A photo electric sensor with a laser.

I plan to use this construction to detect a drop of water falling through the sensor line. It will then be lit up to fool the spectator into believing that the drop of water stays stationary at one point in the air. I use a laser because IR light would pass right through transparent bodies. A laser however will be strayed well enough for such an application.

Category:

Science & Technology

Tags:

• laser
• photo
• sensor
• transistor
• water
• drop
• stationary
• experiment

[linuxgeek81]

I was very tired when I made that vid... and it shows. So please don't mind ;)

[HLSDK]

If you'd like to introduce microcontrollers... Otherwise you could set up a comparator and monostable so the monostable fires at a time after the drop passes through the beam.

Lectures: Are you attending them or giving them? :-D

[linuxgeek81]

Hehe I need the MCU because the fall speed of the water drop is not constant, so we need to do a little calculation after detecting it. That's where all that real time stuff comes in (need to do it fast enough before the drop runs away...).

About the lecture: I suppose a little bit of both... ;p But no, I'm attending it. Unfortunately it's rather boring and the professor hasn't got much hands on experience with that stuff so I try to give at least one real world example of the matter.

[shawnygz]

man like ive said before and i say it again you are a true geek

[linuxgeek81]

Thanks, I guess ;)

Sometimes I still think that in some aspects I don't qualify as a geek. However after seeing some vids around here I thought I'm close enough.

[markas11]

I still do not get why do you want to detect water drop before light flash. Why are you assuming that water drops will occur in so irregular time period. And finally this experiment is just about regularity, this is what it ts about. Do not get complicated.