Abstract: A heat exchanger includes a fin set formed by a plurality of fins stacked together and a refrigerant pipe set passing through the fin set. The fin set includes a connection member, and a first fin member and a second fin member connected to each other via the connection member. An included angle between the first fin member and the second fin member is larger than zero. The first fin member and the second fin member are arranged at two sides, respectively, of a notch of the fin set. The notch is located at an air input side and/or an air output side of the connection member.

Abstract: A lamp unit, including: a main stem including a first end and a second end, and at least two branches. The at least two branches extend outwards from the first end of the main stem. The second end of the main stem includes a connection part. One end of each branch includes a mounting part which is adapted to accommodate a light source or corresponds to a connection part of another lamp unit. In use, the connection part is electrically connected to the power supply, and each mounting part is provided with a light source or is connected to the connection part of another lamp unit. The invention also provides a lamp including a plurality of the lamp units.

Abstract: A lamp unit, including: a main stem including a first end and a second end, and at least two branches. The at least two branches extend outwards from the first end of the main stem. The second end of the main stem includes a connection part. One end of each branch includes a mounting part which is adapted to accommodate a light source or corresponds to a connection part of another lamp unit. In use, the connection part is electrically connected to the power supply, and each mounting part is provided with a light source or is connected to the connection part of another lamp unit. The invention also provides a lamp including a plurality of the lamp units.