Television Machine with 4 LED – Stripes (Fernsehbild mit LED – Leisten)
____________Television_____ ____________in a extraordinary__ ________________way._______ Today we even have a record theme. In the Guinness Book you find a Television – Machine here. We have this unique TV-Machine here in our studio. This is the new tv-set. It looks like a reaper (for grain). Here we have LED – stripes. 4 stripes are necessary (required) for this system. Here the electronics. And … above all we can introduce the inventor of this machine. Mr. Peter Schmalenbach, electrical engineer from Neuwied, Germany. You came to us with your TV – machine, which was built by a lot of spadework (much detailed work). I find it fantastic that you had thought: TV-Sets are well-known, but now we make the screen in a completely other way. Are you a little Nipkow who had invented the television with his hole-disc in those days (1884)? No, I’m not. But since my youth I’m very interested in electronics, electrical engineering, radio and television sets. I wanted to see whether it is possible to make a television image (screen) with LEDs. You have used light emitting diodes (LEDs) because they are very quick. You have here beside your device a conventional tv-set. What for? Why? This tv-set supplies the signals / impulses for my device. But we could use any video-source (recorder, player etc.). This box is for improvement and preparation of the signals. Power supply units. The control desk for the big step motor (stepping motor). A stepping motor is very well suitable to hold the television image (screen) in its position (vertical hold). By using a stepping motor a controlling loop (regulation) is not necessary. The step motor drives this in a controlled system. The whole television signal is given to these LED – stripes. I hope that we already can see here some brightness modulation. Each LED – strip (line) gets the complete television signal. Now we only have to separate the lines (the lines have to diverge). And that makes your machine by rotating. Please explain a little bit this electronics. This is a big shift – register (232 bit). That shift – register switches 232 transistors (one after another) and the transistors switch on the LEDs (according to the tv-signal). 232 LEDs in 1 stripe (4 stripes existing). All stripes have the same signal. For each image point there is a field effect transistor and a sample and hold circuit. So the video signal is held for a short time with the help of a capacitor. The value of the brightness for each image point is stored for the duration of a line (64 microseconds). The video signal is very quick. Therefore we have to store the momentan-value of the signal for a short time. We have to do this for each image point in a line. This was the theory. Now it comes to the practice. Here we go! We start now! Put on the helmet! The thing also makes a lot of noise. We have to dim the light to see better. Attention! There is coming the first image! These images have now the half of the maximum screen height (image height). The number of revolutions per second is 6.25 When the number of revolutions is 12.5 per second, then we can see the full television image (full height). 4 stripes • 12.5=50 images (pictures) per second Now the turbo effect comes. The machine turns higher and higher (rotates faster). I must increase the speed slowly. Otherwise the step motor cannot follow. If this would become our new tv-system we would need other remote controls. …with buttons for synchronisation and rotation speed + / – … So … yeah … now we come closer. Now I can synchronize the system by a switch. The image (screen) has a standstill then (=vertical hold). TV station (camera) and this machine are now clock-synchronous (in strict time). I change to some other TV stations (channels). Now we have a test pattern and can see the teletext signals above (videotext). Can you improve brightness and the contrast? We see “Hessen 3” (=TV station) at the moment. … other tv stations … RTL=Radio Television Luxembourg So, in any case, definitely, this device can produce the television image (tv screen) and show the program. There you can see it very good. We should turn on the light again and slow down the speed. Super! Fantastic! You should build a protection cage around. Yes, we have to watch out and to be careful. Especially protect your fingers! Mr. Schmalenbach, now you have 232 LEDs in 1 line (stripe). Have you the intention to build this for color television? Did you think about this? Yes, that is possible. But the expenditure and the working time is 3 times as much as the construction of this machine here. Then you need red, green and blue LEDs. And blue LEDs are still very expensive (1992). If the costs of the LEDs would be low, would you construct a color television machine then? Yes, I would do it. The mechanical construction is no problem. But adjusting (tuning) the electronics lasts for a long time. Surely you didn’t want to change our television system by your invention? No, that was more a fun. And it was very interesting for our apprentices (trainees). But what you can do here very easily – all are talking about HDTV: You only would have to lengthen the stripes – expand the strips and mount more LEDs – and you have HDTV (format 16:9). A new picture-tube (CRT) would be more expensive. The size and the definition (sharpness) of the screen are changeable easily. Do you see it more as a work of art or a performance? Both. And also as an experiment. You should go to some exhibitions (fairs) with this device. I find it very good that someone during his leisure-time thinks about another tv system and says: I make it in another different way. Thank you very much for coming in our studio.