| 摘要 |
<p>A low-cost, small-sized discharge lamp lighting apparatus wherein an excessive current flowing in a discharge lamp is suppressed to prevent abrasion of the electrodes of the discharge lamp, thereby elongating the life of the discharge lamp. A discharge lamp lighting apparatus (10) includes an input power supply (Vi); a power supply circuit (1); a bridge circuit (4) comprising switching elements (Q1-Q4) for causing a discharge lamp (5) to perform an AC operation; a lighting circuit (6); a control circuit (2) for controlling the power supply circuit (1); and a drive circuit (3) for driving the bridge circuit (4). An excessive current suppressing circuit (7), which comprises a resistor element (R1) and a switching element (Q6) connected in parallel to the resistor element (R1), is connected between the negative polarity side of the bridge circuit (4) and the negative polarity side of the power supply circuit (1). This excessive current suppressing circuit (7) automatically can adjust the current flowing in the switching elements (Q2,Q4) to suppress the excessive current at the activation of the discharge lamp (5).</p> |
