| 摘要 |
PURPOSE:To make a light source color to a cool color temperature when it is hot and a warm color temperature when it is cold and produce a comfortable atmosphere by providing a control means for setting the color temperature high when the circumferential temperature is increased and low when the circumferential temperature is lowered. CONSTITUTION:A control means is formed of a thermistor TH, a capacitor C3, an astable multivibrator 5, and a monostable multivibrator 6. When the circumferential temperature is high, the thermistor TH is highly resistant, so that a waveform having a large duty ratio is inputted to the base of a transistor Q1 connected in series to a lamp 1. When the circumferential temperature is low, conversely, a waveform having a small duty ratio is inputted to the base of the transistor Q1. Thus, the color temperature is changed depending on the circumferential temperature, in which the color temperature is high at a high circumferential temperature and low at a low circumferential temperature. Hence, the light source color is made to a cool color temperature when it is hot, and a warm color temperature when it is cool, and a comfortable atmosphere can be produced. |
