How many degrees of primary school students to learn incandescent
In order to be able to project most of the light to the desktop, the light source installation position of the writing lamp is usually horizontal or downward.
Four types of light source have their own advantages and disadvantages, different people may like the light of different light and brightness, should be due to people and should.
Writing light source lamps generally have four categories: incandescent, halogen, fluorescent and LED.
with ordinary light bulbs 15 watt appropriate, with three primary colors energy-saving lamps 3 watt appropriate.
For young students, but also pay attention to writing, reading distance is best not less than 30 cm; lamp should not be too bright,
