| 摘要 |
PURPOSE:To enable partial troubles of signal lamps mounted on vehicles to be detected without providing any special transistor control circuit by detecting current of the signal lamps and causing the detected current to be a factor for converting a transistor amplifier controlling the signal lamps to a transmitter. CONSTITUTION:When a vehicle is turned right for example and a direction indicating switch 2 is connected to signal lamps 3-5 of the right side winkers, current is supplied to a NPN type output transistor 16 and a resistance 15 of a transistor amplifier, and voltage produced in the resistance 15 to detect current of the signal lamps 3-5 is positively fed back to a transistor 10 through a capacitor 14 and a resistance 13, and the transistors 10, 16 become conductive so that the signal lamps 3-5 are turned on. When, the charge of the capacitor 14 is changed over to the discharge, the transistors 10, 16 are turned off to turn off the lamps 3-5. Then, the charge amount of the capacitor 14 varies with the current of the signal lamps 3-5 to determine the length of flashing cycle so that the flashing cycle is shortened to detect troubles if any one of the signal lamps 3-5 is disconnected. |
