Corona Discharge lighting

[Harry Dalek]

did some more web sufing and found this on a different form lighting ...using what i gather is sort of like hooking up a EHT coil to the amplifier interesting that'll keep your fingers in your pocket when you switch it on ....looks like it sparks to the disk

i think i'd have it between glass now theres a project for us modern day inventors

[dominicbeesley]

That looks interesting...are you going to give it a go?

Dom

[Harry Dalek]

That looks interesting...are you going to give it a go?

Dom

Hi dom

i like the idea of it but connecting it to a lamp or a broken Incandescent should give the same effect i think , or is that now a cracker lamp ? either case hes sounds like it worked and much better than a neon lamp.
I am wondering if a normal 15khz eht transformer circuit could be modulated to give the same effect maximum voltage would be the feq it runs at so that would give the brightest just and not sure of the lowwer end ...there would be a few ways to control it.

On my 240v audio light modulator

I was hoping my triac circuit would do it but i think the 60hz ac that it uses is the problem.....i tested it with a 3watt luxeon 240v downlight its a bit better than the fluo but you can tell theres still a loss in nbtv signal .

I am not too sure yet if i am right but theres only 2 things it could be first
its not switching fast enough because its only using 60hz or its the electronics in both lamps ....i think its the 60hz i was thinking of using a lowwer voltage eht type circuit running at a higher feq so it would switch on and off faster that would give it a wider band bandwidth i'm thinking

[dominicbeesley]

It's not switching fast enough.

The NBTV signal needs roughly 10kHz of bandwidth to look sharp. With 60Hz you're giving it roughly 60Hz of bandwidth.

i.e. as the light scans along the raster it needs to be able to go on and off 10,000 times a second. With a triac, once it's switched on it won't switch off until the next 60Hz crossing....

Dom

[Harry Dalek]

The crater lamp
Now this looks like one bright lamp !

[Harry Dalek]

It's not switching fast enough.

The NBTV signal needs roughly 10kHz of bandwidth to look sharp. With 60Hz you're giving it roughly 60Hz of bandwidth.

i.e. as the light scans along the raster it needs to be able to go on and off 10,000 times a second. With a triac, once it's switched on it won't switch off until the next 60Hz crossing....

Dom

Thanks dom

this answers what i was thinking it was ....I think if i could be run at the faster freq it might just work which isn't that hard to do .

I will work on this !

[Steve_McVoy]

Here is more:

http://www.earlytelevision.org/images/rayphoto.pdf

[Harry Dalek]

Here is more:

http://www.earlytelevision.org/images/rayphoto.pdf

Hi steve
Thanks very much for linking this !
very interesting and i wasn't sure how to make one but after reading this
its pretty much all there how it was done plus more !
theres stuff in this pdf i think a lot of nbtv people would not have know was about like me !
For me this is a gold mind.

[Harry Dalek]

Having a good read of steve upload becomes pretty clear how this works
i find it really interesting , viewing a nipkow via a viewing screen is unheard of these days so if its doable disk sizes drop and higher line rates will go up for us ....
I just finished a nipkow as a test disk for other projects i think i will look into making a moden day version, i can see it working in the plate and needles as it rotates its in sync as it dischages using as lamp to dischange in might just be the same as using a Led the needle plate idea to me sounds like it would work better but more dangerous but would i think need less sync control ? mmmmm clever buggers back then .
I have never tried to spark a eht very close i know it bright but is never blinding light as i recall as a few mm apart ....this project sounds like tesla meets baird.

[Harry Dalek]

Hes a pdf on early tv and a system using corona more fax pre live tv me thinks and other stuff a lot going on in those days

[Steve_McVoy]

Harry, do you have the October and November issues of that magazine, that have the rest of the articles about Rayphoto?

[Harry Dalek]

Heres the gold mine link !i havn't downloaded them all but looks like there would be some nice vintage stuff on early television if issue 12 1927 is any thing to go by.Love PDF !
OH the bliss ! vintage electronics

http://www.vacuumtubeera.net/RadioBroad ... azine.html

[Harry Dalek]

Harry, do you have the October and November issues of that magazine, that have the rest of the articles about Rayphoto?

Oh sorry i just found the link to the magazines so i am downloading them as i think you will be as well