| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To normally light on the other LEDs except an LED in which malfunction such as disconnection is caused, and the effect of the disconnection is made to the minimum. <P>SOLUTION: A PWM output part 5 PWM drives LED groups 1 to 4 connected in parallel, and energizes peak electric currents around from several times to ten times the size of a rated current. If either one of the LED (1-1 to 1-4) to (4-1 to 4-4) is disconnected, by detecting a voltage of the LED or less has Low level, CPU6 specifies a disconnected LED. The CPU 6 controls an analog SW7, puts a switching element corresponding to the disconnected LED in a conductive state, shunts an electric current and normally lights on the other LEDs except the disconnected LED. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
