Author Topic: Zener Diode + Earth  (Read 233 times)

Offline A10 JWO

  • Resident Legend
  • *****
  • Join Date: Oct 2012
  • Posts: 695
  • Karma: 2
Zener Diode + Earth
« on: 19.06. 2019 15:12 »
Everyone seems to be out of stock of these important items, even Draganfly don't seem to hold out any hope. Has anyone on here know different please. Thank you.

Online Greybeard

  • Jack of all trades; master of none.
  • Wise & Enlightened
  • *
  • Join Date: Feb 2011
  • Posts: 5474
  • Karma: 29
Re: Zener Diode + Earth
« Reply #1 on: 19.06. 2019 17:49 »
RS, (Radio Spares) list 5743 Zener Diodes. Wouldn't they have something suitable?
You will probably have to build it onto a heat sink of some kind.

Online Triton Thrasher

  • Scotland
  • Wise & Enlightened
  • *
  • Join Date: Feb 2009
  • Posts: 1420
  • Karma: 20
Re: Zener Diode + Earth
« Reply #2 on: 19.06. 2019 21:19 »
They’re not important items if you use something else.

Online beezermacc

  • Resident Legend
  • *****
  • Join Date: Dec 2011
  • Posts: 865
  • Karma: 34
  • Not for the purist!
    • Priory Magnetos Ltd.
Re: Zener Diode + Earth
« Reply #3 on: 19.06. 2019 23:15 »
What do you need it for?
Priory Magnetos Ltd - A10 spares, magneto and dynamo refurbs. www.priorymagnetos.co.uk

Offline A10 JWO

  • Resident Legend
  • *****
  • Join Date: Oct 2012
  • Posts: 695
  • Karma: 2
Re: Zener Diode + Earth
« Reply #4 on: 20.06. 2019 22:20 »
It's for a 500 Triumph 1963. I was given a Diode today, how do I test it with a basic Fluke Meter please. Just fitted a new Lucas alternator and want to make sure all is well. Thanks.

Online chaterlea25

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 3067
  • Karma: 45
Re: Zener Diode + Earth
« Reply #5 on: 20.06. 2019 23:33 »
Hi A10 JWO,
Testing with a Fluke it will /should behave just like a normal diode, OL when connected one way and showing 0.4- 0.6v
the other
To test properly you need a variable DC supply
Fit it to the bike and measure the battery voltage with the engine running,  on revving the engine the voltage should not exceed 14.7v
Old Zener's go dodgy and the voltage threshold rises with age
A modern rectifier /regulator is a better option in this day and age

John
1961 Super Rocket
1963 RGS (ongoing)

Online Rex

  • Valued Contributor
  • ****
  • Join Date: Apr 2017
  • Posts: 433
  • Karma: 0
Re: Zener Diode + Earth
« Reply #6 on: 21.06. 2019 08:02 »
Agreed, though if you want to use a new Zener why not just convert the bike to -ve earth?

Offline A10 JWO

  • Resident Legend
  • *****
  • Join Date: Oct 2012
  • Posts: 695
  • Karma: 2
Re: Zener Diode + Earth
« Reply #7 on: 21.06. 2019 15:26 »
So if I have 15 volts at the battery with the engine running, would it be the solid state rectifier at fault or the Zener not doing it's job, thanks.

Online chaterlea25

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 3067
  • Karma: 45
Re: Zener Diode + Earth
« Reply #8 on: 21.06. 2019 21:16 »
Hi A10 JWO,

Zener not doing it's job

A too high voltage will harm the battery and electronic ignition unit if fitted

John
1961 Super Rocket
1963 RGS (ongoing)