| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a constant current output circuit that can operate even on power supply from a power supply device having a relatively low rated current, and a lighting device having the constant current output circuit. <P>SOLUTION: A constant current output circuit 100 includes: a constant current circuit 120 having a control IC 123 that performs switching control for converting an input current to output a constant current; and an operating power supply circuit 110 for supplying operating power to the control IC 123 when a voltage input into the constant current circuit 120 exceeds a predetermined voltage, and stopping supplying the operating power to the control IC 123 when the voltage input into the constant current circuit 120 is equal to or lower than the predetermined voltage. The constant current circuit 120 stops outputting the current when the control IC 123 stops operating. The constant current output circuit 100 can thus operate even if the rated current of a DC power supply device 200 is relatively low. <P>COPYRIGHT: (C)2012,JPO&INPIT |
