| 摘要 |
PURPOSE: To prevent a grounding electric current from flowing to a grounding accident of a load output line of a discharge lamp lighting device. CONSTITUTION: A closed circuit of DC electric power supply V1 , primary winding N1 of a transformer T1 and a switching element Q1 and a closed circuit of secondary winding N2 of the transformer T1 , a diode D1 , a capactor C1 and a load circuit which is connected to its both ends and whose final load is a discharge lamp DL, are insulated from each other by the transformer T1 . A control means 10A is arranged in this discharge lamp lighting device, and the switching element Q1 is operated so that an electric current flowing in the transformer T1 is put in a boundary condition, and a driving signal of the switching element Q1 is controlled so that an electric power desired value found on the basis of voltage of the DC electric power supply V1 and a duty of the driving signal of the switching element Q1 is supplied to the discharge lamp DL. |
