| 摘要 |
PROBLEM TO BE SOLVED: To obtain a switching power unit which can prevent the occurrence of an unexpected cessation of operation and can prevent the occurrence of trouble in a load by accurately predicting the service life of an electrolytic capacitor. SOLUTION: A switching power unit generates a DC voltage by rectifying and smoothing an AC input and an output voltage Vout by switching, transforming, rectifying, and smoothing the DC voltage and is provided with an electrolytic capacitor C1. The power unit is loaded with a processing program containing a step of measuring the frequency (f) of the AC input, a step of measuring the output voltage Vout an an output current Iout, and a step of measuring a terminal voltage VCP of the capacitor C1. The program also includes a step of converting the measured terminal voltage VCP into a terminal voltage, when the load is a rated one and a step of comparing the converted terminal voltage with the preset initial value of the terminal voltage VCP, and when the compared value becomes a prescribed value or smaller, sending an abnormality informing signal to the outside by discriminating that the capacitance of the capacitor C1 has dropped. |
