| 摘要 |
PURPOSE:To restart a discharge lamp after replacing the discharge lamp in a hot-line job. CONSTITUTION:A ballast B has a lighting determining circuit J for determining a lighting condition of a discharge lamp and stopping supply of a response voltage to an igniter IGN when it is lighted. A timer circuit TM for stopping supply of the response voltage to the igniter IGN after a lapse of a predetermined time after charging an AC power supply V1 is also provided. A switching element of the igniter IGN for switching action by the response voltage given by the ballast B is composed of switching elements Q211, Q212. For the switching element Q212, that having a lower response voltage than the voltage given through the ballast B in replacing a discharge lamp DL is used. In addition, that having a response voltage more than the one for generating a high voltage pulse for starting the discharge lamp DL is used. A switch element S0 which closes is for a period of starting the discharge lamp DL after the discharge lamp is replaced connected between both ends of the switching element Q211. |
