| 摘要 |
PURPOSE:To enable the LED to be in light emission at the time with the turn-on of the power source by a method wherein the power source is connected to a capacitor with a switching element, in a device to put the LED in light emission by charges from the capacitor. CONSTITUTION:A P-N-P transistor (Tr)70 is provided between the power source 10 and the capacitor 30. First, when the power source 10 is turned on, a control signal is outputted from a control circuit 80 at the same time, therefore, Tr70 turns on immediately. This causes the capacitor 30 to instantaneously finish in charging. In other words, since the voltage of the capacitor 30 reaches a required voltage almost at the same time with the power source turn-on, the preparation for the light emission of the LED40 completes at that instant. If a Tr50 turns on at this time, the LED40 emits light at the same time with the turn-on. Therefore, the LED40 emits light in synchronization with pulses fed to the Tr50. |
