ANTIQUE-RADIO-LAB

Antique Radio Forum for Collectors antique-radio-lab.forumotion.com
 
HomeHome  RegisterRegister  FAQFAQ  SearchSearch  Log inLog in  

Share | 
 

 Zener diodes

View previous topic View next topic Go down 
AuthorMessage
copain



Join date : 2011-12-28

PostSubject: Zener diodes   2012-11-28, 6:00 am

A project I'm interested in calls for 8.2 v./2 w. Zener diodes. Two questions: (1) Does such a rated Zener diode exist? (2) If so, who sells it? I can't find this rating at any of the usual parts sources.
Back to top Go down
Cliff Jones
Site Administrator
Site Administrator
avatar

Join date : 2010-11-22

PostSubject: Re: Zener diodes   2012-11-28, 7:55 am

They are out there but finding 2 watt is a bit harder. I'll look some more,found one! dang not in stock!

Click here for Digikey

_________________
I'm a Science Thinker, Radio Tinkerer, and all around good guy. Just ask Me!
Back to top Go down
copain



Join date : 2011-12-28

PostSubject: Re: Zener diodes   2012-11-28, 2:08 pm

I bookmarked the Digikey page and will watch it for restock info.
Back to top Go down
FrankB
Moderator
Moderator
avatar

Join date : 2010-11-22

PostSubject: Re: Zener diodes   2013-03-09, 6:24 pm

Should be available from NTE.
Back to top Go down
stareagle

avatar

Join date : 2012-12-17

PostSubject: Re: Zener diodes   2013-03-17, 6:54 pm

I have lots of NOS diodes etc. From the 60's on I guess. How do you ID these small glass ones? confused
Back to top Go down
FrankB
Moderator
Moderator
avatar

Join date : 2010-11-22

PostSubject: Re: Zener diodes   2013-03-17, 10:21 pm

On the unmarked diodes you have to sort of guess.

A good ohmmeter can tell you if its silicon or germanium.

If you think its a zener you can use the following procedure to check its break down voltage rating.
(I have posted this before on several forums.)

Use an eye type capacitor bridge with VARIABLE output testing voltage.

Hook the suspected Zener across the 2 test terminals with correct polarity, of courrse; and put the tester on a test position for looking at the breakdown voltage of a capacitor.

Hook a voltmeter meter across the 2 test terminals.

Crank up the test voltage and see when the voltage fails to go farther up on the meter; i.e. If the meter indicates 150V and you have the test voltage cranked up to 250, the diode is a 150V Zener.

There is a built in current limiting resistor in the old eye tube testers, and the diode wont be harmed IF its really a Zener.

If its not, well, I have never tried the test with a normal diode.

Now most of the old eye type testers go to 600V, so it IS possible to have a zener with a breakdown voltage in excess of the 600V. A very rare, but possible circumstance.

I have used this method for years with 100% success so far.

This test is fantastic for the "shock pack" type assortments of unmarked and mis- marked zener diodes as well as those salvaged from TV's and such.
You can also easily tell if the zener is leaky too.
Back to top Go down
copain



Join date : 2011-12-28

PostSubject: Re: Zener diodes   2013-11-05, 1:26 pm

Still don't see the 8.2 v./2 w. Zener diodes I was looking for in above post in Digikey's site, so will no longer look there.
Back to top Go down
copain



Join date : 2011-12-28

PostSubject: Re: Zener diodes   2014-01-03, 2:58 pm

Double checked; still no 8.2 v./2 w. Zener diodes. I now believe that no such animal exists and that the original project calling for this nonentity was made up.
Back to top Go down
FrankB
Moderator
Moderator
avatar

Join date : 2010-11-22

PostSubject: Re: Zener diodes   2014-03-10, 5:51 pm

NTE5122A 8.2v 5w

This will work for you.
Back to top Go down
Cliff Jones
Site Administrator
Site Administrator
avatar

Join date : 2010-11-22

PostSubject: Re: Zener diodes   2014-05-06, 3:10 pm

Also you can stack 2 (two) 4.1v zeners to get 8.2 volts ( if my college lab work was worth it )

_________________
I'm a Science Thinker, Radio Tinkerer, and all around good guy. Just ask Me!
Back to top Go down
 
Zener diodes
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» The dreaded 'buzzing' problem

Permissions in this forum:You cannot reply to topics in this forum
ANTIQUE-RADIO-LAB :: Radio Repair Bench :: Radio parts, Tools, and supplies. :: Solid State Devices (Transistors, I.C.s ect.) :: S.S. Diodes-
Jump to: