| 摘要 |
PURPOSE:To make it possible to attain an increase in the quantity of light of a brake lamp without the lift of the brake lamp being remarkably reduced and with no special boost circuit being provided, by constituting the brake lamp with light emitting diodes, and by providing an adjusting mechanism for increasing light emitting current when the vehicle speed exceeds a predetermined value. CONSTITUTION:When the vehicle speed is below a predetermined value, the output of a vehicle speed sensor 17 is at a low lever L so that a transistor 15 is deenergized, and even if the vehicle is braked so that a power feed path from a battery 1 to a brake lamp 13 is established, the transistor 15 is still deenergized although the brake lamp 13 is turned on, thereby a relay 7 is left to be opened. When the vehicle speed exceeds the predetermined value, the output of the vehicle speed sensor 17 is at a high level H so that the transistor 15 is energized to close a contact 7-2. The current value of the power feed path from the battery 1 to the brake lamp 13 is determined in accordance with a resistance value obtained by resistors 9, 11 which are connected together in parallel, and therefore, when the vehicle speed exceeds the predetermined value, the resistance value of the parallel connection of the resistors 9, 11 becomes greater than the resistance of the resistor 9 alone so that current value becomes large,thereby it is possible to turn on the brake lamp 13 with a relatively large light quantity. |
