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Kerr Cell and other light control devices

PostPosted: Thu Oct 05, 2017 8:53 pm
by Harry Dalek
Start a topic here on mainly vintage light control mainly where i left off on pages 34 35 of Steve O's Starting at the beginning with Mirror Screws
viewtopic.php?f=1&t=1379&start=495
So future who ever go there for some other bits on this .
Looking into the dangers of how the classic Kerr cell ended up this PDF has some good information on the dangers of using nitrobenzene .
They seemed to have come in many shapes and sizes .

Re: Kerr Cell and other light control devices

PostPosted: Thu Oct 05, 2017 10:36 pm
by Robonz
Interesting stuff Harry

I found this really good write up on Kerr Cells "kerr_cell.pdf"

I think Kerr cells are basically an early version of an LCD. So you could probably make a Kerr cell by filling it with LCD fluid. You can probably get fluid from a trashed LCD display. This would give you a non explosive version.

Cheers
Keith

Re: Kerr Cell and other light control devices

PostPosted: Fri Oct 06, 2017 11:38 am
by Harry Dalek
Robonz wrote:Interesting stuff Harry

I found this really good write up on Kerr Cells "kerr_cell.pdf"

I think Kerr cells are basically an early version of an LCD. So you could probably make a Kerr cell by filling it with LCD fluid. You can probably get fluid from a trashed LCD display. This would give you a non explosive version.

Cheers
Keith


Yes that's a good PDF Keith the fluid you could experiment with it would work to some degree with different chemicals the first Kerr just used lead Glass perhaps a copy of the Faraday light valve.
I for sure agree any hobby experiments with this idea should use some thing safer than Nitro Benzene ,the good thing with the device is all you have to do using a liquid is pour it out and try another .
I have never really thought about trying one due to the chemical used or a need one as we all use LED'S these days but it is interesting and does have the option of using any type of light .
I don't know of the LCD fluid from a projector is it ? i have not had a chance to scrape one to see what goodies are inside ,sounds like it would have enough ? .
I am just thinking about it at the moment toying with the idea what would be needed to try one if it ever happens .
A vessel of some sort
Prisms i am not sure i have at any great size ,rather track down the polarized lenses this is what would make it workable idea ,have to have a look if i still have them.
Reading up there seems to be no set KV voltage for these due to the different sizes so better to much than not enough ,i think mine can do 10 to 20 KV
would be good to make the EHT supply variable .
I will have a look what i can find laying around it would be a bit of a knock up if it happens ....i would be very interested if others had a go at one as well just for the hell of it ..

Re: Kerr Cell and other light control devices

PostPosted: Fri Oct 06, 2017 12:07 pm
by Robonz
Hi Harry

I was thinking you would get the fluid from an old LCD screen e.g. computer monitor. Easy to find for free or $5. It should have a fair amount of fluid. It also has the polarisers. With liquid crystal fluid you would only need a low voltage. So to get experimenting would be pretty quick and easy. I think copper tape for each plate would work.

Cheers
Keith

Re: Kerr Cell and other light control devices

PostPosted: Fri Oct 06, 2017 7:10 pm
by Harry Dalek
Robonz wrote:Hi Harry

I was thinking you would get the fluid from an old LCD screen e.g. computer monitor. Easy to find for free or $5. It should have a fair amount of fluid. It also has the polarisers. With liquid crystal fluid you would only need a low voltage. So to get experimenting would be pretty quick and easy. I think copper tape for each plate would work.

Cheers
Keith


I will have a look into this if i can track one down i don't have a broken one .
I did play around today and as with all good experiments failure teaches you what not to do :wink:
I had some 3D glasses in case it worked but i was seeing if i could knock up some thing quick .
Had the idea the Faraday one worked with cooking oil
https://www.youtube.com/watch?v=XhU-nNi ... e=youtu.be
Wonder if it would work as in electro static version ...well i had enough voltage checking running my EHT circuit on 12 volts i get 7 kV on 24 volts double that .
I was getting sparking at first and you know what it blew the cork right out of the little bottle with a almighty bang ! lucky for me it was just olive oil :roll: see bottle with cork plates on the bench thats where it ended up !
i removed the cork and spread the plates apart better and got no light valve effect but the particles in the oil were sure bouncing around ...so experiment one bit of a flop but i did get a bang ... :D