| 摘要 |
PROBLEM TO BE SOLVED: To provide a constant current circuit flowing current with a good response to a change of input signals. SOLUTION: The constant current circuit comprises: a light source 1; a switching means 3 connected to the light source 1 for changeover between lighting on/lighting off of the light source 1; a resistor 4 for current detection connected to the switching means 3; a current value adjustment means 2 inputting a first voltage value A pulse-outputted from a control means, and a second voltage value in the resistor 4, adjusting the second voltage value by activating the switching means 3 so that the first and the second voltage values are to be nearly the same, and making a current flowing in the light source 1 nearly constant, and a rectifying element 5 connected to an output side of the current value adjustment means 2 and the resistor 4. COPYRIGHT: (C)2009,JPO&INPIT |
