| 摘要 |
<P>PROBLEM TO BE SOLVED: To protect a lighting device from abnormal temperature rise due to an abnormal load, while preventing the malfunction of protection operation. <P>SOLUTION: An LED lighting device to perform lighting control of an LED 19 comprises: a drive circuit 14 which controls on/off of a switching element 15; voltage detection circuits 21 and 22 which detect an output-end voltage; first comparison means 23 which compares an output voltage value obtained from the voltage detection circuits with a first reference voltage; second comparison means 24 which compares the output voltage value obtained from the voltage detection circuits with a second reference voltage lower than the first reference voltage; and control means 20 which controls the drive circuit so that it performs protection operation when one of the first and second comparison means notifies that the output voltage value exceeds the first or second reference voltage. If the output voltage value continues to exceed the second reference voltage for a predetermined period of time, the second comparison means 24 notifies the control means 20 of the excess. <P>COPYRIGHT: (C)2013,JPO&INPIT |
