| 摘要 |
PROBLEM TO BE SOLVED: To provide with a simple circuit configuration a power supply equipment provided with an abnormality detection circuit which can detect abnormal states of a load accurately. SOLUTION: Between both terminals of a smoothing capacitor CO for smoothing pulsating voltage of a rectifier DB, a series circuit of switching elements Q1, Q2 is connected via a parallel circuit of a capacitor C3 and a diode D2. A primary winding of a transformer T1 is connected between a high potential side output terminal of the rectifier DB and a connection between the switching element Q1 and Q2. A capacitor C4 for cutting DC is connected between one end of a secondary winding of the transformer T1 and a low potential side terminal of the smoothing capacitor CO, and a load circuit 2 having a discharge lamp FL is connected between the other end of the secondary winding and the low potential side terminal of the smoothing capacitor CO. A voltage detection circuit 4 detects the last stage of the service life of the discharge lamp FL, by detecting the DC voltage generated across the capacitor C4. |
