| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power device which can cope with an abnormal state of electronic equipment by providing a mode detection circuit for detecting a burst state in a standby mode and a pulse width of a switching voltage and capturing into a micro-computer a signal detected by the mode detection circuit, in the switching power device used by the electronic equipment which is set to a regular mode for a load control operation and set to a standby mode for suspension of the load control operation in an energizing state all day. SOLUTION: Only in the standby mode, the micro-computer 14 is made to output a standby mode signal, allowing a switching circuit to output a switching pulse of a specified frequency at every constant cycle for a prescribed period. The mode detection circuit 8 is provided for detecting the pulse width of the switching voltage output from a secondary winding to determine whether the operation mode is set to the regular mode or the standby mode. In the standby mode, when the micro-computer 14 receives a signal detected by the mode detection circuit 8 and discriminates that the operation mode is set to the regular mode, the micro-computer suspends outputting of a load drive signal, determining that the electric equipment is abnormal. COPYRIGHT: (C)2009,JPO&INPIT
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