| 摘要 |
<p>PURPOSE: To provide a circuit arrangement with which electrodes of a discharge lamp can be preheated within a short time either the ballast is inductive or capacitive. CONSTITUTION: This circuit arrangement is to preheat electrodes of a discharge lamp LA connected with a ballast VSA in series by a.c. electric voltage. This circuit arrangement comprises a switching element S connected with the lamp LA in parallel and controlled by a control signal. A circuit part II to adjust both of the phase and the frequency of the control signal responding to the types of the ballast; an inductive type or a capacitive type; is installed in the circuit arrangement. Either an inductive ballast is used or a capacitive ballast is used, the electrodes of the lamp can be preheated within a short time by the circuit arrangement.</p> |
