I have a transistor marked D401-Y, made by SEC.
I see data sheets marked CSD401, 2SDS401, KSD401, MPD401.
I think it's clear that the device is essentially an NPN Power Transistor.
But why the diffrent prefixes CS, 2S, KS? Are these particular manufacturers markings?
I think the Y is some kind of suffix. Thanks.
"Richard"
** The " 2S " prefix comes from the original EIAJ ( Electronics Industry Association of Japan ) standards for numbering transistors. This organisation is no longer operating and has been replaced by JETIA." KS " prefixed part numbers often mimic the EIAJ ones, but are made in Korea and not entitled to use the EIAJ numbers.
At a guess, " CS " prefixed devices are made in China.
Often, the above prefixes are not printed on the packages of the device, purely to save space AFAIK.
** The Y suffix indicates the device's Hfe ( ie beta) falls in the range 120 to 240.This info is on the data sheet for the 2SD401.
..... Phil
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