The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: Tumbleweed on 17.07. 2014 19:59

Title: zener diode
Post by: Tumbleweed on 17.07. 2014 19:59

hi , again everybody ,  i have a zener diode in my box of tricks , i wonder if anyone can tell me a simple way to find out if it is neg earth or poss earth, as there are no markings on it and pretty expensive for a new one        thanks  tw

Title: Re: zener diode
Post by: a10 gf on 17.07. 2014 21:52

A little offtopic, but interesting > http://en.wikipedia.org/wiki/Clarence_Zener
More: http://en.wikipedia.org/wiki/Zener_diode

Am learning about 'quantum tunnelling' and 'avalanche breakdown'  lol+++

Title: Re: zener diode
Post by: KiwiGF on 17.07. 2014 21:55

Maybe try 2 x 12v bulb in series and 2 x12v battery in series to see which way it conducts?

Title: Re: zener diode
Post by: duTch on 17.07. 2014 23:06

 Kiwi, why two of each....?
 Maybe you could just do the same with a multi meter...?
Do they come with different voltage ratings..?

Title: Re: zener diode
Post by: wilko on 18.07. 2014 00:22

If it's an original  Lucas one they were only ever positive earth.

Title: Re: zener diode
Post by: Tumbleweed on 18.07. 2014 09:07

thanks everybody , it has lucas stamped on the spade connection so it must be poss earth , thanks again .   tw        ps    that tunnell is a bit too deep for my liking a10gf

Title: Re: zener diode
Post by: a10 gf on 18.07. 2014 09:43

"Either the Zener or the avalanche effect may occur independently, or both may occur simultaneously"
and it seems "minority carriers" are involved.

That should clearly explain it   *smile* +++

(Sorry for the offtopic)

Title: Re: zener diode
Post by: KiwiGF on 18.07. 2014 10:33

heh dutch, zeners have different voltage ratings but for bikes will be designed for 12v regulation albeit there might be one out there for 6v i suppose.

As a zener for 12v regulation would not conduct until over 12v was reached by the genny you need more than 12v to test it.......I think.

Title: Re: zener diode
Post by: Tumbleweed on 18.07. 2014 12:48

i think you are too far in the tunnell  a10gf , i hope you get out ok  *smile*      tw

Title: Re: zener diode
Post by: duTch on 18.07. 2014 13:35

 Ta Kiwi, is just 'cos I don't know if the early unit-const jobbies were 6v, or 12v....or even if they use the same regulation system.
   Other than that, apart from what I read in a10gf 's wiki post that they do flow reverse, I know just a little more than enough to be dangerous... *eek*
 
   a10gf, stay outta those quantunnels- wouldn't like you having an avalanche breakdown- never know where you'd end up...!