If you have searched for Mechanical TV sites on the web you have probably found many beautifully built machines - ones which have taken their builders many long hours to construct. Whilst its true this hobby can easily take over your life - you don’t have to build much to get going. On this page I plan to display a history of my build.
The setup below is essentially how my Nipkow based monitor looked in the summer of 2005. The cardboard disk is driven from a 6v cassette motor via a PWM driver circuit. The LED matrix is based around four 8mm LEDs and is driven by (a not very effective) 2 stage amp made up of 3 signal transistors.
The next photo shows the LED cluster in detail. The four LEDs are connected in series with a 330ohm resistor. The source voltage is 12v which is sufficient to drive them very brightly. The flat bit stuck to the top of them is a scrap of translucent paper which helps to spread the light more evenly. Note at this stage the motor is not even bolted down! Its weight stops it moving about when the disk is spinning.
The sort of pictures this device produced are like
In both cases the picture is suposed to be the letters:
This NBTV logo came from HERE which I burnt then onto an ordinary CD-R.
The next photo dates to September 2005 and shows me starting to develop the viewing system. By rotating the disk backwards (clockwise) and reversing the spiral of holes on the disk I was able to produce a correct upright picture via a mirror. I also used a plastic lens from an old magnifying glass to make the picture bigger.
It was somewhere around this time I upgraded the light source.
This comprised of seven 8mm LEDs of unknown origin. The white wood mount helped to direct the light upwards and the diffuser helped to provide more even illumination. The matrix comprised of a three LED and a four LED string. Both strings had limiting resistors - but the three LED string also had several IN4148 signal diodes in series or else the 2 strings were not of the same brightness.
This design did for quite some while - but in the end was replaced with one using super bright LEDs as it just wasn’t bright enough.
By March 2006 the monitor was looking like this: