Function introduction: The colorful Christmas tree kit consists of two light boards and one light board base, which form a tree-like shape. The colorful LEDs on the edge of the two light boards alternately flash like water, automatically changing seven colors, at night. It looks radiant and illuminates the surrounding environment. It has a beautiful effect and can create a pleasant atmosphere. This kit is very capable of exercising the welding ability, suitable for practical training hands and enlightenment exercises for electronic production. It is a very good choice whether it is used for self-appreciation or as a gift. Circuit principle: 18 LEDs are divided into 3 groups. When the power is turned on, 3 triodes will contend for conduction. However, due to the difference in components, only one transistor is turned on first. It is assumed that Q1 is turned on first, then D1 -D6 is lit. Because Q1 is turned on, its collector voltage drops so that the left end of capacitor C1 f