European Code Or Japanese Code Or…………..
Those days when i started my electronics course, i was exposed to only few standard codes for transistors. It is either the European or the Japanese code. That means when you see a transistor part number it can be either C3039 or 2SC3039. Both the part numbers are the same and can be used in the equipment. The main difference is only in the code. The European code starts with C (for NPN transistor) and the Japanese code starts with 2SC. It was quite easy to identify whether the transistor belongs to NPN, PNP, Fet, Triac, SCR and etc. We as repair tech have no problem in identifying them.
Since there are so many semiconductor manufacturers in the world nowadays, lots of them never follow the standard transistor coding anymore. They came out with many funny numbers (codes) and even finding the internet could hardly locate what type of transistor it was. Because of this, it gave lots of headache to electronics repairers around the world. Just imagine you found a shorted device (all legs have reading when check with meter) that have the look of a transistor (3 pins) with the part number of ZBD689A1 and you do not have the schematic or even data sheet. In what way you will know this 3 leg device whether it is a bipolar transistor, FET, SCR, Triac and etc ? A wrong guess will consume your repair time and sometimes it may burn other components too in the equipment.
Lets take another example, if you repair CRT Monitor you will definitely came across HORIZONTAL OUTPUT TRANSISTOR (HOT). Fairchild semiconductor came out HOT with the part number that start with “J” like the J6810 and etc. If you are new in this repair field, you may have thought that it was a P-channel Mosfet because according to standard code a P-channel Mosfet part number will start with J or 2SJ!
If all the manufacturers could follow the standard transistor coding, then we will have less problem in identifying them.