| 摘要 |
PROBLEM TO BE SOLVED: To miniaturize a power supply unit and reduce its cost by suppressing the variation of an output voltage small without using a current transformer and a shunt resistor. SOLUTION: The power supply unit is provided with an error amplifier 13 for outputting a signal proportional to a difference between a voltage value obtained by dividing an output voltage at an intermediate point between a first resistor 10 connected to the positive side of the output voltage and a second resistor 11 connected to the negative side of the output voltage, and a command value; and a controller 15 for ensuring that the output voltage may be an output voltage following the command value by giving an output signal of the error amplifier 13 to a switching element 16. With this configuration, a gain of the error amplifier 13 can be controlled in accordance with the output voltage. COPYRIGHT: (C)2009,JPO&INPIT
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