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Using Arduino => General Electronics => Topic started by: mrbug on Jan 31, 2011, 05:19 pm

Title: 3.6V .5W zener diode appearance
Post by: mrbug on Jan 31, 2011, 05:19 pm
What does a 3.6V .5W zener diode look like? I'm attempting to build something with some salvaged (free) parts, but I'm not sure what to look for before desoldering.
Title: Re: 3.6V .5W zener diode appearance
Post by: RuggedCircuits on Jan 31, 2011, 05:32 pm
Probably like this (though there are lots of other possibilities):

(http://media.digikey.com/photos/Microsemi%20Photos/2EZ3.6D5_sml.jpg)

--
The Quick Shield (http://ruggedcircuits.com/html/quick_shield.html): breakout all 28 pins to quick-connect terminals
Title: Re: 3.6V .5W zener diode appearance
Post by: westfw on Jan 31, 2011, 05:44 pm
Here's a picture from digikey:
(http://media.digikey.com/photos/Micro%20Commercial%20Photos/1N5227B-TP_sml.jpg)
Note that 0.5W zeners from a particular manufacturer are going to look alike regardless of voltage, except for the part number that may or may not be legible...
Title: Re: 3.6V .5W zener diode appearance
Post by: mrbug on Jan 31, 2011, 06:41 pm
Darn, looks like I am going to just have to keep desoldering until I find something with markings that match one on digikey.

I have quite a few of both types so far, but none of them have the correct specifications.
Title: Re: 3.6V .5W zener diode appearance
Post by: Grumpy_Mike on Jan 31, 2011, 08:29 pm
You are best getting the numbers off the parts you remove and typing them into google followed by the words data sheet. That should tell you what they are. Remember that any wattage rating above 0.5w will do just as well.
Title: Re: 3.6V .5W zener diode appearance
Post by: swetrack on Jan 31, 2011, 09:29 pm

You are best getting the numbers off the parts you remove and typing them into google followed by the words data sheet. That should tell you what they are. Remember that any wattage rating above 0.5w will do just as well.

+1
It is almost impossible to tell the difference between a diode and a zener diode without the label.
How ever, with some good will you could make a test jig with, lets say 20Vdc and a 20kOhm R. If you connect your "zener diode?" forward you will have typically 0,6 to 0,7V over diode and if connected backward you will see the zenervoltage. It will of course not work if Zener voltage is over 20Vdc, and if it is a regular diod it will stop backward and you will measure 20V.

Edit: You may be better of with a 4,7kOhm R and you should be aware of that forward voltage can be higher maybe 2V or so. This is not bulletproof but it should work for most zener diodes out there.

Thank you