| 摘要 |
PROBLEM TO BE SOLVED: To provide an LED illumination device capable of carrying out sure operation. SOLUTION: A detecting voltage correction diode 15 is newly added, an inexpensive correction circuit is constituted by utilizing a constant voltage effect of a forward voltage of the detected voltage correction diode 15, and a detection voltage of a resistor 11 for detection is raised, and inputted into an inverting input 21 of a differential amplifier circuit 2. A resistor 16 for current supply is added in order to make a current flow in the detected voltage correction diode 15. By this constitution, the correction of a voltage drop amount between a base and an emitter or between a gate and a source of a constant current driving element 10 can be made if a variable resistor 33 is made to have higher resistivity, an output voltage does not appear in an output 22, and a current break becomes possible between a collector and the emitter or between a drain and the source of the constant current driving element 10. COPYRIGHT: (C)2009,JPO&INPIT |
