LED indicator light for electric shock fence

[PDA123]

I want to make an LED indicator light for the electric shock fence that surrounds my garden.

The fence pulse voltage is 6000vac.

I have a bunch of 3v LEDs.

So the theory is this;

6000 - 3 = 5997 vac

5997 / .025 = 240k Ohm resistor

The problem is sizing the diode! I don't know what to use.

Any suggestions?

Thank you,

Peter

 

[danadak]

I would be moré inclined to wrap a couple of wire turns around the fence wire
to create a transformer and get the fence pulse that way. Eliminates concerns
over fence V arcing over the R, and mitigate transients that exceed reverse LED
V spec limits. Use teflon wire, even car spark plug wire, to insure no arcing to led
circuit.

Regards, Dana.

 

[PDA123]

Using the idea of a loose transformer, as you mentioned, would it be sufficient to use a 1N4007 diode?

Thanks,

Peter

 

[MaxHeadRoom78]

I would investigate a neon lamp device, at that voltage, you do not need hard contact.
They light at extremely low currents.

 

[PDA123]

I'm trying to keep this as cheap as possible. Neon are about $5 in the US....and I don't have the patience or desire to purchase from China.

Well, maybe I can get one of those Harbor Freight test lights?

 

[danadak]

Using the idea of a loose transformer, as you mentioned, would it be sufficient to use a 1N4007 diode?

Thanks,

Peter

Yes on the LV side of the transformer that should be ok. Ideally you should be
developing a LV on turns around fence wire. Maybe (ignore deep math) this might
give you some clues -

13.7 Applications of Electromagnetic Induction – University Physics Volume 2

pressbooks.online.ucf.edu

There is a general topic called "joule thief" where folks are robbing small amounts (typically) of
power from various sources to power low power circuits. Worth investigating.

Neons do in fact need very little power. Modern LEDs, many visible also in uA range.
But generally you think about 1 mA or better.


Regards, Dana.

 

[Lightium]

I'm trying to keep this as cheap as possible. Neon are about $5 in the US....and I don't have the patience or desire to purchase from China.

Well, maybe I can get one of those Harbor Freight test lights?

Bulbs go for 49 cents here.

https://www.mouser.com/ProductDetail/Lumex/GT-NE4H1125T?qs=0JU57JYmZjvLEdMpBEDnkg%3D%3D

 

[tepalia02]

You can use something like this:

 

[Reloadron]

I would investigate a neon lamp device, at that voltage, you do not need hard contact.
They light at extremely low currents.

While late I would look into this or find an old short thin fluorescent light tube and much like neon just place it close to the HV fence wire. The gas should ionize and done.

Ron