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I'm an electronic enthusiast, and very interested in doing experiments and working with whatever I learn in the book.

Recently, I was making a full wave rectifier circuit. In order to find a Zener diode for this purpose, I searched through the net, and it was a utter chaos that I found myself in with the different types of numbering of the diodes and capacitors. My book mentioned that Zeners are numbered usually as 1N.... , that is, Zeners have the prefix 1N. I had to look up the data sheet of each zener available to see which met my needs.

There are similar types of numbering for transistors, ICs and all other electronic components. My question is that, is it possible to identify the characteristics of a particular component by looking at its numbering and not the data sheet? For example, if I say a Zener is 1N5408, as a beginner, I understand nothing but that it is a Zener diode, and then I've to look at the data sheet for other characteristics. Is that the case with everyone? What do you do when you want a particular component with some specifications in particular? Do you just Google it up, or is their some systematic approach to this?

Moreover, can anyone provide me a table by which I shall be able to understand which serial number of components refers to what? For example, BAV99 is a dual diode, whereas BT146 is a triac. How can I understand at the first sight that the given serial number refers to a diode, transistor or such other components? What is their systematic numbering process, if any?

Wrichik Basu
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  • 1N is a prefix used by some diodes , 2N is a prefix used by some BJT's. 1N5408 is a diode NOT a zener diode –  Oct 25 '17 at 18:30
  • @JonRB but the data sheet says "General purpose rectifiers". Doesn't that mean it's a Zener? – Wrichik Basu Oct 25 '17 at 18:32
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    no, it means its a general purpose rectifier. A zener is something very specific, a diode designed to operate in its avalanche region with a more predictable voltage –  Oct 25 '17 at 18:33
  • @JonRB then how can I identify Zeners? I searched google with "zener diodes" and got 1N series as results. So I didn't knew I was wrong. – Wrichik Basu Oct 25 '17 at 18:38
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    Zener's are not typically a part of a full-wave rectifier. I think you have some terminology confused. For part-selection, the big online distributors are your friends as they have parametric selection tools on their web sites. [Digikey](http://www.digikey.com), [Mouser](http://www.mouser.com), etc. – brhans Oct 25 '17 at 18:39
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    The 1N and 2N numbering schemes have no more system than counting the leads. The B… numbering scheme actually **has** a system, starting with the B, which means Silicium. That scheme is called https://en.wikipedia.org/wiki/Pro_Electron – Janka Oct 25 '17 at 18:40
  • your google-fu needs to improve. searching EXACTLY "zener diodes" has wiki as the 1st link, electronic-tutorial as the 2nd. Digikey, RS, Farnell (part providers) then follow, In short each manufacturer uses their own designator for new parts, the generic market then follow suite –  Oct 25 '17 at 18:41
  • @JonRB see [this](https://m.ebay.com/itm/10pcs-1W-5-1V-Zener-diode-1N4733A-1N4733-IN4733A-IN4733-5V1-volt-DO-35-ROHS-/222622184579). Here it says 1N series are Zeners. – Wrichik Basu Oct 25 '17 at 18:41
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    No, it says 1N4733A et al. are zeners. – Janka Oct 25 '17 at 18:42
  • @Janaka so following that, 1N5408 is a Zener as well. Isn't it? – Wrichik Basu Oct 25 '17 at 18:43
  • @WrichikBasu A 1N4728a is a zener yes, not all 1N are zeners. Zeners are a type of diode and 1N usually indicate diodes. BZT prefix are generally diodes –  Oct 25 '17 at 18:44
  • @WrichikBasu NO! the 1N4728a is a standard diode! https://www.diodes.com/assets/Datasheets/ds28007.pdf –  Oct 25 '17 at 18:44
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    No, it isn't. If 1Na is X and 1Nb is X, that doesn't mean **all** 1N are X. – Janka Oct 25 '17 at 18:45
  • @JonRB so how do I identify them specifically? By looking at mouser and such companies? Isn't their any numbering system? – Wrichik Basu Oct 25 '17 at 18:45
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    I have been in the electronics industry for well over 30 years by now and I have never noticed a consistent pattern. Some manufacturers have part numbers you can guess but it is by no means universal. – Warren Hill Oct 25 '17 at 18:45
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    @WrichikBasu you logic is "orange starts with O and is orange so Olives must also be orange in colour because they start with O" –  Oct 25 '17 at 18:46
  • @JonRB the datasheet says it's a rectifier. So can I at least use it for full wave rectification? – Wrichik Basu Oct 25 '17 at 18:47
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    @WrichikBasu by doing exactly that. You go to farnell,RS,Mouser... you enter in what you want "I want a 5.1V zener, axial lead..." and it will shortlist what meets that criteria –  Oct 25 '17 at 18:47
  • @WrichikBasu yes you can... –  Oct 25 '17 at 18:47
  • Moral: electronics not my field. – Wrichik Basu Oct 25 '17 at 18:48
  • Moral: listen to those who's field it is –  Oct 25 '17 at 18:49
  • @JonRB yes, I'm listening. – Wrichik Basu Oct 25 '17 at 18:49
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    @WrichikBasu Zener diodes are a special case of semiconductor diodes, a subset. In general, they are *not* selected for use in a bridge rectifier. There might be a bizarre and unusual reason why someone, someday, could justify their use in bridge rectifier. But I don't think you are the one to be able to make that justification. So you want diodes that are NOT zener diodes. These might include general purpose; fast recovery; Schottky barrier; even perhaps vacuum tube diodes. But in particular it should not be a zener. You picked the one least likely to be applied here. A feat of sorts. – jonk Oct 25 '17 at 19:01
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    part numbering *is* utter chaos. Get used to it. Although there may be small islands of what look like sense, they don't generalise beyond their little islands. Just as you can't assume that all people called Gerald are accountants, you can't assume that all components with an '08' in the part number can take 8 amps. – Neil_UK Oct 25 '17 at 19:08
  • @Neil_UK for a person used to symmetry and proper naming and systematic arrangements of particles using gauge invariances and Lagrangian invariances, or following conservation laws, such utter chaos is difficult to digest. :-( – Wrichik Basu Oct 25 '17 at 19:11
  • That's a very good parallel, one I use very frequently in fact. I can understand physics, it's based in all sorts of symmetries and conservation laws and other good stuff. I can't understand my TV video recorder, because it was written by humans, why doesn't it record afternoon programmes when it's off, why doesn't it record sound on BBC2 SD, when it does for other channels. You know what? Component numbering schemes are the work of humans. This group follows one convention for a bit, those groups use a different convention, and he just picks numbers sequentially. Chaos, Babel, get used to it. – Neil_UK Oct 25 '17 at 19:24
  • @Neil_UK he he :-D – Wrichik Basu Oct 25 '17 at 19:30
  • It can be easy to confuse a Schottky diode symbol for a Zener diode symbol. Maybe the diodes in the bridge rectifier are supposed to be Schottkies rather than Zeners? – Oskar Skog Oct 25 '17 at 20:58
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    This is where the parametrics on the websites of vendors like Farnell and RS are very handy. And it sounds cheesy, but it's often useful to look at what they've got high stock levels of, because it means other people are using a lot of that part. – Ian Bland Oct 25 '17 at 21:25
  • @Janka 1N and 2N refer to the number of semiconductor junctions, not the number of leads. a diode has one junction (between the P and N type regions), so it's 1N. Transistors have two junctions (e.g. P-N-P or N-P-N), so are 2N – Reversed Engineer Oct 26 '17 at 08:18
  • So thyristors have 3N? – Janka Oct 26 '17 at 08:23

2 Answers2

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To give you some hope, the 1N and 2N series refer to the number of junctions in the devices.

schematic

simulate this circuit – Schematic created using CircuitLab

  • 1N will almost (just covering the exceptions) always mean a diode of some sort as they have only one PN junction.
  • 2N refers usually to bipolar junction transistors which have two PN junctions.
  • Here is a 3N187 - a dual insulated-gate field-effect transistor. It has four leads.

A web search found some 4N and 6N but they seem to be opto-couplers and I can't see the continuation of the 1N, 2N pattern.

See stephenvh's answer to Is there any reasoning behind component names? for further information.

Transistor
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Part numbers make sense... in the sense that they are not completely random. But they aren't supposed to make sense to regular people who don't work with electronics on a daily basis. In most cases, parts are just called what the original manufacturer decided to call them, so predictably it's a mess.

If you know a bit of trivia regarding the part's history, sometimes you can tell. One example is the 7400 series - when you see the 74somethingssomething, you should immediately proclaim that some old-school boolean stuff must be going on (that tends to impress the newbies: "he must know about every single part number since the sixties!").

Sometimes the part number encoder some parameter (eg LM7805 are +5V regulators, LM7812 are +12V regulators, and LM7905 are -5V regulators), but it doesn't happen nearly as often as it should.

What I do when I want to look for a part with certain characteristics ("at least 1A, reverse breakdown voltage of 60V") is to use the parametric catalog of some online store.

FrancoVS
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