Baird-style Televisor

Recently, about the 3rd or 4th of January, I started a new project - to build a working Baird Televisor. After an afternoon, I had the motor and Nipkow disc working (spinning round :p ), and the next day I built a small case for it... out of BALSA! The machine is about 5 inches high, 3 wide, and 1 1/2 to 2 thick, and it has a picture that is 1/2 of an inch wide by one inch high. LARGE! Soon after, I think it might have been a couple of days later, I got some other parts and completed it.

(What it looks like from the front)

How I built the machine:

First, I got a small piece of black plastic, and cut it to be a disc of about 2 2/3 inches in diameter. With a small pin, I scratched some guide lines into the disc, one first, then another perpendicular, then another between etc... until I had 8 pairs of lines/16 lines. Then, I poked 16 small holes into the disc, each time a little further in than the last. Finally, I poked a larger hole into the centre of the disc so that I could slot the spinning bit of the motor into it.

Now I had a working Nipkow disc, and I was ready to do the next part; a lightbulb. I got a very small Christmas tree-type lightbulb and soldered wires to each terminal, then I used superglue to stick a small piece of wood (from the end of an incense stick :p ) to the motor, and then the lightbulb to that, hanging it just behind the holes, where the picture would be formed.

Next, I had to build a case for it. I made a small box out of balsa wood, and cut a small square hole for the picture, and stuck a small piece of clear plastic on the inside of it, and then I mounted the motor-and-disc-and-lightbulb arrangement into the box, using three pieces of balsa that I had stiffened with superglue and paper; one down the side, one on top, and one underneath. Then I had to varnish the outside of the case.

Then, I just had to build the amplifier, which I did using a generic Darlington transistor arrangement, and connect it into the power and the lightbulb, and I wired up the power input terminals to a 3.5mm mono earphone jack plug, and the input, where the signal goes into the amplifier, to a 3.5mm earphone jack socket, to plug whatever outputs the signal, perhaps a dictaphone or a CD player. Now I wired up a second jack socket to a 9-volt battery plug, to make a power socket into which I could plug the televisor's power supply plug.

Inside the thing (As you can see, the inside is a rotten mess...)

Things to do in the future:
In the future, I will be building a larger machine, which will use a Baird-standard disc (30 lines instead of 16), and I will use a more powerful amplifier circuit, a rheostat to control the speed of the spinning Nipkow disc, and a second signal input and amplifier arrangement, for a built-in speaker. Perhaps I might even build in the radio tuning circuit as well.

However, recently, I found copies of Paul Nipkow's original designs for the disc arrangement, and so I will, before doing anything else, be building my own interpretation of the Nipkow Televisor.

Specification (Camera)

1 3" 18 hole disc
18 line camera based on standard photoelectric (solar) cell
Monochrome
Spin at 10RPS
Connect to low power AM transmitter?

Specification (Display)

1 3" 18 hole disc
18 line display based on standard low voltage lightbulb
Spin at 10RPS

New Thought
I've just had another thought. I could make the machine so that I can swap the solar cell in the camera with a lightbulb, making it into a display. Instead of trying to transmit a signal, I could start off by simply recording it into the computer as an MP3 file (I will upload such files as they are created), and then play it back into the display after swapping the components. I will also, when I have all the parts, post the exact specification of the machine so that you can have a go at building a copy of the machine yourself (you might find the MP3 signal recordings handy for testing it). I will get back to you.