| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently reduce power consumption of an AC adapter when the AC adapter is left operating while the AC adapter is not connected with an external apparatus. SOLUTION: When an electronic apparatus (external apparatus) is connected to the AC adapter, and the electronic apparatus is in a standby state, a switching element Q1 repeats on/off-operations between the rated output voltage and the lowest output voltage which can be permitted by the electronic apparatus. Alternatively, when the AC adapter is not connected to the electronic apparatus, voltages detected by an operation amplifier IC1 and resistors R1, R2 and R4 are switched to a voltage lower than the lowest output voltage which can be permitted by the electronic apparatus from the lowest output voltage which can be permitted by the electronic apparatus due to an effect that the resistors R1, R2 are not connected to resistors R8, R9, respectively, in parallel therewith. By this arrangement, when the electronic apparatus is in a non-connection state, the switching element Q1 repeats the on/off-operations between the rated output voltage and the voltage lower than the lowest output voltages which can be permitted by the electronic apparatus. COPYRIGHT: (C)2011,JPO&INPIT |
