the problem with datasheet websites

Discussion in 'Electronics Resources' started by bobbyrae, Sep 12, 2009.

  1. bobbyrae

    Thread Starter Active Member

    May 14, 2009
    Admittedly, I am new to this stuff, but I find one really frustrating problem with the datasheet websites. Maybe someone here has an answer.

    The problem is that many components do NOT have the full component number on them! So if I look at the component, write down the number, and then go to the datasheet archive, it says "no results". On the other hand, if you can find the schematic, where they give the complete number, then the datasheet archive can find it. So why don't the archive people realize this and provide a better search capability?

    Here's an example:

    An old audio receiver from the '70's has a bunch of transistors labelled "C1918". This will give the old "no results", but when I found the schematic which indicates the full designation of "2SC1918", then the archive can help.

    But WHY not give search results for anything that matches "C1918" to start with?
  2. hgmjr


    Jan 28, 2005
    214 provides for the use of wildcard search. For example, you can look for *74HC00* and get a list of all different versions of the part.

  3. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    Other sites, like, allow you to specify "begins with" or "contains" in your search term.

  4. bobbyrae

    Thread Starter Active Member

    May 14, 2009
    You ARE right about that, but the downside is that site seems to have less coverage. When I went to find items that contain "C1918" it does NOT come back with 2SC1918, and even when I type the whole number it still can't find it.

    So with this particular transistor, one still could NOT find the datasheet by just looking at the component!
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    There are several hits on "2sc1918". Data sheets are not very forthcoming, though. It's obsolete.

    One handy work-around is the site - - that gives two subs. The specs for them give a pretty good idea about the actual ones for the 2SC1918.
  6. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    The shortcuts on component markings are common.

    The omitted 2S is one of the friendlier ones, wait until you try to identify surface mount transistors - these typically have markings completely unrelated to the actual part number.
  7. soda

    Active Member

    Dec 7, 2008

    Know I'm a little late on this but company's mark their components with a "c" when they don't want people to identify it. You can overcome this by getting yourself a "ECG SEMICONDUCTORS MASTER REPLACEMENT GUIDE" from Phillips. I bought mine back in 1982 but maybe it's still available.

  8. beenthere

    Retired Moderator

    Apr 20, 2004
    Can you give a source for your statement? -
    We had established that the transistor marked C1918 was actually a 2SC1918. Omitting the "2S" is quite common.
  9. DatasheetArchive

    New Member

    Oct 15, 2009
    We've added millions of new datasheets to the Datasheet Archive website this week. This will hopefully help.

    We are also looking for manufacturer data books on DVD or CD. If anyone has some they would like to donate please contact

    Many thanks.
  10. studiot

    AAC Fanatic!

    Nov 9, 2007
    I agree that finding datasheets has become increasingly difficult.

    Quite a few former free sites are no longer free and various entrepreneurs are using forced marketing techniques to push their paid for databases to the top of Google.

    Slightly better, some sites have now become membership sites.

    Manufacturers too have started reusing type numbers for other purposes.
    In fact this has always happened, it's just more common.

    So a BC221 was both a transistor and a forces radio set.

    Bobby you'd better get used to the Asians dropping the 2S from parts id's as you can find it on 2SB, 2SC, 2SD etc.

    Sometimes, but not always 2S# = 2N and sometimes PN# = 2N.

    Look on Ebay for transistor data books (eg Towers) they come up occasionally.

    Another thing to watch out for is that components have been 'improved' over the years. So a modern datasheet will give a false impression of the capabilities of an old component. eg a 2N3702.
    Even in the old days you needed to check which manufacturer made the componeent as there were differences.

    Or manufacturers have produced various pinout versions without any indication eg the 2N3819 has appeared in a variety of pinouts, with disasterous results if you get it wrong.

    Talking of pinouts here are a cpiple of useful sites.
    Last edited: Oct 15, 2009