| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable dimmer control of a light emitting body with the simple structure by obtaining AND of the output of a comparator and the output of a one-shot multi-vibrator, and turning the control voltage to be output from a driving circuit on/off so as to control the current flowing the light emitting body connected to a first semiconductor element. SOLUTION: When a switch 6b is turned off, a comparator 5 repeatedly outputs 1 and 0. When a counter 9 counts the predetermined number and outputs the pulse, output of a one-shot multi-vibrator 10 is changed from 1 to 0 so as to output the pulse. Output of an AND circuit 8 becomes 0, and the control voltage output from the driving circuit 3 becomes 0, and current does not flow to FET1, FET2, and a lamp 7 is dimmed. Luminance of the dimmer can be adjusted more by changing the pulse width output from the one-shoe multi-vibrator 10. When the switch 6b is turned on, the comparator 5 always outputs 1, and current is always flowed to FET1, FET2, and the lamp 7 emits the light without being dimmed.</p> |
