| 摘要 |
<p>PURPOSE:To provide an illumination power supply capable of supplying power which can well suit the light sources having different wattages, by sensing whether a cooling means is equipped, and controlling the power to the applicable illumination device. CONSTITUTION:When power is supplied to an illumination device equipped with no fan, a transistor Q3 is turned off and no current flows in a resistor R3, and a switching transistor Q1 to turn on an off the fan operating current is turned off. When power is supplied, on the other hand, to an illumination device equipped with a fan FA1, the current in reverse direction is blocked by a diode D1 and a current 12 flows, and the fan FA1 is rotated. A trigger frequency control part TC restricts the frequency of trigger pulses tp to be supplied to the gate of a thyristor S1 to low frequencies, when a switching transistor Q4 for changing the trigger frequency according to existence/non- existence of fan FA1 is off, and restricts to high frequencies when Q4 is on, and thereby the flashing time of a xenon lamp LA1 is controlled.</p> |
