| 摘要 |
PURPOSE:To reduce the residual voltage within the range of the load switching current, by inserting the current limiting circuit into the power circuit. CONSTITUTION:The current limiting circuit consisting of transistor 417, Zener diode 413 plus resistances 426 and 427 is inserted into power circuit 4. Thus LED power supply ILED is limited to current IC by which only gate trigger current IGS flows. As a result, nonconducting angle theta of SCR412 decreases, and thus the peak of residual voltage VS shifts to the region having less load current in case the load current decreases. |
