| 摘要 |
PURPOSE:To start a lamp easily, though it is small, by performing the start of the lamp with simple control. CONSTITUTION:A series circuit of a lamp and a switching element SW is connected in parallel with a power source E, and the switching element is controlled with a signal Vd. First, when the signal Vd gets on a high level, the switching element SW is turned on, and a control circuit 2 applies voltage VL to a lamp 1. But, since the frequency of the pulses is low, it is under the startable voltage, so the lamp 1 does not start, and a lamp current IL does not flow. By raising the pulse frequency and lowering the startable voltage and making it fall below the crest value of the voltage VL, the lamp 1 becomes possible of starting, and the lamp current IL flows. |
