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30 line tin can TeKaDe televisor project

PostPosted: Thu Jul 05, 2012 12:58 am
by aussie_bloke
G'day all.

The other day I enjoyed a good can of casserole for lunch and later in the evening looking at the casserole can I thought to myself, I could make a drum receiver out of it and so I pursued the idea and went ahead it with!:)

I firstly measured the diameter of the can which was 100mm and calculating the circumference it worked out to be 314mm which dividing by 32 lines would give me around 9.8mm distance between holes and wanting the distance to be at least 10mm I opted for 30 lines instead which worked out to about 10.5mm distance between holes. I decided this time to opt for horizontal scanning instead of vertical as I thought suspending the can upside down off a DC motor would me be most ideal so I went for the TeKaDe 30 line horizontal scan format which suits perfectly for this tin can TV. Having the width of the picture at 10.5mm and going for the 4:3 aspect ratio the height calculates to around 7.85mm, so the picture works out to be very very tiny in size for this can! :lol:

I made a 30 line strip template and wrapped it around the can as precisely as possible, sticky taped it in position and using a needle I drilled 30 holes in the tin can and I must say I was surprised how easy and effortlessly the needle drilled through the can! I then precisely as possible drilled a hole in the centre base of the can so it can be mounted on a DC motor.

I next needed to make the can dark and matte as possible to prevent light reflections so I roughed the shiny surface of the can and spray painted it matte black on the outside and inside.

Next I had to choose a suitable DC motor to drive the can, so from a junked CD stereo system I used one of the little DC motors and mounted it onto a piece of bakelite and mounted the can to the DC motor.

Then I made the LED bank which consisted of 4 LEDs, as I had low quantity of brighter LEDs I chose to go funky and use 2 yellow LEDs and 2 green LEDs as I couldn't be bothered going to Jaycar. I then made the hood with diffuser on the end and attached it to the LED bank. On light up the mix of coloured LEDs looks kind of like the floor lights on Saturday Night Fever :wink: .

Next phase of construction is to mount all the pieces together. I used a piece of wood for the base, nailed some wood pieces on the sides of the base to support the bakelite beam with motor and suspended can mounted on it. Underneath I initially cut a plastic avocado dip container base as a bowl to stop the can from wobbling too much on rotation and glued it to the base, unfortunately the can kept catching the edgers and getting stuck so I abandoned the idea and snipped the bowl down lower than the can. I glued the LED bank to the bowl so the can is positioned over it and the LED bank covers the area to be scanned.

In the final construction phase I hooked up the DC motor speed control and LED drive circuits and screwed them to the side wood pieces holding the motor and drum assembly. Being a lazy bugger I decided to once again use the DC motor speed control and LED drive circuits from my very first cardboard mechanical televisor once again.

Now for the testing. I plugged my MP3 play to the LED drive circuit and with MP3 encoded TeKaDe 30 line format videos onboard I gave the tin can televisor a burl and getting the motor to the right speed we have picture wooooot!!!:D As expected it is very tiny almost microscopic so a magnifying glass is needed especially for detailed videos. Also the colour is of a funky blended mix of green and amber which I think looks cool! The picture of course is a bit distorted due to the general off accuracy drilling of the holes in the side of the can and wobble of the can due to the hole in the base slightly off centre but otherwise good considering those factors. So the dang thing works!:D

I have made a video series on the construction of this tin can TV but have yet to edit and upload them to YouTube but when I do I will post the links, so stay tuned for them. In the mean time here's a bunch of photos of the construction of the tin can TV along with a sample telerecording I made with my 90s camcorder:

PostPosted: Thu Jul 05, 2012 4:05 am
by DrZarkov
Congratulations! Good idea, nice done.

PostPosted: Thu Jul 05, 2012 4:50 am
by Lowtone
Brillant :!:

PostPosted: Fri Jul 06, 2012 12:49 am
by Harry Dalek
Great job troy don't think i have seen one of this done on the forum.
Some thing about horizontal scan thats a nice change but glad there are 2 ways to do the same thing .
Keep up the good work .

PostPosted: Fri Jul 06, 2012 9:42 am
by gary
Congratulations Troy, you have made Hackaday: ... /#comments

PostPosted: Sat Jul 07, 2012 11:23 am
by aussie_bloke
Thanks for the great feedback eveyone!:D

What can I say but I am very pleased this project has become a hit and has made it to Hack A Day!:D I can see this post has certainly racked up a good few thousand views too, hope it will inspire others to have a crack at making a tin can TV, it is fun and relatively simple to make and pretty much another exotic way of utilizing the Nipkow disc in the form of a drum which will of course give nice straight images.

I will now have to get my act together and upload those construction Vlog videos of my tin can TV.

PostPosted: Sun Jul 08, 2012 5:03 pm
by DrZarkov
What's really remarkable: Of course many people tried to use a drum instead of a disc. But you achieved a very good result with little effort. That makes it so elegant!

PostPosted: Tue Jul 17, 2012 3:28 pm
by aussie_bloke
G'day all.

I have finally uploaded the videos of the construction work of my tin can televisor from start to finish, it's in a 9 part series and can be viewed via the following links:
Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
Part 7
Part 8
Part 9

I am yet to properly label the videos and write the descriptions but will do so shortly. Also I have made more telerecordings and will upload them soon too and will provide the links.

PostPosted: Sun Jul 22, 2012 5:01 pm
by aussie_bloke
I have now added a couple of telerecordings of my tin can TV in operation they can be viewed through the following links:
Part 1:
Part 2:

PostPosted: Sun Jun 16, 2013 9:41 pm
by aussie_bloke
I've recently decided to refine my tin can TeKaDe televisor so I can make regular use of it so I've decided to replace the green/amber LEDs with my bright white LEDs and make permanent LED/motor circuit for it as I've used the same LED/motor circuit for all my televisors. Having the bright white LEDs in there made the pictures so much better and clearer with greyscales and having the LED/motor circuits on one small veroboard made better for convenience of compactness.

I also decided for a bit of fun to test the tin can TV with my NBTV camera and so I input the camera's video output to the tin can TV and adjust the motor speed to the same as the camera and it worked. Of course being horizontal scan the picture was sideways and being 30 line scan opposed to the camera being 32 line scan the picture rolls, but it was cool to see pictures from the camera on the tin can TV :).

Anyhow next step with the tin can TV is to add a magnifying glass to enlarge the tiny display to a more viewable size and further down the track add synchronization to the motor speed once I've got the motor sync working on the NBTV camera. I have made some vlogs of my refinement progress and will upload them to YouTube and I will also make some telerecordings as well.

Here below are some photos of the tin can TV's refinements and some screen shots:

PostPosted: Sun Jun 16, 2013 10:07 pm
by aussie_bloke
The last two pictures displayed on the tin can TV are from my NBTV camera filming that Seize Power energy drink can with Che Guevara's face on it, one being inverted video and the other normal.

PostPosted: Tue Jun 18, 2013 6:11 pm
by Harry Dalek
Good work Troy i like the TeKaDe system for drums having the drum rotating on the horizontal is a lot easier than on the vertical Baird system i wonder too if this makes wobble problem less so, the new lighting is much better .

Due to what its made of it could take more heat of if you had an arc lamp and a lens it would make a nice projection tv over come the tiny picture size .

I found on the flying spot scanner idea using a good powered laser defocused you could do the above with modern day device .

Viewing off a lens might also be a nice idea too for a larger picture size if you end up housing it more than likely the easiest idea .

But again good work its great to see different types of televisors more the better .

PostPosted: Fri Jun 28, 2013 8:20 pm
by aussie_bloke
Some further developments to my tin can TV, while I was developing a lens system for my Iconoscope camera and have found that 3 magnifying glass lenses shortens the focal distance, I also found that I got triple magnification when magnifying objects in close range and I thought this would be an excellent idea for enlarging the tiny 10mmx8mm picture on my tin can TV so I put it to the test and it worked beautifully! :D I have the lenses positioned 65mm from the display and the picture is triple magnified to a much more watchable size. I am now in the process of securing the lens and enclosing it and the tin can to keep out stray light. Here below are pictures of the tin can TV and its lens and some screen snaps, as seen in the greyscale bars it has good greyscale gradation in light levels: