voltage detection circuit, and a controller. The constant voltage source outputs an input voltage. The load supplying circuit supplies a load resistor that is electronically connected in series with the electronic component between the constant voltage source and ground. The voltage detection circuit detects a voltage across the load resistor. The controller receives the voltage across the load resistor from the voltage detection circuit, and calculates an equivalent impedance of the electronic component according to the input voltage, the voltage across the load resistor, and the resistance of the load resistor.

Abstract: An input power measuring device includes a board with an edge connector, a first dual inline memory modules (DIMM) socket, a resistor, a differential amplifier circuit, a voltage dividing circuit, a display screen, and a controller. When the edge connector is inserted into a second DIMM socket of a motherboard and the motherboard is powered on, the resistor samples first current, and converts the first current into a first voltage. The differential amplifier circuit amplifiers the first current to a second current. The voltage dividing circuit divides the first voltage, and outputs a second voltage. The controller converts the second current into a third current, converts the second voltage into a third voltage, and calculates a power according to the third current and the third voltage.

Abstract: A power sequence circuit includes a control circuit and a plurality of output circuits. The control circuit provides a plurality of power-on signals and a plurality of power-off signals according to a power-on sequence and a power-off sequence. Each of the output circuits provides an output voltage when receiving a corresponding one of the power-on signals, and stops providing the output voltage when receiving a corresponding one of the power-off signals. The power sequence circuit controls the output voltages by the power-on sequence and the power-off sequence.

Abstract: A test device includes a transformer, a loop analyzer, and a protection circuit. The protection circuit includes a control unit, a signal acquisition and amplification unit, and an electronic switch. When the loop analyzer outputs a signal, the signal acquisition and amplification unit acquires the signal output from the loop analyzer, amplifies the acquired signal, and outputs the amplified signal to the control unit. The control unit transforms the received signal from analog form to digital form, and compares the digital signal with a reference value. If the digital signal is greater than the reference value, the control unit outputs a control signal to the electronic switch, to turn off the electronic switch. The signal output from the loop analyzer cannot be transmitted to a buck circuit.

Abstract: A power supply test device includes a function generator, a loading circuit, a current detection circuit, and a controller. The function generator outputs a square-wave signal to the loading circuit. The loading circuit is electronically connected to a power supply, the loading circuit regulates an output current of the power supply according to the square-wave signal. The current detection circuit cooperates with the controller in detecting a slope of the output current. The controller compares the detected slope with a preset value, and regulates the square-wave signal according to the comparison to regulate the slope of the output current.

Abstract: A runout measurement system is proposed for measuring the runout of a moving surface of a device having a rotating body, such as a mass storage device (100) (e.g. a hard disk drive) having a rotor which in use includes a rotating recording medium. A sensor (102) interacting with the moving surface obtains a displacement signal. The displacement signal is sampled by a sampling unit (104) controlled by a unit (109) which initiates sampling based on both a signal indicating a ZCP and the clock signal of a high frequency (e.g. 20 MHz) clock (106). Simultaneously, the same clock (106) is used by a counter 108 to measure the spacing between one or more ZCP times. This permits the correspondence between the sampling times and the angular position of the rotor to be found with a high accuracy which depends upon the clock frequency, and thereby allows calculation of repeatable runout (RRO) and non-repeatable runout (NRRO).

Abstract: A ground test circuit for a power supply unit includes a sampling circuit, a converting circuit, a processing circuit, and a switch circuit. The sampling circuit detects a voltage difference between a first ground terminal and a second ground terminal. The converting circuit converts the voltage difference to a digital value. The processing circuit compares the digital value to a predetermined value. As long as the digital value is smaller than the predetermined value, the switch circuit allows an external power source to be connected to the power supply unit. Thereby, the ground test circuit controls the connection between the external power source and the power supply unit according to the result of comparison of values done by the processing circuit.

Abstract: A measurement card includes a circuit board, an edge connector on a bottom edge of the circuit board, a port arranged on the circuit board, and a single-pole double-throw switch for connecting the port to either a first or a second pin of the edge connector to tests the VDDQ and VTT outputs of a memory slot.