Abstract: A device to control a 3-phase motor having an inverter connected to each phase terminal and a brake to arrest the 3-phase motor, includes a power supply to supply power to the brake and the inverter at the same time based on a predetermined synchronization signal. The device also includes a control unit to output an inverter control signal to control the inverter and a power control signal to enable the power supply to supply the power to the brake and the inverter. Thus, the device to control a 3-phase motor has an immediate response to a control signal with a reduced production cost and a system size, by reducing circuit components such as a brake relay and a brake power supply.

Abstract: A device to control a 3-phase motor having an inverter connected to each phase terminal and a brake to arrest the 3-phase motor, includes a power supply to supply power to the brake and the inverter at the same time based on a predetermined synchronization signal. The device also includes a control unit to output an inverter control signal to control the inverter and a power control signal to enable the power supply to supply the power to the brake and the inverter. Thus, the device to control a 3-phase motor has an immediate response to a control signal with a reduced production cost and a system size, by reducing circuit components such as a brake relay and a brake power supply.

Abstract: An inverter control apparatus and method of a three-phase motor includes disposing three maximum phase voltage vectors each having an equivalent angle interval corresponding to maximum values of each phase voltage; setting maximum phase voltage vector regions by predetermined angles with respect to each of the maximum phase voltage vectors; setting minimum phase voltage vectors corresponding to the maximum phase voltage vectors in between the maximum phase voltage vector regions; obtaining a desirable voltage by turning on a first switch and turning off a second switch, both connected to the phase terminal of a corresponding maximum phase voltage in each maximum phase voltage vector region; and changing a duty ratio of control signals with respect to other two switches corresponding to the other two phase voltages.

Abstract: A motor power supply including a DC supply part having a pair of supply terminals; an inverter having a pair of connection terminals respectively connected to the supply terminals thereof to receive DC power therefrom and to supply AC power to a motor, a breaking resistor and a control switching element disposed in parallel in an additional line connecting the pair of connection terminals to each other, a control switching element disposed with the breaking resistor in the additional line, a breaking switch disposed to one of the connection terminals and switched to either a normal position or a breaking position connecting the one connection terminal to a corresponding supply part or to the additional line, a speed detector detecting a motor speed and a control part controlling the breaking switch to switch to the breaking position and controlling the control switching element so that an on-off interval of the control switching element is controllable depending on the detected speed

Abstract: A motor power supply having an inrush current protection mode, a motor drive mode, an overvoltage protection mode, and a dynamic braking mode. In the inrush protection mode, a first resistance limits an inrush current to a capacitor which smoothes a rectifier output to provide DC power to an inverter during the motor drive mode. In the overvoltage protection mode, the first resistance is used in conjunction with a switching element to controllably discharge an overvoltage which may occur across the capacitor due to regenerated energy from the motor passing back through the inverter. During the drive mode, the inverter input is connected with the DC power and during the dynamic braking mode, the inverter input is connected with a second resistance which dissipates the energy regenerated by the motor. A controller controls a multi-contact relay and the switching element to implement the various modes of operation.

Abstract: A motor control apparatus supplying AC power to a motor having a plurality of motor windings having an inverting part including a bridge circuit having a plurality of switching units, and supplying the AC power to the motor; brake relays short circuiting the motor windings by turning on when the motor brakes; brake resistors, respectively, connected to the motor windings and consuming an overcurrent generated from the motor when the brake relays short circuit the motor windings; and a switching controller turning on and turning off the switching units provided in one of opposite ends of the inverting part so that the overcurrent consumed by the brake resistors is changeable in proportion to a rotation speed of the motor, when the brake relays short circuit the motor windings to improve an effect of a dynamic braking operation and to prevent breakdown thereof.

Abstract: A power supply having a rectifying circuit rectifying AC power; an inverting part inverting the power rectified and supplying the inverted AC power to a load, and including first and second bridges connected to ends of the rectifying circuit and having respective pairs of switching units serially connected to each other, comprising: a control voltage signal generating part outputting a control voltage signal having values corresponding to positive and negative values to control the AC power supplied from the inverting part to the load; a switching controller controlling, when the control voltage signal is determined to correspond to positive values, one of the switching units of the first bridge to turn off and a remaining one of the switching units thereof to turn on, and controlling the switching units of the second bridge to alternately turn on and turn off corresponding to which one of an absolute value of the control voltage signal and of a predetermined comparison voltage signal is greater.

Abstract: A motor control apparatus supplying braking power to brake a motor comprises a braking power providing unit to receive input power having an input power voltage lower than a braking power voltage and to boost the input power voltage up to the braking power voltage to brake the motor; a switching unit closing to allow the braking power providing unit to store the input power and opening to allow the braking power providing unit to output the braking power by boosting the input power voltage and a stored power voltage up to the braking power voltage; and a controller to control the switching unit to close and to open. With this configuration, a motor control apparatus is provided, in which an additional braking power supply supplying braking power to brake a motor is not needed, thereby decreasing a production cost and a size of a product.

Abstract: A motor power supply including a DC power supply having a pair of power output terminals, and an inverter having a pair of connection terminals connected to the power output terminals of the DC power supply through a pair of power lines, converting power from the DC power supply to supply the converted power to a motor having a plurality of power input terminals, the motor power supply including a braking resistor provided in an additional line connecting the connection terminals with each other; a switching part provided at one of the connection terminals, and selectively connecting the one of the connection terminals with the power output terminal corresponding to the one of the connection terminals, or with the additional line; and a controller controlling the switching part. Components common to both a dynamic braking circuit and the inverter decrease the total size and cost of the motor supply power.

Abstract: A power supply device for inverting power to be supplied to a motor and a method of controlling the power supply device. The power supply device includes an inrush protection (IP) circuit, a power factor correction (PFC) circuit and an overvoltage protection (OP) circuit. A controller and a pair of relays selectively connect predetermined components so that at least one component is selectively changed from operation in one of the IP, PFC and OP circuits to operation in another of the IP, PFC and OP circuits in response to a detected value of an inverter input voltage. The inrush protection circuit operates in a start up mode; the PFC circuit operates while normally driving the motor; and the overvoltage protection circuit operates where the inverter input voltage increases due to regeneration by the motor.

Abstract: A device for inrush current prevention and dynamic braking in a motor having a plurality of power inputting terminals, comprises a diode rectifying unit rectifying power supplied from an AC power supplying unit; a capacitor smoothing the power rectified by the diode rectifying unit; a resistor disposed between the AC power supplying unit and the capacitor, being connected to the capacitor; an inverter connected to terminals of the capacitor and the power inputting terminals of the motor, inverting the power from the capacitor into an AC power having multiple phases and supplying the AC power having multiple phases to the motor; a dynamic braking circuit short-circuiting the power input terminals of the motor; and a relaying unit including a first node connecting the dynamic braking circuit to the resistor and a second node connecting the diode rectifying unit to the capacitor in parallel.

Abstract: A heat dissipation system for a semiconductor device having a plurality of semiconductor chips, includes a heat dissipation member which cools the semiconductor chips, an exterior heat dissipation member which is provided opposite to the heat dissipation member, engaged to the semiconductor device and connected to an electrical ground, an electric conductor member which is provided between the heat dissipation member and the exterior heat dissipation member, and electrically connects the heat dissipation member and the exterior heat dissipation member to each other, and a thermal conductivity insulating member which is inserted between the heat dissipation member and the exterior heat dissipation member. Accordingly, the resistance against common mode noise is increased. Furthermore, the heat dissipation efficiency of the semiconductor device is also increased. The head dissipation system improves the heat dissipation efficiency of the semiconductor device to control noise.

Abstract: A motor power supply for and a method of operating a poly-phase AC motor with power provided from an AC power source through a DC-conversion circuit and an inverter. An output voltage of the DC-conversion circuit is sensed and a controller controls an inrush current limiting resistance to be selectively bypassed according to a first value of the output voltage and controls a pair of switches in an overvoltage protection circuit to return energy stored in the DC-conversion circuit to the AC power source according to second and third values of the output voltage. An operation of the switches is synchronously controlled according to a phase of the AC power source. The overvoltage protection circuit eliminates an overvoltage in the DC-conversion circuit due to energy regenerated by the motor and passed through the inverter to the DC-conversion circuit.

Abstract: A power supply apparatus for a motor including an AC power supply, a diode rectifier circuit to rectify power of the AC power supply and a DC capacitor to smooth the rectified power, comprising a current limiting part provided between the AC power supply and the DC capacitor; a connection switching part to switch a connection state of the diode rectifier circuit and the current limiting part; a controller to control the connection switching part so that the diode rectifier circuit and the current limiting part are connected to each other one of in parallel and in series. Thus, an inrush current protection circuit and an over voltage protection circuit use a single resistor according to their respective functions.

Abstract: The present invention is disclosed a piezoelectric transformer with multiple outputs for lighting a plurality of cold cathode fluorescent lamps at the same time by forming a plurality of output electrodes as one body and a stabilizer having the piezoelectric transformer with multiple output electrodes. The piezoelectric transformer includes a piezoelectric plate; an input electrode formed on an upper surface of the plate; a plurality of output electrodes having an identical band shape, arranged in equal distance in the longitudinal direction of the plate at an outer side of the input electrode, and connected electrically to one ends of the plurality of the cold cathode fluorescent lamps respectively; and a common electrode formed on a bottom surface of the plate, confronting to the input electrode, commonly connected to ground of the stabilizer and other ends of the plurality of the cold cathode fluorescent lamps.

Abstract: A piezoelectric transformer with multiple outputs and a stabilizer having the piezoelectric transformer with multiple output electrodes is disclosed. The piezoelectric transformer with multiple outputs lights a plurality of cold cathode fluorescent lamps at the same time by forming a plurality of output electrodes as one body. The piezoelectric transformer includes a piezoelectric plate; an input electrode formed on an upper surface of the plate; a plurality of output electrodes having an identical band shape, arranged in equal distance in the longitudinal direction of the plate at an outer side of the input electrode, and connected electrically to one ends of the plurality of the cold cathode fluorescent lamps respectively; and a common electrode formed on a bottom surface of the plate, confronting to the input electrode, commonly connected to ground of the stabilizer and other ends of the plurality of the cold cathode fluorescent lamps.

Abstract: A piezoelectric transformer with multiple outputs comprises a piezoelectric plate, a first input electrode being formed on the top surface of the piezoelectric plate, a second input electrode being formed on the bottom surface of the piezoelectric plate, a plurality of first output electrodes being electrically isolated from each other, being formed on the equally divided remaining portions of the top surface of the plate along a diagonal line, and a second output electrode formed on the remaining portions of the bottom surface of the plate, thereby providing a stabilizer for lighting lamps without a ballast capacitor by supplying a regular voltage to more than two fluorescent lamps.

Abstract: The present invention is disclosed a piezoelectric transformer with multiple outputs for lighting a plurality of cold cathode fluorescent lamps at the same time by forming a plurality of output electrodes as one body and a stabilizer having the piezoelectric transformer with multiple output electrodes. The piezoelectric transformer includes a piezoelectric plate; an input electrode formed on an upper surface of the plate; a plurality of output electrodes having an identical band shape, arranged in equal distance in the longitudinal direction of the plate at an outer side of the input electrode, and connected electrically to one ends of the plurality of the cold cathode fluorescent lamps respectively; and a common electrode formed on a bottom surface of the plate, confronting to the input electrode, commonly connected to ground of the stabilizer and other ends of the plurality of the cold cathode fluorescent lamps.

Abstract: The present invention relates to piezoelectric transformers, and more particularly to a piezoelectric transformer with multiple outputs supplying stable voltages into a plurality of fluorescent lamps by connecting it to a plurality of fluorescent lamps.

Abstract: The present invention is disclosed a piezoelectric transformer with multiple outputs for lighting a plurality of cold cathode fluorescent lamps at the same time by forming a plurality of output electrodes as one body and a stabilizer having the piezoelectric transformer with multiple output electrodes. The piezoelectric transformer includes a piezoelectric plate; an input electrode formed on an upper surface of the plate; a plurality of output electrodes having an identical band shape, arranged in equal distance in the longitudinal direction of the plate at an outer side of the input electrode, and connected electrically to one ends of the plurality of the cold cathode fluorescent lamps respectively; and a common electrode formed on a bottom surface of the plate, confronting to the input electrode, commonly connected to ground of the stabilizer and other ends of the plurality of the cold cathode fluorescent lamps.