What are the types of lampholders, how are they distinguished? E14 E27 MR16
And the characteristics of the standard with the provisions of the standard lamp can be used with the current lamp has been used symbols.If this lamp in the electrical or mechanical requirements can not (or not completely) interchangeable, then the capital letters X, Y, Z or U, or a combination of two or more letters added to the base symbol.
W --- indicates the lamp end, the electrical contact between the lamp and the lampholder is done directly through the lead on the surface of the lamp end, and the glass part (or other insulating material part) of the lamp end is not necessary for the installation of the lamp in the lamp holder For a single lamp that can replace the entire lamp end and symbolize the same interchangeability requirements of the material, it can also be symbolized;
The (a) part of the symbol consists of one or more uppercase letters, indicating the type of the lamp cap. The following letters represent the lamp cap, but they also have similar meanings for the lampholder.
The symbol in front of the slash in the sign symbol indicates the content that is important for the interchangeability of the lamp holder in response to the lamp holder. The particular part of the symbol is the same for the lamp holder and the lamp holder used (If present) represents some important dimensions of the lamp cap, but these dimensions are not a necessary part of the interchange requirements of the lamp in the lampholder. However, It is important to have a common interchangeability of the different sources of lamps on the same type of lamp.
One of the purposes of this symbolic system is to make each designated symbol short, legible and helpful in indicating its use, which consists of letters, numbers and symbols, each of which has its own meaning For each particular lamp cap and lampholder it should only be named with a symbol that can not be used to identify the material used in the lamp holder.