| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power supply device which achieves a function preventing breakage accidents due to the deterioration of an electrolytic capacitor from occurring by adding a simple circuit and also achieves low cost and space saving.SOLUTION: A switching power supply device includes: a transformer having a primary coil, a secondary coil, and a tertiary coil; a primary side rectification circuit converting alternating current power into direct current power; a primary side electrolytic capacitor smoothing the direct current power; a secondary side rectification circuit converting the alternating current power output from the secondary coil of the transformer into the direct current power; a secondary side electrolytic capacitor smoothing the direct current power; a switching circuit repeatedly opening and closing the primary coil; a pulse width control circuit controlling a pulse width of a drive signal controlling the opening and the closing; a primary side electrolytic capacitor deterioration detection circuit detecting the deterioration of the primary side electrolytic capacitor; and a stop signal generation circuit inputting a deterioration detection signal of the primary side electrolytic capacitor deterioration detection circuit. The operation of a switching power supply circuit is stopped by the deterioration detection signal of the primary side electrolytic capacitor deterioration detection circuit. |
