Abstract: A method can include obtaining a voltage across a first transistor as an obtained voltage. The method can also include multiplying the obtained voltage by a predetermined multiple M to yield a multiplied voltage. The method can further include applying the multiplied voltage to a second transistor, wherein the second transistor is N times smaller than the first transistor. The method can additionally include providing an output current of the second transistor as an M/N scaled estimate of an output current of the first transistor.

Abstract: The semiconductor device is included in the LED driving circuit (current regulator) of driving the LED array (with series-connected number m×parallel-connected number n), and is formed of a plurality (n pieces) of LED driving devices of controlling a current (constant-current driving) flowing in each string. A vertical semiconductor device, for example, a vertical MOSFET is used as the LED driving device. Both of a main device functioning as a constant-current driving device and a subsidiary device functioning as a circuit-breaking switch during dimming are formed inside a chip of the device, which are formed of the vertical semiconductor devices. In a first surface of the device, each source region of the main device and the subsidiary device is formed so as to be insulated from each other through an isolation region.

Abstract: The semiconductor device is included in the LED driving circuit (current regulator) of driving the LED array (with series-connected number m×parallel-connected number n), and is formed of a plurality (n pieces) of LED driving devices of controlling a current (constant-current driving) flowing in each string. A vertical semiconductor device, for example, a vertical MOSFET is used as the LED driving device. Both of a main device functioning as a constant-current driving device and a subsidiary device functioning as a circuit-breaking switch during dimming are formed inside a chip of the device, which are formed of the vertical semiconductor devices. In a first surface of the device, each source region of the main device and the subsidiary device is formed so as to be insulated from each other through an isolation region.

Abstract: Miniaturization of a multiphase type power supply device can be achieved. A power supply control unit in which, for example, a microcontroller unit, a memory unit and an analog controller unit are formed over a single chip, a plurality of PWM-equipped drive units, and a plurality of inductors configure a multiphase power supply. The microcontroller unit outputs clock signals each having a frequency and a phase defined based on a program on the memory unit to the respective PWM-equipped drive units. The analog controller unit detects a difference between a voltage value of a load and a target voltage value acquired via a serial interface and outputs an error amp signal therefrom. Each of the PWM-equipped drive units drives each inductor by a peak current control system using the clock signal and the error amp signal.

Abstract: An emulsion stabilizer is disclosed having a water tolerance value of between more than about 1.0 and equal or less than about 11.0.

Abstract: A printing ink is disclosed containing: an emulsion stabilizer having a water tolerance value of between more than about 1.0 and equal or less than about 11.0 and water as a dispersed phase, wherein said emulsion stabilizer stabilizes the water to form a stabilized emulsion printing ink.

Abstract: A method can include obtaining a voltage across a first transistor as an obtained voltage. The method can also include multiplying the obtained voltage by a predetermined multiple M to yield a multiplied voltage. The method can further include applying the multiplied voltage to a second transistor, wherein the second transistor is N times smaller than the first transistor. The method can additionally include providing an output current of the second transistor as an M/N scaled estimate of an output current of the first transistor.

Abstract: A printed circuit board (120) includes an insulating substrate (120a) on which conductive films (120b) are formed. Semiconductor devices (8) disposed external to the printed circuit board (120) have their leads (24a, 24b, 24c) connected to the conductive films. A flexible portion (30) is formed in the insulating substrate (120a) at a location near the location where the leads (24a, 24b, 24c) are connected to the conductive films (120b).

Abstract: The semiconductor device is included in the LED driving circuit (current regulator) of driving the LED array (with series-connected number m×parallel-connected number n), and is formed of a plurality (n pieces) of LED driving devices of controlling a current (constant-current driving) flowing in each string. A vertical semiconductor device, for example, a vertical MOSFET is used as the LED driving device. Both of a main device functioning as a constant-current driving device and a subsidiary device functioning as a circuit-breaking switch during dimming are formed inside a chip of the device, which are formed of the vertical semiconductor devices. In a first surface of the device, each source region of the main device and the subsidiary device is formed so as to be insulated from each other through an isolation region.

Abstract: A power supply unit includes an input-side rectifying circuit (4), an inverter (8) and an output-side rectifying circuit (12), which include power semiconductor devices. The power supply unit is powered during a powering period, and the powering is interrupted during a pausing period. The powering and pausing periods alternate. A fan (18) is driven during each powering period to cool the power semiconductor devices. A temperature detector (30) measures the temperature of the power semiconductor devices and develops a measured-temperature representative signal. A setter (38) produces a reference value, which decreases over the pausing period from the measured-temperature representative signal at the beginning of the pausing period to an intended-temperature representative signal representing the temperature to be attained by the power semiconductor devices at the end of the pausing period.

Abstract: A rectifying circuit (18) converts inputted AC power to DC power. An inverter circuit (22) converts the DC power to high-frequency power in accordance with a switching control signal applied thereto from a control circuit (50). A voltage transformer (24) voltage-transforms the voltage of the high-frequency power. An output-side rectifying circuit (40) rectifies the voltage-transformed power. An output detecting circuit (34) detects the magnitude of the voltage of the rectified power, and a signal representative of the detected voltage is applied to the control circuit (50). The control circuit (50) generates such a switching control signal as to make the rectified power have a predetermined value. The value of the voltage from the rectifying circuit (18) is detected by an input detecting circuit (62), and a signal representative of the detected voltage is applied to the control circuit (50).

Abstract: A printed circuit board (120) includes an insulating substrate (120a) on which conductive films (120b) are formed. Semiconductor devices (8) disposed external to the printed circuit board (120) have their leads (24a, 24b, 24c) connected to the conductive films. A flexible portion (30) is formed in the insulating substrate (120a) at a location near the location where the leads (24a, 24b, 24c) are connected to the conductive films (120b).

Abstract: The power supply device of the present invention which outputs pulsed electrical current includes an inverter which converts an input voltage to high frequency AC, a rectifier which rectifies the output of the inverter and converts it to DC, and an output polarity changeover unit which, via a reactor, alternatingly turns ON and OFF the output at a positive electrode side of the rectifier and the output at a negative electrode side thereof. Moreover, this power supply device includes a current transformer including a closed magnetic circuit or coil, pierced by a first output current line in which the current at the positive electrode flows, and by a second output current line in which the current at the negative electrode flows. The directions of piercing of the output current lines through the current transformer are set so that the directions in the current transformer, in which current flows in the first and second output current lines, are the same.

Abstract: A welder power supply apparatus (10) includes an inverter (20), which is driven intermittently when an electrode (34) and a workpiece (36) are separated from each other and no arc is being generated between them, whereby power loss generated in the inverter (20) when the inverter (20) is driven in the non-load state of the power supply apparatus and power loss caused by exciting current flowing through an transformer (24) disposed in the output of the inverter (20) can be reduced. The inverter (20) is driven continuously when output current (Io) becomes higher than a threshold value (Ib) after the electrode (34) and the workpiece (36) are brought into contact with each other for starting arcing between them. In this manner, the arcing can be initiated without fail.

Abstract: Welding conditions are set for a power supply apparatus for use with a welding machine, using a control panel unit (96). A memory (105) stores therein welding conditions as set through the control unit (96), and holds the set welding conditions after turning off of a main power supply switch (1) of the power supply apparatus. Upon turning on of the main power switch (1) for starting welding, the welding conditions stored and held in the memory (105) are read out and set in the power supply apparatus.

Abstract: An emulsion stabilizer is disclosed having a water tolerance value of between more than about 1.0 and equal or less than about 11.0.

Abstract: A printing ink is disclosed containing: an emulsion stabilizer having a water tolerance value of between more than about 1.0 and equal or less than about 11.0 and water as a dispersed phase, wherein said emulsion stabilizer stabilizes the water to form a stabilized emulsion printing ink.

Abstract: One of a plurality of voltages is adapted to be applied to power supply terminals (2a, 2b, 2c). A rectifying circuit (6) rectifies the applied voltage and develops a rectified voltage between the output terminals (6a, 6b) thereof. Inverters (16a, 16b) are connected into one of a plurality of inverter connections between the rectifier output terminals (6a, 6b) in response to one of a plurality of inverter connection indicative signals. The inverter connections are set to correspond to respective ones of the plurality of voltages, so that a predetermined voltage can be applied to each inverter whichever one of the plurality of voltages is applied to the power supply terminals. An inverter connection indicative signal generating circuit (34) is manually operated to generate a desired one of the inverter connection indicative signals. A thyristor (8) is disposed between the rectifier output terminals (6a, 6b) and the inverters (16a, 16b).

Abstract: A welder power supply apparatus (10) includes an inverter (20), which is driven intermittently when an electrode (34) and a workpiece (36) are separated from each other and no arc is being generated between them, whereby power loss generated in the inverter (20) when the inverter (20) is driven in the non-load state of the power supply apparatus and power loss caused by exciting current flowing through an transformer (24) disposed in the output of the inverter (20) can be reduced. The inverter (20) is driven continuously when output current (Io) becomes higher than a threshold value (Ib) after the electrode (34) and the workpiece (36) are brought into contact with each other for starting arcing between them.

Abstract: A heat-generating component cooling structure includes a hollow heat sink having a portion made of a thermally conductive material. The heat sink has an interior path extending from first to second ends of the heat sink. A fan device is disposed at the first end of the heat sink and is adapted to cause air to flow through the interior path. Fins are disposed in the path in the heat sink. Heat-generating components of an electrical circuit are mounted on an outer surface of the heat sink.