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Home: Garden: Water
Watering Can Strobe Light   (+30, -2)  [vote for, against]
water plants and strobe the drops

Night watering of plants is a good idea (I'm told), but then illumination becomes a slight issue. Rather than just attaching a spot lamp to the watering can, why not cross the line into halfbakery land and make it an adjustable strobe light which illuminates the drops as they descend?

Now you can watch the drops "freeze frame" as they fall, and treat any nosey neighbours to a free-light show.

Wearing a white lab coat; taking notes on a clip board; jotting down times; adjusting the frequency of the strobe, whilst muttering some form of mumbo-jumbo, will add to the effect.

Watering Can Strobe Light is available in a variety of colours and comes with a variable "hum". (epilepetics should be wary)
-- xenzag, Jul 04 2010

(?) Sort of like this. http://www.phys.unc...ipe_flashlight2.jpg
Only better. [MaxwellBuchanan, Jul 04 2010]

Sort of like this. http://1.bp.blogspo...0/pour-lighting.jpg
Only wetter [2 fries shy of a happy meal, Jul 05 2010]

(?) Harold Edgerton http://web.mit.edu/...t/iow/edgerton.html
Inventor (or at least popularizer) of the Strobe Light [csea, Jul 07 2010]

Strobe Light Kits http://www.goldmine...ducts.asp?dept=1281
Mostly Xenon, at least one LED type [csea, Jul 07 2010]

great idea - and there's always potential for a Van der Graaf generator attachment
-- hippo, Jul 04 2010


If you adjusted the strobe so the droplets appeared to rise into the spout, then you could save yourself a trip to the tap to refill the can!
-- pocmloc, Jul 04 2010


I wish you'd do this xenz. Totally patentable, utterly charming and a great idea.

Bet people would buy 'em.

I'd buy one and I hate plants. I don't even like eating them.
-- doctorremulac3, Jul 04 2010


[+].

For maximum effect, place the waterproof strobe inside the can, so that the emerging water acts as a light-pipe.

[link]
-- MaxwellBuchanan, Jul 04 2010


I would call that The Maradona effect.
-- xenzag, Jul 04 2010


I think a few people are over-estimating the effects of a strobe.

Firing a strobe at falling water droplets will appear to freeze each drop for a fraction of a second, but there won't be time for your eye to register much of anything. If the next drop is coming in at exactly the same place at exactly the right time for the next flash you might have something, but only a carefully-calibrated dripper and synchronized strobe will give the illusion of a drop suspended in air or backing up into the can, and a watering can just doesn't deliver that kind of consistent drippage.

The light pipe might be interesting, but when the droplets form the effect will be pretty much wasted. Still, it would be sparkly at the nozzle.

I would like to see a long-exposure shot of a sprinkler-can's output, lit only by repeated strobe flashes. It would look like an immense cloud of suspended droplets, some intersecting with each other.
-- baconbrain, Jul 04 2010


It should be possible to measure droplet formation and synchronize to "freeze frame" or slowly precess the image forward or backward.

Years ago, this would have required high voltage and a xenon flash tube, but today's high power white LEDs are quite up to the job. Should be able to run on a couple of AA cells in the handle.
-- csea, Jul 05 2010


[Bacon] - this could be easily done with control over the strobe frequency and duration. A simple variable frequency PWM driver for a bulb or LED could do it nicely. Trim the frequency knob until the drips look suspended, then trim the duty knob to get the crispest image. For a reasonably constistent spray velocity (easily done with pressure regulated sprays) - this should work great.

The really cool thing is the velocity of the drops would change as they flew through the air. I imagine that when tuned in, you'd get the middle of the spray arc looking like it's suspended in the air. Back towards the nozzle of this middle point it would look like the drops were accelerating back into the sprinkler. Further towards the lawn, the drops would accelerate into the ground.

[unless my logic is totally faulty] bun bun bun
-- Custardguts, Jul 05 2010


This is just great. Excellent. Maybe also fit a small smoke/dry ice machine to your can, to complete the look.
-- calum, Jul 05 2010


To make the strobe thing work, the rate of emmission of droplets would need to be synchronised with the strobe, and their trajectories controlled so that each followed the same path as the last.

I'm sure electronic fuel injectors could be adapted to this purpose. With an array of injectors and a synchronised strobe, you could create endless patterns in the droplets, e.g. making an individual droplet appear to hang in space while others appear to dance around it.
-- Twizz, Jul 05 2010


Very good. If you bake it, they will buy.
-- 2 fries shy of a happy meal, Jul 05 2010


Can we get it to play muted "Rave" music so that I can relive my youth and imagine I'm out in the middle of a field going mental, whilst only really being in the garden watering the geraniums in my slippers?

(That's the problem with geraniums, blimmin' slipper thieves!)
-- zen_tom, Jul 05 2010


As [Twizz] says, the emission of droplets would need to be regular. A watering can has no emission control, it is just random. So maybe I should have said that folks are overestimating the precision of a watering can.

I searched YouTube for "strobe droplets" and found descriptors that all lead with emission control..."The water drops out at a regular rate", "The drops are produced regularly by a vibrating nozzle", "Using a reciprocating pump .. This illusion is due to the periodic nature of the pump: each droplet forced out of the tube is almost identical to the preceding droplet".

You need regular drops to get a good stop motion or reverse motion. That is basic physics/vision/film.

A strobe on a bog-standard watering can would be neato. A thing that looked like a bog-standard watering can could be made to emit regular drops by any reasonably competent lab.

But a strobe on a standard watering can will not make for stop motion. [ ]
-- baconbrain, Jul 05 2010


//A watering can has no emission control, it is just random.//

It's not fully random - the rate of droplet formation will have some short-lived regularities in it, so that there are fleeting moments when this train of droplets appears to be in slow-motion, to freeze, or to travel backwards.

I've worked on much smaller droplet generators and, by bizarre coincidence, did my old A-level project on droplet breakup in falling water jets. There are regularities, though they are very susceptible to disturbance, and they can be effectively strobulated.
-- MaxwellBuchanan, Jul 05 2010


What's the flashing? I'm strobulating! I just learned a fab new word. Thanks Max.
-- xenzag, Jul 05 2010


// regularities, though they are very susceptible to disturbance //

Disturbances such as filling the watering can with swirling water, lurching it out to the garden all a-slosh, tilting it carelessly and waving it back and forth over the flora quite carefully? Disturbances such as each hole being surrounded by other holes dripping at a slightly different rate? Disturbances such as kicking the stuffing out of the can when the droplets don't strobe?

The drips out of any one hole in a watering-can nozzle are not going to be regular enough to stop-strobe for any appreciable amount of time, anywhere outside of a Cambridge lab. (Interesting experiences that you've had, [MaxB], I do envy and admire you.) Nor are the droplets out of the other holes going to be dripping out at the same frequency, so any strobe rate will only get a few streams of droplets at any time.

// you'd get the middle of the spray arc looking like it's suspended in the air. Back towards the nozzle of this middle point it would look like the drops were accelerating back into the sprinkler. Further towards the lawn, the drops would accelerate into the ground.//

No, regular-interval drops (such as a watering can does not put out) will simply look closer together up high and further apart further down. The time interval between drops is constant, the distance between them increases with the distance they fall.

What you *might* get is the drops from, say, the upper side of the nozzle coming out at a slower rate than the drops from the lower holes where there is more pressure, so some regular streams might look like they are going up while others are going down. For a few seconds. [ ]
-- baconbrain, Jul 05 2010


I'm prepared to stand corrected, as long as someone makes one of these and proves it thus.

Did I mention [+] ?
-- Custardguts, Jul 06 2010


//... anywhere outside of a Cambridge lab.// I'll bet it wouldn't be that difficult. Just requires a little ingenuity.

Here's a solution (and I don't think it's the only one) that I believe would work:

Put a shaker on the nozzle. This is going to look just like a cheap hair clipper head - runs off AC mains power so the electricity powers the coil, drives the nozzle back and forth.

There will be a number of perforations in the nozzle, and each will be set at an angle rather than pointing straight out of the nozzle. (You can let your mind run off with other arrangements later, but let's just stick with this for a moment.)

Start out imagining water entering a perforation angled to the right, at the same time the nozzle head is accelerating to the right. The head accelerates the nozzle and perf feed tube, and the water inside it (it's not a perfect linkage, but surface tension in front and feed pressure behind helps the water keep up).

Then the head hits the stop, and starts to accelerate back to the left. Now the inertia of the water is pushing the water out of the tube, leaving an elongated droplet flying out of the nozzle.

Hit the stop, go the other way. Cuts off the flow, gets the next droplet ready.

Cut the cord, make the necessary changes to run off battery. Now you're out of both Cambridge and the lab...
-- lurch, Jul 06 2010


//The drips out of any one hole in a watering-can nozzle are not going to be regular enough to stop-strobe for any appreciable amount of time, anywhere outside of a Cambridge lab. (Interesting experiences that you've had, [MaxB], I do envy and admire you.) Nor are the droplets out of the other holes going to be dripping out at the same frequency, so any strobe rate will only get a few streams of droplets at any time.//

Baconbrain, you are absolutely correct BUT you will still get intriguing moments of strobing. Over a period of maybe a half a second or maybe several seconds (if you hold the can fairly still), the droplets from any one sprinkler hole will form at a fairly steady rate. It's not *perfectly* steady even in the short term, because droplet break-up requires an activation energy which comes from noise, hand-tremors etc. BUT the activation energy only modulates the inherent frequency of droplet formation.

So, briefly: you'll get tantalizing instants of strobe effects, lasting for seconds or less, from random streams.

HANG ON JUST A SECOND though!!!111!! I've got a strobe light and a watering can, and I will be setting the sun in a couple of hours, so we can.....Do the Experiment!!1
-- MaxwellBuchanan, Jul 06 2010


//I will be setting the sun in a couple of hours// [Max], if you'd like, you have our permission to put it down a little earlier than yesterday
-- lurch, Jul 06 2010


I would, but Mrs. Max likes to garden in the evenings.

(p.s. - I would hate you to think I'm getting megalomaniac or omnipotent or anything - I only do the sun over the Buchanan estate.)
-- MaxwellBuchanan, Jul 06 2010


[xenzag] very nice indeed!
-- dentworth, Jul 06 2010


I am back and slightly damp.

Sadly, one of the undergardners seems to have mislaid the rose on the watering can, so that experiment was a non- starter.

However, I tried it with the lawn sprinkler, and you have absolutely got to see this to believe it. I used a medium- power xenon strobe.

At low strobe-rates (on the order of 0.5Hz), you get an incredible freeze-frame effect, and what you see is a succession of still images. The images last (on the retina, so to speak) long enough for you to see gobs of water suspended in mid-air, or odd-shaped droplets and weird contorted sheets of water. It really is like looking at a rapid succession of flash photographs.

At higher strobe rates (up to about 20Hz - my strobe doesn't strobulate faster than that), you get a sort of flickery-movie effect. There are moments when the droplet train is regular enough and in synch enough to give "frozen motion" or "slow motion" effects, but only sporadically (the sprinkler rotates, and this probably affects the droplet rate as it turns).

And it is seriously beautiful, especially with the slow strobe rate. Somebody should market a lawn sprinkler with a built-in strobe. I think there's a flash rate below which (and above which) it's not likely to induce epilepsy.

Water, electricity, flashing lights....what more could a man want??
-- MaxwellBuchanan, Jul 06 2010


Thanks for the report, [MaxB], and once again I envy you.

The results are much what I imagined, and have been trying to describe.

I just had my first job interview in many years, and have been prepping for it for the past few days--not well enough, but I survived.
-- baconbrain, Jul 07 2010


Congrats, Bacon! And fingers crossed for the job...
-- MaxwellBuchanan, Jul 07 2010


Brilliant stuff [Max] - and congratulations [Bacon] - how much is a Xenon strobe now? I want to try this too.
-- hippo, Jul 07 2010


Just strobulous.
-- wagster, Jul 07 2010


Xenon strobes are cheap. I actually bought mine as a kit (one of those "junior electronics" kits - probably less than $20) from Maplin.

(I think you'd need a xenon, rather than an LED or regular light - the pulses need to be very bright and very short).
-- MaxwellBuchanan, Jul 07 2010


Maybe I'll build one myself after all. Thanks all.
-- xenzag, Jul 07 2010


I don't think there's any need to have anything fancier than an on switch and the strobe set to a single frequency illuminating the water through a hole in the side of the can. Or have the whole thing inside and properly waterproofed. You'd try to get that suspended drop of water by adjusting the flow. The droplets would appear move towards and away from the can until you got it just right.

Call it the "MagiCan" (Like magician only it's a can with magic) Have the user in the commercial look at the camera wide eyed and say "It's un- canny!" I'd fill the tv add with lots of can puns.

If you don't want to hassle with building it you could sell it as a kit. Just get the can, the strobe kit, a custom piece or two to hold it in place and throw it in a box with instructions. If you did this right you could send out your provisional patent for a hundred bucks and have this thing on the web in a week or two.

I'll buy the first one although I think I'd be waiting in line with the other guys here.
-- doctorremulac3, Jul 07 2010


See [link] for some kits. I think Velleman has some, also.
-- csea, Jul 07 2010



random, halfbakery