fast fun projects?

[Wavebourn]

What projects did you make for fun that can be repeated quickly by other members?

I made a night stand. All took no more that 15 minutes.

Ingredients:

1.) Glass vase
2. )Glass balls
3. )Optic fibers
4. )4 resistors 22 Ohm each
5. )4 LEDs
6. )Old 5V cellphone charger.

Here is the picture attached:

[Cassiel]

A son project.

[popilin]

The only thing pretty fast I can think of is to reproduce the Young's Experiment.

Ingredients

1) A screen (can be used a wall)
2) A LASER pointer (a cheap one)
3) A thin wire (Hey, you must have lots of wire)

Put the wire near the LASER (1 cm would be fine) and on the wall, you will see a beautiful pattern of alternating light and dark bands.

It is one of the most beautiful experiments, and if necessary, you can measure the diameter of the wire with a tape measure, with amazing accuracy, better than with a micrometer.

[Wavebourn]

Thank you Popilin!
But how do you know exact wavelength of the cheap lazer?

[kctess5]

When I'm bored I just pull out the random assorted speaker drawer and through together an OB or something with my extra active crossover, listen to it for a day, decide I still like my system and take it apart

Good fun

But also I like putting LED strip in interesting places, I lined my door frame with some cool white strip and it looks super cool. Took about 10 minutes and was quite cheap

[popilin]

Originally Posted by Wavebourn

Thank you Popilin!
But how do you know exact wavelength of the cheap lazer?

Good point !

I guess standard cheap red LASERs has a typical wavelenght.

Laser pointer - Wikipedia, the free encyclopedia

An other way would be measured with a monochromator.
It also takes less than fifteen minutes.

[adason]

here is one fast and fun...
I took apart old scanner, took out the long fluorescent light tube, hook it up to a small chip amp from computer speakers, feed the little amp with music signal and voila...you get yourself fluorescent signal meter
granted, it has small range, but the light really starts from one end and moves like a bar to the other, fun to watch!

[Wavebourn]

Originally Posted by adason

here is one fast and fun...
I took apart old scanner, took out the long fluorescent light tube, hook it up to a small chip amp from computer speakers, feed the little amp with music signal and voila...you get yourself fluorescent signal meter
granted, it has small range, but the light really starts from one end and moves like a bar to the other, fun to watch!

Did you connect the bulb directly to the amp output, or used it's voltage converter powered from output of the amp?

[tvrgeek]

Originally Posted by popilin

The only thing pretty fast I can think of is to reproduce the Young's Experiment.

Ingredients

1) A screen (can be used a wall)
2) A LASER pointer (a cheap one)
3) A thin wire (Hey, you must have lots of wire)

Put the wire near the LASER (1 cm would be fine) and on the wall, you will see a beautiful pattern of alternating light and dark bands.

It is one of the most beautiful experiments, and if necessary, you can measure the diameter of the wire with a tape measure, with amazing accuracy, better than with a micrometer.

Got to try that. I have a laser level that shroud do just fine.

[adason]

Originally Posted by Wavebourn

Did you connect the bulb directly to the amp output, or used it's voltage converter powered from output of the amp?

i kept the step up transformer between the amp and fluorescent tube, that way I did not have to put volume too high up
there are however such scanners, which have very long tubes without the trafo, just a board with electronics, in that case I connected amp directly