finding data sheets for discontinued parts with no prefixes?

[Leftrights]

I get as many of my parts as I can for torn apart stereos and such so is there anyway to find a data sheet with only the case markings.

Some I don't have problems with... just add a 2N or BC and search.  But there are some (that are probably discontinued) that I can't find anywhere.

So what do I do when all I gots to work with is C1684 printed on the case? :wink:

[Ansil]

if it is a transistor hook it up to the multimeter and let her rip.

ps if it is a transitor i had one with the same markigns and it was standard pinout.

[Mark Hammer]

The C *is* a prefix, just a shortened one.  Japanese transistors have a "2S" before the rest of the number.  So, C1684 is probably a 2SC1684, the same way a C1815 is a 2SC1815.  I have a huge (and I mean huge - 70M - way too big to post or mail around) pdf of a Japanese transitor manual which lists specs for a large assortment of trannies way back to the 2-digit germanium ones (e.g., 2SA12).  I can provide some specs for those devices that datasheets are largely impossible to find on-line, if you want.

Here is what I have for a 2SC1684:
Silicon, for RF and AF purposes
Vcbo - 30v
Vceo - 25v
Ic - 100ma
Power dissipation - 400mw
Icbo -  1ua
Vcb - 10v
hfe - 250
Vce - 10v
Vcb - 10v
Capacitance - 3.5pf

There are a few other parameters listed but the description is in Japanese so, uh, I'll overlook that.

Hope this helps.

Mark

[Johan]

the text below comes from the factsheets at www.elfa.se  those factsheets contain almost everything you need to know when designing anything...their old slogan was "everything from antenna to ground"  



The European Pro Electron System
Two or three letters followed by a 3- or 4-digit group of numbers
provide a rough understanding of the component type as well as
the power class.
The first letter indicates the material:
A Ge, Germanium or a material with a band gap of 0.6-1 eV
B Si, Silicon or another material with a band gap of 1-1.3 eV
C GaAs, Gallium arsenide or another material with a band
gap greater than 1.3 eV
The second letter indicates component type:
A Diodes, signal, low-level
B Capacitance diodes
C Transistors, low frequency, low level
D Transistors, low frequency, power
E Tunnel diodes
F Transistors, HF, low level
H Diodes, Hall effect components
L Transistors, HF, power
N Opto switches
P e.g. Photo-transistors
Q e.g. LEDs, laser diodes
R Thyristors, low level
STransistors, switch, low power
T Thyristors, power
U Transistors, power, switch
W Surface wave components
X Diodes, HF multiplicator
Y Rectifiers, booster
Z Zener diodes, voltage reference


The Japanese JIS System (Japanese Industrial Standard)
First digit (one less than the
no. of connections):
1 Two connections
2 Three connections
3 Four connections
The two following letters:
SA PNP transistors and Darlington (HF)
SB PNP transistors and Darlington (LF)
SC NPN transistors and Darlington (HF)
SD NPN transistors and Darlington (LF)
SE Diodes
SF Thyristors
SG Gunn diodes
SH Unijunction transistors
SJ P-channel FET
SK N-channel FET
SM Triacs, bidirectional thyristors
SQ LEDs
SR Rectifier diodes
SS Signal diodes
ST Avalanche diodes
SV Capacitance diodes, PIN diodes
SZ Zener diodes
The serial number consists of two to four digits within a number
range between 10 - 9999. This is followed by a suffix that consists of
one or several letters. The last letter indicates the area in which the
semiconductor is used.
D Approved by the Japanese telecom authorities (NTT)
G The component is used for communication
M Approved by the Japanese Navy (DAMGS)
N Approved by the Japanese Broadcasting Corporation
(NHK)
SDesigned for industrial applications
The Japanese Industrial Standard (JIS) designation does not
indicate whether a semiconductor is manufactured from silicon or
germanium. The first two characters are frequently omitted on
drawings as well as on the printed serial number on the components
themselves. This means that a 2SC940 type transistor may
very well be marked C940.

Johan