| 摘要 |
<p>PROBLEM TO BE SOLVED: To sufficiently prolong the service life of a light emitting element by suppressing the temperature of the light emitting element of an aviation trouble lamp, and also to downsize and make an aviation trouble lamp light- weight. SOLUTION: AC from a commercial power source 40 is full-wave rectified by a rectifying circuit 41. The full-wave rectified AC is switched by an FET 42. The current passing through the FET 42 is smoothed by a smoothing current 43. The smoothed current flows to an FET 4. The current flowing to the LED 4 is detected by a resistor 44. Based on this detection signal, a control signal generating circuit 45 supplies the FET 42 with a control signal, so that the current flowing to the LED 4 is substantially a prescribed current. The calorific value of a driver is reduced due to the switching action of the FET, whereby the temperature of the LED 4 can be suppressed.</p> |
