| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce consumption power when a power supply of a computer is off. SOLUTION: When a power source of a system is designated to turn off, a signal PWR is set as a low level, and the signal is inputted in an input terminal 136 of a change-over circuit 130 and regulators 152-156. Consequently, the regulators are not operated, and a power source of a computer is cut off. When the low level signal PWR is inputted, the photocoupler 134 is turned off, a transistor 132 is turned off, and operation of a power-factor improvement circuit is stopped in the change-over circuit 130. As a result, the circuit for power-factor improvement is not operated when the power supply of the computer is cut off, so that consumption power can be reduced.</p> |
