| ANPEC ELECTRONICS CORPORATION Patent applications |
| Patent application number | Title | Published |
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| 20090283796 | SEMICONDUCTOR DEVICE AND METHOD FOR FORMING THE SAME - A bipolar high voltage/power semiconductor device having a low voltage terminal and a high voltage terminal is disclosed. The bipolar high voltage/power semiconductor is a vertical insulated gate bipolar transistor with injection efficiency adjustment formed by highly doped n+ islands in a p+ anode layer. The device has a vertical drift region of a first conductivity type and having vertical first and second ends. In one example, a region of the second conductivity type is provided at the second end of the vertical drift region connected directly to the vertical high voltage terminal. In another example, a vertical buffer region of the first conductivity type is provided at the vertical second end of the vertical drift region and a vertical region of a second conductivity type is provided on the other side of the vertical buffer region and connected to the vertical high voltage terminal. A plurality of electrically floating lateral island regions are provided within the vertical drift region at or towards the vertical second end of the vertical drift region, the plurality of electrically floating lateral island regions being of the first conductivity type and being more highly doped than the drift region. | 11-19-2009 |
| 20090231052 | PULSE WIDTH MODULATION STRUCTURE ENABLING REGULATED DUTY CYCLE - A pulse width modulation (PWM) structure enabling regulated duty cycle includes a DC power supply unit, a signal generating unit, a voltage-dividing resistor unit, a reference voltage unit, and a comparing unit. When the DC power supply unit supplies a voltage signal to the voltage-dividing resistor unit, the latter receives the voltage signal and sets voltage levels before sending the voltage signal to the signal generating unit, so that a waveform signal generated by the signal generating unit regulates its voltage levels according to the received voltage signal before sending the waveform signal to the comparing unit. The comparing unit receives and compares the signals from the signal generating unit and the reference voltage unit, and outputs a comparison signal for driving a fan motor to operate, so that the finally output signal is substantially linear and smooth. | 09-17-2009 |
| 20090108786 | Motor protection device and method - A motor protection device includes a detection unit for detecting an operating state of a motor and outputting a detection signal; a reference unit for generating a variable reference signal; a discriminating unit for comparing the detection signal with the variable reference signal to discriminate whether the motor is in an abnormal condition; and a protection unit that receives a result of discrimination from the discriminating unit and limits a driving current for the motor when the motor is in an abnormal condition. The motor protection device is characterized in that the reference unit adjusts the variable reference signal according to a motor rotation detection signal, so that the motor rotation detection signal and the detection signal are used synchronously in discriminating whether the motor is in an abnormal condition, and the motor in an abnormal condition may be doubly protected. | 04-30-2009 |
| 20090096544 | PWM switching direct voltage circuit - The present invention relates to a pulse width modulation switching direct voltage circuit. The PWM circuit comprises a first passive device, a second passive device and a third passive device which they are connected orderly in series, and a fourth passive device which is connected in parallel between the first passive device and the second passive device, wherein the rated value of the fourth passive device is at least three times more than the rated value of the first passive device. Herewith, the voltage-cycle relationship of the PWM circuit becomes linear. Under such a state, the PWM circuit is enabled with good work efficiency. | 04-16-2009 |
| 20080265833 | Driving level control structure eliminating electric noise from motor - A driving level control structure eliminating electric noise from motor includes a drive control unit, a sensing unit, a setting unit, a first comparing unit, and a frequency control unit. The first comparing unit generates a first discriminating signal based on a reference level signal provided by the sensing unit and a preset level signal provided by the setting unit. The frequency control unit generates a second discriminating signal based on the first discriminating signal. The second discriminating signal is set to a specific frequency fallen out of a human ear perceptible frequency range before being sent to the drive control unit for controlling a motor coil unit to on or off as a current limiting operation, so that electric noise from a motor during the current limiting operation thereof is eliminated. | 10-30-2008 |
