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zanov
Joined: 09 Jun 2004
Posts: 61
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 28 Jul 2004 20:46 0.6v zener diode forward bias 1n4001 |
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How do you distinguish a regular diode, a zener diode or for the matter of fact a schottky diode just using the resistance? I know there is a trick for this I sawear I read it somewhere.
They are have inscription 1N4 on top and number 723, 733 on them. I have at least 50 of those and all are zener and regular diodes for sure.
thanks
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mamali
Joined: 29 Apr 2004
Posts: 387
Helped: 4
Location: between hell and heaven
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28 Jul 2004 21:26 zener 4001 diode 50v datasheet |
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| zanov wrote: |
How do you distinguish a regular diode, a zener diode or for the matter of fact a schottky diode just using the resistance? I know there is a trick for this I sawear I read it somewhere.
They are have inscription 1N4 on top and number 723, 733 on them. I have at least 50 of those and all are zener and regular diodes for sure.
thanks |
just reverse bias it, zeners then have, say, a fix 6V voltage, diodes dont. thats it
marti
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flatulent
Joined: 19 Jul 2002
Posts: 4877
Helped: 324
Location: Middle Earth
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28 Jul 2004 21:29 what is a regular diode |
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| More details. When you do the reverse and forward bias test use a current limiting resistor. Schottkys will have 0.3 V forward and silicon is more like 0.6 V.
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Big Boy
Joined: 20 Jan 2004
Posts: 253
Helped: 10
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29 Jul 2004 1:07 diode or zener diode distinguishing |
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Do a search on the net for the part numbers... Or enter them in digikey web site.
Some zener have much higher reverse voltage, so they could be mistaken if testing reverse voltage without knowing their rating.
Ex: 1N4733 (is a zener, 5.1V).
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zanov
Joined: 09 Jun 2004
Posts: 61
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29 Jul 2004 1:26 regular diode |
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| Big Boy wrote: |
Do a search on the net for the part numbers... Or enter them in digikey web site.
Some zener have much higher reverse voltage, so they could be mistaken if testing reverse voltage without knowing their rating.
Ex: 1N4733 (is a zener, 5.1V). |
That is the problem: They all say 1N4, etc. I have one says 1N the after 4001, resistance is 4.5Mohm if forward, then infinit reversebly measured.
I can not measure it in live circuit resistance because it will blow the fuse of multitester.
mamali's and flatulent are very useful.
I am going to test the rectification first, for the zeners I can measure them just as we do in unregulated power supply.
Something else more came to me with this Pandora box of un-named 150 diodes: 20 of them are Shockey's. I need a Curve Tracer. So important now.
thank you guys.
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white_shadow
Joined: 21 May 2004
Posts: 41
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30 Jul 2004 10:49 zener diode trick |
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You can't distinguish them from resistance alone. Resistance is a linear value and diodes are one of the very first non-linear devices mentioned.
Impedance is another story, I have no ideal about that.
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barrybear
Joined: 22 Nov 2001
Posts: 268
Helped: 6
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30 Jul 2004 12:33 Re: How do you distinguish a regular diode, a zener diode? |
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I do not believe that it is possible to tell by resistance alone. By far the best way is to read the identification on the component and refer to a eqivelents referance. All other tests are a little hit and miss.
Barrybear
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Big Boy
Joined: 20 Jan 2004
Posts: 253
Helped: 10
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30 Jul 2004 12:42 Re: How do you distinguish a regular diode, a zener diode? |
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Just take the two parts.
For example, you have 1N and 4001. There's not enough room on a diode to print the whole part number on one line si the manufacturer split them across multiple lines.
So, the above really is 1N4001. Most diodes do start with 1N. Like many transistors start with 2N.
You can not test with resistance.
If you have a component replacement book (like the ECG or the NTE), it become much easier too.
For example, if you go to digikey web site, you punc-in 1N4001, you get many results (depending on which package the diode is made), but all come to:
RECTIFIER 1AMP 50V
This meen a regular diode, 1Amp, with reverse-voltage 50V. Note that reverse voltage rating does not meen that this is a zener, and must not be used as such.
You can click on the link on the left of the description, and on technical/catalog information link, and there, you can get datasheet too 
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zanov
Joined: 09 Jun 2004
Posts: 61
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31 Jul 2004 2:11 How do you distinguish a regular diode, a zener diode? |
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| How much an IV curve tracer costs? Looks like that is the only option and I see how important is to have this kind of equipment.
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Sinisa
Joined: 03 Mar 2003
Posts: 337
Helped: 66
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31 Jul 2004 2:40 Re: How do you distinguish a regular diode, a zener diode? |
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| It's not that difficult to build one. You just need scope with x-y inputs.
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eltonjohn
Joined: 22 Feb 2002
Posts: 1751
Helped: 28
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31 Jul 2004 3:07 Re: How do you distinguish a regular diode, a zener diode? |
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zener diodes are very simple ..This is a high school topic ..
is just a simple courbe that expalins the behavior os it
Is a diode that conducts in both ways .. The zenner Voltage is the voltage necessary to conduct reverse biased . it can be very low as 1.5V or very high as 30v or more but is necessary to protect the rush of current once the zenner voltage is achieved .so a zener diode is always protected by a resistor .Otherwise you will damage it .
The use is a voltage regulator .. The zenner voltage provides the reference for an amount of current . If more curent is needed then you use the combination zener + resistor and a power transistor . This is the basic power regulated POWER SUPPLY ..!
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Google
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31 Jul 2004 3:07 Ads |
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bbarney
Joined: 31 Jan 2004
Posts: 209
Helped: 15
Location: canada
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31 Jul 2004 3:42 Re: How do you distinguish a regular diode, a zener diode? |
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heres a couple lists of zener 's and most other diodes,it may help you sort out your mess.
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bbarney
Joined: 31 Jan 2004
Posts: 209
Helped: 15
Location: canada
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03 Aug 2004 0:28 Re: How do you distinguish a regular diode, a zener diode? |
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this is an article on building a zener diode tester
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saubhik
Joined: 27 Apr 2007
Posts: 141
Helped: 8
Location: India
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21 Jun 2007 12:29 Re: How do you distinguish a regular diode, a zener diode? |
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just check out the reverse bias condition which directly tell u that which one is zener and which one is not .....
goood luck ....
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Shans60
Joined: 07 Jun 2007
Posts: 26
Helped: 3
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21 Jun 2007 14:14 Re: How do you distinguish a regular diode, a zener diode? |
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| Usually in the reverse bias the ordinary diode experiences sudden break down but the zenar diode have a constant voltage of approx 6.9 volts so u can easily identify bet them
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