Non-electric Television.

Forum for discussion of narrow-bandwidth mechanical television

Moderators: Steve Anderson, Dave Moll, Andrew Davie

Postby Stephen » Sat May 19, 2007 8:04 am

Klaas Robers wrote:Why do you want to use Stirling Engines? Isn't it much easier to use a steam engine? You will have much less problems in getting enough torque using a steam engine than with a Stirling Engine..... I know Stirling Engines, I have two of them. They are difficult to start up, while a steam engine just runs.
Steam sounds good to me, Klaas. Somewhere in this thread we just started discussing hot air/Stirling engines. Perhaps we were trying to keep the system "green" as possible. We do not want these non-electric television systems to contribute to global warming!

Anyway, I like the idea of having plenty of drive torque and a steam-driven pneumatically-synchronised system sounds like the way to go. Thanks for the suggestion.
Stephen
User avatar
Stephen
Anyone have a spare straightjacket?
 
Posts: 427
Joined: Fri Jan 26, 2007 7:00 am

Water powered television.

Postby Stephen » Sun May 20, 2007 12:27 am

I was just thinking...what if we forget about steam and just couple two hydraulic motors in series, one for each scanning disc, and have water from the mains drive them? Just turn on the tap and the camera and display discs rev up.

Then I was thinking that water in a plastic delivery tube between the motors could serve as a light pipe to replace the optical transmission fibre. It may not be as efficient, but a single stream of water would then serve as both the power supply and the communication channel.

Each end of the water delivery tube would couple into a container with an optical window on the end of it. A lens would couple light between the scanning disc and the water delivery tube through the optical window. The water in each container could flow through an aperture in its side to couple to the hydraulic motor to drive the scanning disc.

I think that the first use of a stream of water as a light pipe was with the lighted water fountain jets at the Crystal Palace during the 1851 Exhibition.
Stephen
User avatar
Stephen
Anyone have a spare straightjacket?
 
Posts: 427
Joined: Fri Jan 26, 2007 7:00 am

Postby Viewmaster » Sun May 20, 2007 12:54 am

[quote="Stephen]Steam sounds good to me, Klaas. Somewhere in this thread we just started discussing hot air/Stirling engines. Perhaps we were trying to keep the system "green" as possible. We do not want these non-electric television systems to contribute to global warming![/quote]

Go real 'green' and use a windmill. Come to think of it a windmill with 32 sails with round scanning holes near the axis makes a Nipkow....a Nipkowmill.
Notice.."Do not adjust the sync on your set,
as the wind will pick up soon." :)

Albert.
User avatar
Viewmaster
Frankenstein was my uncle.
 
Posts: 1289
Joined: Fri Apr 06, 2007 4:50 am
Location: UK Midlands

Fluidic television.

Postby Stephen » Sun May 20, 2007 1:32 am

Yes Albert, I think the windmill is a fine idea. The windmill may drive a water pump that in turn drives the series connected hydraulic motors in synchronisation. The beautiful thing is that as long as the discs are spinning fast enough to have a usable frame rate, they need not have a constant angular velocity. They could vary between 20 and 100 fps or more depending on water flow and since they are series synchronised they stay in step.

Full colour, ecofriendly fluidic television---I am going to have to write up a newsletter article.
Stephen
User avatar
Stephen
Anyone have a spare straightjacket?
 
Posts: 427
Joined: Fri Jan 26, 2007 7:00 am

Postby Viewmaster » Sun May 20, 2007 1:45 am

Not forgetting using wave power for NBTV at sea! :wink:

Also rotating Crookes Radiometer's discs when the Sun is out. They rotate near to 400 RPM. Speed control by movable shield to cast part shadow on the disc.....the Crooked Nipkow. :lol:
Albert.
User avatar
Viewmaster
Frankenstein was my uncle.
 
Posts: 1289
Joined: Fri Apr 06, 2007 4:50 am
Location: UK Midlands

Re: Water powered television.

Postby Roland » Tue May 22, 2007 11:05 am

Stephen wrote:I think that your optical fibre drum project in itself is just as exciting as the non-electric television experiment.


I quite agree and even if non electric TV proves impractical - the fibre scanning units should still prove interesting/useful.

Stephen wrote:I was just thinking...what if we forget about steam and just couple two hydraulic motors in series, one for each scanning disc, and have water from the mains drive them? Just turn on the tap and the camera and display discs rev up.


Fair point. I've been thinking about your suggestion for hydraulic motors over the weekend and I do like the idea of using identical displacement for synchronisation.

Instead of water though - I was thinking that (at least in the UK) - every middle class family who was anybody would have had gas piped into the house. Possibly such a system could have been run of gas pressure. There wouldn't be any actual link between the camera and the monitor just an understanding of what gas presure they both would use.

Okay - so I wouldn't actually use gas to demonstrate this (!) - but maybe drive the camera and monitor from the same air compresser.

I still favour attempting to use a Stirling engine - but only because they seem safer and easier to build than steam ones.

:-)

Roland.
Roland
Master Craftsman
 
Posts: 56
Joined: Wed Feb 21, 2007 11:56 am
Location: Hampshire, UK

Postby Klaas Robers » Tue May 22, 2007 9:46 pm

Oh Roland, have you ever tried to use an old compressor from a refridgerator as an air compressor? That works fine and silent. Then you have compressed air everywhere where there is a 230V power outlet. This makes the non electric NBTV useable at many more places, e.g. at the venue of the convention.
User avatar
Klaas Robers
"Gomez!", "Oh Morticia."
 
Posts: 1512
Joined: Wed Jan 24, 2007 8:42 pm
Location: Valkenswaard, the Netherlands

Fluidic television.

Postby Stephen » Wed May 23, 2007 2:51 am

I was just thinking that fluidic television, that is, using a stream of water as a light guide and possibly even a power source, could have been done well before the nineteenth century. Even the ancient Romans had lenses, which they called “burning glasses”, that they would use both to concentrate sunlight to ignite a fire and for magnification purposes. Engravers commonly used them in their work. They knew how to draw glass into fibres. They had indoor plumbing, aqueducts, water wheels and knew about Heronas' steam engine, the "aeolipile", and Ctesibius' air and water pumps. In other words, they had all the components to fabricate a working fluidic television system.

It would not surprise me to find out that archaeologists are pondering the significance of ornamental centre-punched brass disks with spirals of gemstones that they find in the ruins of ancient Roman households, sometimes even two or three to a household. They seem to have some connection with a gifted Roman engineer by the name of Logius Bairdius who first introduced them in the 20s --- AD, of course. They are similarly confused by the listings of hourly plays that they find in such households, presumably for the local theatre –-- interspersed with news reports.

The declining attendance at the Coliseum and the fall of the Empire may have been due to a factor that they have yet to discover.
Stephen
User avatar
Stephen
Anyone have a spare straightjacket?
 
Posts: 427
Joined: Fri Jan 26, 2007 7:00 am

Distribution system for non-electric television - 1880.

Postby Stephen » Wed May 23, 2007 9:24 am

I just found an interesting patent. An American engineer by the name of William Wheeler applied for a US patent relating to a lighting system for a dwelling that could use a single arc light. It would distribute the light to individual rooms by means of internally reflecting light pipes! This is the same principle for light transmission as we have discussed for non-electric television that Mr. Wheeler proposed back in 1880 for general lighting purposes.

I have placed a copy of Mr. Wheeler's patent in the Patent and Articles section of the forum for reference. It is US Patent 247,229, filed 10 December 1880.
Stephen
User avatar
Stephen
Anyone have a spare straightjacket?
 
Posts: 427
Joined: Fri Jan 26, 2007 7:00 am

Postby AncientBrit » Wed May 23, 2007 11:00 pm

Stephen,

I like that!

Cheers,

GL
AncientBrit
Green padded cells are quite homely.
 
Posts: 858
Joined: Mon Mar 26, 2007 10:15 pm
Location: Billericay, UK

Postby Roland » Wed May 23, 2007 11:29 pm

Klaas Robers wrote:Oh Roland, have you ever tried to use an old compressor from a refridgerator as an air compressor? That works fine and silent. Then you have compressed air everywhere where there is a 230V power outlet. This makes the non electric NBTV useable at many more places, e.g. at the venue of the convention.


Yes - of course there are many more practical choices for driving the compressor than a Stirling engine - and assuming I ever do make it to the convention (I can always dream) a 230v solution would be ideal.

Anyway - its made me think of model engineer exhibitions where I have seen steam engines running off compressed air. Assuming compressed air is used instead of steam - a couple of identical steam engines (or similar) would seem to be ideal for this project.

:-)

Roland.
Roland
Master Craftsman
 
Posts: 56
Joined: Wed Feb 21, 2007 11:56 am
Location: Hampshire, UK

Postby Stephen » Thu May 24, 2007 12:06 am

Roland wrote:Anyway - its made me think of model engineer exhibitions where I have seen steam engines running off compressed air. Assuming compressed air is used instead of steam - a couple of identical steam engines (or similar) would seem to be ideal for this project.
Yes, I think that small steam engines running off compressed air would work very well and add more of a 19th century flavour than modern air motors could do. Since steam engines are piston driven positive displacement devices they should work fine in series as a synchronous pair. As a way to eschew electrons away from home, an air tank could serve as a source of pressurised air for portable use.

I understand that glass fibre as thin as ordinary thread was available for manufactured articles, such as lampshades, filters, bandages and even articles of clothing as early as 1892. It seems that no one thought to use a such glass fibre as a light guide at the time.
Stephen
User avatar
Stephen
Anyone have a spare straightjacket?
 
Posts: 427
Joined: Fri Jan 26, 2007 7:00 am

Postby Dave Moll » Fri May 25, 2007 12:33 am

Apologies if something has already been said and I've missed it, but has anyone come up with any sort of method for taking this experiment beyond the confines of CCTV? I love the idea of transmitting by light pipe (which has a lovely combination of 19th and 21st century feel about it), but would like to be able to receive the picture remotely.

The nearest my mind can get to this is to place the output of the light pipe at the focus of a parabolic mirror - with a similar setup within line-of-sight to receive it. I suspect that the losses therein would be too great to achieve any useful distance.

On the subject of synchronisation, would it be possible to drive both camera and receiver discs from the same compressed-air supply? The CCTV link would then consist of a light pipe and an air pipe.

Edit: A further thought - to avoid the use of electricity for creating the air supply, perhaps the air compressor could be operated by pedal power.
User avatar
Dave Moll
Just nod and pretend you understand me
 
Posts: 396
Joined: Tue Feb 27, 2007 9:11 am

Optically beamed non-electric television.

Postby Stephen » Fri May 25, 2007 1:41 am

Dave Moll wrote:The nearest my mind can get to this is to place the output of the light pipe at the focus of a parabolic mirror - with a similar setup within line-of-sight to receive it. I suspect that the losses therein would be too great to achieve any useful distance.
Great idea, Dave! Now we can expand the discussion to "beamed" non-electric television! I think that it could work with large parabolic reflectors. It might even work as well as transmitting optical signals over the same distance through optical fibre.

The only real issue that I see with beamed non-electric television is synchronisation, but that is a small point.

Dave Moll wrote:On the subject of synchronisation, would it be possible to drive both camera and receiver discs from the same compressed-air supply? The CCTV link would then consist of a light pipe and an air pipe.

Edit: A further thought - to avoid the use of electricity for creating the air supply, perhaps the air compressor could be operated by pedal power.
We have suggested driving the camera and display discs with pneumatic motors in series driven by the same compressed air supply to achieve synchronisation. That is, a compressed air supply would drive the camera disc motor, the discharge of the camera motor would feed the inlet of the display motor and the display motor would discharge to atmosphere.

The air pipe between them could also serve as the light pipe if it has good internal reflection qualities, similar to the light pipe arrangement shown in Mr. Wheeler's 1880 patent. In this case, each end of the air pipe/light pipe would terminate in a container that has an optical window on the end and an air fitting on the side. A lens would couple light between the scanning disc and the air pipe/light pipe through the optical window.

A steam engine or Stirling engine could run an air pump to supply compressed air, but a treadle-powered air pump would be an interesting choice as well.
Stephen
User avatar
Stephen
Anyone have a spare straightjacket?
 
Posts: 427
Joined: Fri Jan 26, 2007 7:00 am

Previous

Return to Mechanical NBTV

Who is online

Users browsing this forum: No registered users and 3 guests