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The Time Fountain

All > Tech > Inventions > The Time Fountain by natetrue
Time fountains are now for sale! You can buy a fully assembled fountain ($200), a kit ($100), or the chip alone ($30). The pre-sale is over, sorry if you missed it! Interested? Buy now! ... You can also buy the parts yourself and check out the Assembly Manual.


I suppose it might be called a "Backwards in Time Fountain" or a "Time Manipulation Fountain" but I figured those titles would be a bit long.

Let's start with a video, shall we?

It all started when my friend Jesse told me that if you get a strobe light fast enough, you can make it look like dripping water is going in slow motion or even backwards. This phenomenon happens because strobe lights can 'capture' an instant in time and allow your eyes to see it as lasting longer than an instant.

So if the strobe light captures consecutive instants of time just out of sync with a periodic occurrence such as dripping water from a faucet, it can appear that the drops are moving slowly or even backwards.

Of course, since we had no strobe light of sufficient speed, Jesse and I never really pursued the concept.

A few months later, some casual surfing brought me to the artwork of Shigeko Hirakawa, who does some modern-art style installations over in France. I noticed something familiar about the water he uses:
I had seen that color of water before, on the TV show Smallville. I was intrigued, and after much googling (for "fluorescent dye") I found out that the dye was called Fluorescein.

I then knew the name of the dye. So what now? I head over to my good friend eBay, searched for fluorescein and bought a bottle of fluorescein reagent (powder) for about $15.

Unfortunately eBay seems to think selling Fluorescein is against their TOS and you can't find the powder there any more. But the company on the bottle ( ) still sells it.
The powder is a deep orange-red color and a pinch of it will turn an entire bathtub of water a very fluorescent, very acid yellow color, much to the chagrin of whoever cleans your bathtub. This stuff stains clothes and skin very readily, so be careful with it.
Did I mention Fluorescein is fluorescent? It glows a very satisfying bright green under blacklight.

You can see the idea forming, right?
Enter the idea. I wanted to make a fountain with strobing UV LED's which are expertly timed to apparently freeze a stream of fluorescent drops in mid-air.

Parts list:
- One small fountain and pump. Preferably battery-powered so we can power the pump with simple electronics. Try eBay for "battery fountain".
- About 32 UV LEDs. Available cheap on eBay (search for "UV LEDs")
- A short length of brass tubing
- Brass rods to solder the LEDs to
- Two NPN power transistors (TIP31 is what I used)
- A PIC16F628 suitably programmed
- One op-amp (LM741 or LM328 will do)
- Some other components (resistors, capacitors)
Using an old battery-powered small fountain as a base, drops are pumped through a brass tube, falling out of the end at a very regular interval. A microcontroller coordinates the speed of the pump and the strobe rate of the LEDs.
Start with the UV emitters. Solder all of the cathodes to the brass rod, and creatively cross-hatch the anodes behind so they're all connected.
These things can get very bright. Unfortunately since we're strobing them they will never blind you.
Next, jimmyrig the pump to work with your expertly bent brass tube. Pro tip: fill the tube with salt before you try to bend it. That way it won't collapse on itself.
Next, find some way to run a wire up the tube (be creative) and terminate just out the end with a gold-plated connector. Any other metal will corrode terribly. Use a short bit of aquarium hose to expand the drop size if you need to.
Now comes the hard part. Build the electronics according to the pretentiously artful/distorted schematic.

The left part is a simple drip detector circuit. As drops touch the gold contact and fall off of it, the resistance between the contact and the water will change. Combined with the 220 kilohm resistor, a voltage shows up on the + input of the op-amp which varies according to the drop's contact area. The op-amp is configured as a simple voltage follower to reduce noise.

The PIC has an internal comparator to compare the high-frequency component of the signal (the drops falling) to the low-frequency (the DC offset from the voltage divider). The result:
The sine wave is the incoming drop signal, and the lines represent the outgoing square wave that tells the PIC when there's a drop leaving.

That brings us to the center of the schematic. The hardware side of the PIC is very simple - just inputs to the comparator, a few buttons, and outputs to the LED strobes and motor.

The PIC uses a simple algorithm that could probably be implemented in hardware instead - the buttons increase and decrease the speed of the motor (via the duty cycle of its PWM output pulses), and the drop pulse will reset the strobe phase. The strobes are at a fixed frequency, so they'll strobe about five times per drop.
Fill the fountain with some urin.. I mean, fluorescent water prepared from the Fluorescein powder. Turn it on and cross your fingers!
The result? This is a four-second exposure. Those drops are frozen in mid-air.
One of the most fascinating things to do with the Time Fountain is to stick things in the path of the drops. The drops split and vibrate beautifully and you can move the object up and down to change the effect in the drop stream. Did I mention this phenomenon is phenomenally hard to take pictures of?
I sat there for maybe two hours playing with it. It's really something you do need to see in person - so fascinating and beautiful.
Another great thing to do is to play with the sync until the drops are moving in slow motion - and watch the drop splash in super-slow motion against the surface of the water.

If you want to get in touch with me, send an email to timefountain (at) natetrue (dot) com.

Also, be sure to check out my other creations.

More creations by natetrue

More creations in Inventions


Posted by jesse 7 years ago ( 07-Aug-2006 11:14:31 )

Amazing directions, even the less ambitious patrons of Make who never make any of the stuff they put on the website but still go there to oggle and dream could make this. Why? Because you don't leave anything to the imagination, which unfortunatly a lot of people lack. I think...even I could make this with these directions, your awesome Nate!

Posted by doppelfrog 7 years ago ( 08-Aug-2006 04:31:42 )

Fantastic. I want to build one, but then I read about the stains caused by Fluorescein.
According to my g/f my life's not worth that much... Instead I shall watch the video again. :-)

Posted by thesavant 7 years ago ( 08-Aug-2006 07:55:32 )

I wonder what would happen if you used fluorescein in one of the water fogger mist things.

Posted by natetrue 7 years ago ( 08-Aug-2006 09:16:43 )

thesavant, that's one of the first things Jesse and I tried. Unfortunately you need a super-high concentration of fluorescein to get the mist to glow at all, and even then it's somewhat unimpressive. Stains like hell too.

Posted by jschwabbs 7 years ago ( 08-Aug-2006 09:49:42 )

Kinda off topic here, but what is the name of the song you used in the video? It's pretty cool as well as the invention.

Posted by natetrue 7 years ago ( 08-Aug-2006 10:03:48 )

Rimsky-Korsakov, Scheherazade Movement II, The Kalendar Prince.

Posted by riney 7 years ago ( 08-Aug-2006 10:42:54 )

I have to build one of these.

I wonder if tonic water would make an acceptable glowing liquid? The quinine in it is supposed to fluoresce nicely under UV.

Posted by natetrue 7 years ago ( 08-Aug-2006 11:10:20 )

You can also buy a highlighter, open the bottom of it, and squeeze out its delicious highlighter-juice. I'm pretty sure that's fluorescein.

Posted by ozzman 7 years ago ( 08-Aug-2006 15:59:31 )

Im dying to do this can you please give a litt more detail on this

- A PIC16F628 suitably programmed
- One op-amp (LM741 or LM328 will do)
- Some other components (resistors, capacitors)

ive never tried a project like this but am excelent with soldering and wiring. also where did you get the gold connecter to cause the drip at the end of the tube? off what old product?


Posted by superfreq 7 years ago ( 08-Aug-2006 16:59:34 )

Awesome project! It might look cool with regular white LED's and regular water. Not nearly as glowtastic but could be cool. Maybe even colored water.

Posted by natetrue 7 years ago ( 08-Aug-2006 17:13:00 )

Thanks, superfreq. The reason I didn't choose white LEDs and water was that water doesn't reflect light, it just lets it pass straight through. With UV and fluorescein, the liquid itself is fluorescing and actually emitting light, giving very good visibility. With white light you'd have the reflected drops being several orders of magnitude dimmer than the lights themselves.

Posted by vayhey 7 years ago ( 08-Aug-2006 17:31:07 )

Honestly I love it. I want to start building one right away, give it a nice body and dress it up a little. My only question is where can i get a 'PIC16F628 suitably programmed' or just the chip and then tell me how to program it myself. I'm just in awe! I have to do this!

Posted by matt 7 years ago ( 08-Aug-2006 17:37:37 )

This looks amazing. I can't wait to begin building one, but as others have commented before I'm bit cautious about the PIC programming. If you could supply a bit more information about what needs to be done to have your PIC "suitably programmed" or even supply the code that you loaded. And a bit more detailed schematic would be great.

Thanks and awesome project,

P.S. Would this make a suitable PIC programmer for this project?

This comment was edited at 2006-08-08 17:39:41

Posted by natetrue 7 years ago ( 08-Aug-2006 19:29:45 )

Hi everyone, the reason I haven't released the PIC code yet is because it is more or less in shambles - at the moment it can only freeze time and I had to kind of trick it into going forwards and backwards. I'm working on a new firmware right now that will be full-featured.

Matt, this is the closest kit to the one I have for PIC programmers:
It uses USB so it's fast and easy to hook up.

This is the fountain I used as a base:
The same eBay search for battery fountain or cordless fountain should yield one or two.

Posted by damienknight 7 years ago ( 08-Aug-2006 19:30:29 )

PIC tutorial -

Posted by matt 7 years ago ( 08-Aug-2006 21:45:07 )

Thanks for the update natetrue. I'm gonna start gathering the parts now. As a follow up to my question about the ghetto-PIC programmer (here: That is based on this design (, which claims to be compatable with the 16F628 and many other. So, I will let everyone know how this works out after I do try it.

This comment was edited at 2006-08-08 22:01:52

Posted by qenton 7 years ago ( 08-Aug-2006 22:52:11 )

Fantastic project and a very well done video too boot. Will probably try it, however I can't make out your capacitors and resistor values. I can guess some, but Op Amp wiring is not in my very limited electronic knowledge. The PIC programming part, I can handle.

Posted by tim 7 years ago ( 09-Aug-2006 02:43:05 )

Very nice, I am certainly going to make this when the code has been put online.

Posted by tim 7 years ago ( 09-Aug-2006 04:59:41 )

A couple of questions: Can you post a movie of the fountain in its whole? And approximately how much drops are coming out of the tube per second?

This comment was edited at 2006-08-09 05:37:30

Posted by xsavior 7 years ago ( 09-Aug-2006 13:26:52 )

Out of curiosity, if i wanted to make the simple man's version, couldn't you just create a variable strobe control through a rheostat, and a coordinate that with the pump flow speed to get the same effect with out needing the PIC? of course that leads to the question of what could i use as a variable speed controller for the stobe on the LEDs...

Posted by adambard 7 years ago ( 09-Aug-2006 15:25:15 )

Along the lines of the guy above, could you dispense with the PIC by just using a 555 timer?

Posted by natetrue 7 years ago ( 09-Aug-2006 15:30:57 )

For basic functionality a 555 (or a pair of 555s) could work instead of a PIC. Use one 555 to control the duty cycle of the motor and the other to pulse the UV lights - you'd probably still want an op-amp to detect the drop and short out the strobe 555's capacitor (either to high or low, not sure which) when a drop falls.

It'd take some development but not much more than I have ahead of me to get the PIC firmware in order.

Posted by slackerboy 7 years ago ( 09-Aug-2006 15:49:53 )

I think you could get away from actually having to program LED strobe sequence to the lights if you could get finer control of the water-flow. Have the lights strobe at a fixed rate, then vary the frequency of the drops. Should be easy to vary the motion of the standing drop by moving it into and out of phase whith the strobes.

Posted by natetrue 7 years ago ( 09-Aug-2006 15:54:59 )

Yeah, that would work if the pump had good consistency. The fountain I bought was all old and crusty so the pump tended to jitter about causing some inconsistent drop frequencies. This inadvantageous phenomenon can be ameliorated if the pump pumps water into an upper reservoir instead of directly to the drop nozzle.

Posted by leomarth 7 years ago ( 09-Aug-2006 19:39:56 )

As a electronics student... fascinating. What Hz did you have the LED's set to, and did you use a function generator, or did you use your opamp like an oscillator?

Posted by avocade 7 years ago ( 10-Aug-2006 05:02:03 )

Great stuff. Thanks for sharing!

Posted by alain 7 years ago ( 10-Aug-2006 08:51:59 )

I wanted to post a few days ago. Some of my comments have already been said by others. Still I want to repeat that this is a fantastic project!

Also, as some people have inquired, it is in fact possible to achieve the same functionality with just a 555 timer. In fact it is possible to do so without the synchronization part of the device. Let me explain:

Nate's rationale for freezing time is absolutely on the spot. If you synch a flash of light with the water drops, each water drop will have fallen exactly the same distance each time the light flashes. This will give us the illusion of time being frozen. But what if you want to move in slow motion forwards or backwards? Well you will need to adjust the timing of the flashes such that each consecutive flash is is triggered in a longer and longer time (or shorter and shorter) so that each consecutive drop has the chance to fall a little more (or a little less).

This can be done in software via a PIC microcontroller.

But there is a shortcut.

The synching of the flashes of light and the drops of water is not crucial for this experiment. All you need to do is have the dripping rate be a multiple of the flash rate. If this condition is met, you will have frozen time. Additionally, if the timing rate is slightly out of phase with the dripping rate, then you get a slowmotion or a motion backward effect.

So in essence you can do all this without both a synch circuit (op amp comparator) or a PIC microcontroller. A simple 555 will do the job if you reverse the output to drive the LEDS so that you can have a short enough pulse width and an adjustable frequency that are independent of each other (pulse width and freq. are different things).

If anyone is interested I could post on my site a more detailed explanation on how to build this version of the Time Delay Fountain.

Thank you Nate for bringing this to us!

Posted by vayhey 7 years ago ( 10-Aug-2006 10:55:15 )

Alain - I'm absolutely interested in your method for a simpler controller. I wouldn't say I'm a pro at electrical components, but i can work my way around them. Also, about the electrical schematic, is there anyone that can clarify it for the rest of us? It's a little tough to read. PDF of a vector or Visio doc?

Posted by shalmanese 7 years ago ( 10-Aug-2006 11:30:36 )

There is exactly this fountain except with two streams of water at the MIT Museum in Boston.

Posted by keen 7 years ago ( 10-Aug-2006 20:10:36 )

would you not get the same effect with just one UV strobe light with a speed controller?

like speed up the strobe and slow it down to get the same effect?

i remember in high school my teacher doing a similiar thing with a spinning piece of string. where the strobe would be syncronized with string to catch it at a certain position while its spinning.

Posted by manse 7 years ago ( 11-Aug-2006 07:38:34 )


You could do that, if you had a UV strobe light. In essence, that's what he has done. The PIC microcontroller is just a speed control (and bonus synchronizer) for the LEDs. My guess is the LEDs will give a better effect than an old fashioned strobe light, simply because they are more easily controlled

Posted by bones 7 years ago ( 12-Aug-2006 02:31:05 )

I don't think some of you guys are going to get what you want by contolling the motor speed.
If the strobe is constant and you control the motor. all you will see is more drops. Gravity is still the same.
I'm looking at the 555 timer idea to build a basic one and a Pic or AVR for a more advanced one.
Having many patterns. eg bouncing drops, the clasic knight rider effect etc.
I've worked out it will take 0.2424 seconds for a drop to travel 300mm so all is needed is to time from 0 to 0.2424 seconds max. Then you can vary the position of the drop. Don't forget it Accelerates so it will be quicker near the bottom.
Cheers for the idea. Brilliant.

Posted by crujones 7 years ago ( 12-Aug-2006 07:31:20 )

I would be very interested if someone could post a 555 timer schematic

Posted by rodent 7 years ago ( 12-Aug-2006 14:12:52 )

Alain: if you are interested in posting more details on your website, I would love to see them.
Bones: killer ideas, I don't have the knowledge to build a PIC to do it, but I like the idea.
I think there are some really good ideas in here, so thanks to natetrue for starting up the think tank. This link led me to discover
To the EET gurus hard would it be to input a signal (ie an sound level input) that would speed the sync up and down? Then as music got faster the drops would appear to speed up, then pass through stationary and into low reverse as the music slowed?

Posted by keen 7 years ago ( 12-Aug-2006 19:00:48 )

so lets say you get the fountain, get the liquid, then get something like this: (for some reason this link isn't coming all the way so don't click on it, copy and paste it. sorry)

then change the led's that are in there to the UV LED's, and put it together, do you think that would do the same? because you can control the speed of the strobe, and i assume that all you need to do is to fiddle with the speed till you get it to produce the same effect. right?

This comment was edited at 2006-08-12 19:02:53

Posted by bones 7 years ago ( 12-Aug-2006 23:18:06 )

I'll look at the 555 idea duing the week. Hopefully my UV LED's will be here soon. I'll post as soome as it's done.
Rodent: I was thinking of that idea too. Sound would be a good input and there's heaps of circuits out there. I'll have a look.
Keen: That unit would work but there would have to be some changes.
It will have to be timed from the drops. And then adjusted by the sound.
I was thinking of having sound out. Playing "Popcorn" as the drop it jumping around to the music. And have multiple drops. Like and equaliser. LED's shining upward for each stream of drops.
But thats later.
Thanks again Nate

Posted by stickyc 7 years ago ( 13-Aug-2006 22:42:08 )

Just thinking out loud here - what about regular water and a penlight laser module pointing upwards through the stream with regular water? You wouldn't have quite the fun with blocking the water (the beam would block), but it would make for a different effect.

Posted by elder 7 years ago ( 13-Aug-2006 23:25:44 )

I'm gonna make a PIC based one, one with more I/O though for individual LED controlling reasons. My UV LEDs are on the way now. Might be a bit of a hassle to get the UV reactive stuff to Australia so I'll try some easy alternatives that are UV reactive first, not sure if they are anywhere near as effective, time will tell.

I'm going to stick with the side on LEDs. I'm going to individually control each LED (or group sets of a few LEDs atleast) because after the basic setup I plan on making the UV light more directive and only lighting up certain LEDs so I can single out particular 'drops' and track them with the particular UV LEDs as the height varies. Then I'll do the bouncing drop effects etc with only showing a single drop.

Posted by bones 7 years ago ( 14-Aug-2006 07:20:40 )

Holy crapping duck poo. These are going for $350 USD on Ebay.
Nate Great job. Are you still alive I see no post from you.
Stickyc: Worth a try using a laser.
Elder: I'm Aussy land too.(Perth) You can get a green powder from joke stores that glows in the dark but I'm not sure how it will go with UV. But what about car engine coolant. It's floro green but needs to be tested with UV.. Good luck with the multiple led idea. You could just have a continuous stream instead of drops and turn on the area you want.

Posted by alain 7 years ago ( 14-Aug-2006 12:10:56 )

Ok I got a page up explaining how to make the simpler 555 timer version. It works fantastic (both with UV or white LEDs).

I am still tweaking the component values to get the optimal configuration. But it also depends on your water drop source. If it is too slow, the strobe is annoying and if it is too fast, the adjustment pot gets more difficult to set.

(Remember that you not only need to control the frequency of the strobe but also the width of the pulse so that it is short enough.)

This comment was edited at 2006-08-14 12:13:04

Posted by natetrue 7 years ago ( 14-Aug-2006 13:33:00 )

Hey guys, if you're hurting trying to find Fluorescein just buy a pack of highlighters. If they glow in UV you're golden - yellow highlighter is (I think) fluorescein-based ink.

Alain, thanks for that beautiful write-up. It explains the concept far better than I ever could.

Oh, and I should also mention that I'm going to make a very thorough howto on the Time Fountain version 2. I expect to release the plans on

A company is also considering manufacturing the Fountains too. Still waiting for approval on that though.

This comment was edited at 2006-08-14 13:34:48

Posted by anavrintobin 7 years ago ( 15-Aug-2006 11:50:47 )

Wow! Fantastic creation. Good luck with getting a company to manufacture them ($351 on ebay last count, they would be mad not too!) I look foward to the full guide and the fun to be had trying to build it.

Posted by dasaint 7 years ago ( 15-Aug-2006 20:23:09 )

Schematic for the Time Fountain.

This comment was edited at 2006-08-16 04:35:24

Posted by jorsher 7 years ago ( 15-Aug-2006 22:25:41 )

Hmm...looks like my willem chip burner will be good for more than programming my ecu :)

Any good tutorials for reading those schematics or anyone else have video's of theirs? Been reading up for more information.

Posted by natetrue 7 years ago ( 18-Aug-2006 11:23:17 )

Hey again guys,

Ends up highlighters work better than powdered fluorescein. Just buy a (jumbo) highlighter, chew the end off of it, remove the inky sponge, and squeeze it into your water. Powdered fluorescein tends to precipitate out of the water, leaving a lot of red-orange crust at the bottom of your tank - highlighter ink for some reason does not do this.

Posted by dasaint 7 years ago ( 19-Aug-2006 00:52:30 )

can you do reverse with 555 chip?

Posted by alain 7 years ago ( 19-Aug-2006 13:21:51 )

I have been using a green fluorescent dye from another project and it works great. I also added some white paint to it to make it reflect more light.

Yes, you can do reverse with the 555 chip. In fact it's so much simpler. Check my website for explanation (URL above).

Posted by emzed 7 years ago ( 22-Aug-2006 03:02:37 )

Awesome idea! I've already ordered my LEDs. I think i'll go the microprocessor option but i'm more familiar with AVRs so it'll probably use one of those. Have you experimented with height? I would love to capture a 'crown' splash but i think the drop would need a fair bit more velocity.
BTW, if anyone from Australia is interested, i've bought 100 UV LEDs off ebay and i'm willing to split a pack.
email me: ziebarth at internode dot on dot net

This comment was edited at 2006-08-22 06:27:20

Posted by bones 7 years ago ( 22-Aug-2006 06:52:45 )

I ended up ordering a 300mm strip of UV leds from

12 Flexible LED Strip
I don't think they are as bright as the individual LED's But I'll give them a go.

Note Do not trust these people. Complete liars. You might get your goods but it will take a month.
Bought parts on the 10 Aug......spoke to them on the 27th Aug.... "uuhh yes we ship on the 13th Aug must be in customs" (Big fat lie)..... afew emails with no replys until on the 7th Sept...Threaten them with going to ebay.......7 Sept....We very sorry, order was delay. and give me a tracking No.
Looks like you have to pay the express shipping for them to think about shipping.
Don't trust them. Sorry if anyone has used this link to buy LEDs;

This comment was edited at 2006-09-07 05:29:52

Posted by emzed 7 years ago ( 22-Aug-2006 17:05:04 )

Hi Bob,

I've added my email to my previous post if your still interested in the UV LEDs.

Posted by jcb 7 years ago ( 25-Aug-2006 14:11:05 )

Woo Nice

This comment was edited at 2006-09-04 08:48:21

Posted by chumbaz 7 years ago ( 29-Aug-2006 12:02:54 )

Any chance you could post the pic code, like your other projects on

Posted by striver 7 years ago ( 30-Aug-2006 13:46:42 )


This comment was edited at 2006-10-08 02:14:10

Posted by booster 7 years ago ( 05-Sep-2006 03:46:29 )

great creation
what frequency of the strobe did you use?, because when i try it it doesnt look that well

Posted by bones 7 years ago ( 07-Sep-2006 05:32:35 )

I have edited my message above about a ebay link for cheap LED's. DON'T USE them.
Unless you want to wait a month for them.
Sorry if anyone has used that link.

Posted by farrier 7 years ago ( 10-Sep-2006 11:29:49 )

Argh! Don't you get it? None of you get it!

This isn't just a time fountain. Well, OK, this implementation of it is: with a little code and a drop falling four times a second, you can have the drop appear to rise and fall smoothly at an average 4hz (more when it rises, less when it falls).

But the concept is bigger than that.

A row of X fountains, with the flashes arranged so that each flash can only hit one fountain, and you have a graphic equaliser X bars wide.

But the concept is bigger than THAT.

But what if you have, instead of one flash per drip, two flashes? Then you appear to have two drips. In fact, you could have up to Y virtual drips, where Y is the fall distance divided by (average drip size+fall distance in one flashtime).

So the concept is... a 4Hz, X-by-Y pixel raster display!

You can have a regular-looking fountain in your room, but when you dim the lights, glowing droplets start slowly rising in reverse out of the water until your love's name is there, suspended and glowing a flickering green in the darkness... Then the word morphs into "death"! Excellent way to get rid of an unwanted lover! (OK, might also work for declarations of love I guess).

If you had programmed control of the drip speed (stepper motor on a valve? You don't want each fountain to need a separate pump, so have them all fed from a reservoir), then you could actually make the refresh rate better than 4hz in some cases: the next drip could be lighting the topmost pixel as the first one lights the bottom one, in some cases.

Posted by farrier 7 years ago ( 10-Sep-2006 11:45:01 )

In fact, with programmed drop control, you could just print out the whole raster at once, compensating for the approx exponentially increasing speed as it falls, then have one global flash to make the water glow. Still avg 4Hz, and less hassle with keeping the column flashes separated (since near-UV lasers are v expensive I think).

Frame-rate increase optimisation would be possible where the bottom part of one frame was equal to the top part of a preceding frame, eg, when spelling out:
If that took up the whole display height, then you'd get that at better than 5Hz. "DODO" would be 8Hz. AAAA would be 16Hz. But these optimisations would cause inconsistent brightness and flicker, so might not be desired.

Posted by kleptophobiac 7 years ago ( 11-Sep-2006 20:32:51 )

This project is fascinating and I'm looking at turning it into a dorm toy. I just started and am getting the easy stuff out of the way first:

I've always been a sucker for PCB. Next up is strobing them with an existing microcontroller I built some time ago. After that comes drop detection, and finally software integration.

Posted by happycrappy 7 years ago ( 11-Sep-2006 21:13:29 )

Awesome project, it just hit the top of my todo list...I've been reviewing your instructions and am still a bit confused about the drip detector of the connections is the wire going through the tube, whats the other one? or is it 2 wires that are in the tube?

thanks for the inspiration,

Posted by striver 7 years ago ( 12-Sep-2006 11:24:46 )

Any books you can recommend to me (ppl above)?

Posted by noonevac 7 years ago ( 12-Sep-2006 19:12:18 )

We want the PIC CODE...... COME ON BUDDY, you have posted everything to one of the most amazing projects ever!! except the vital PIC CODE.... :) help us out!!!!

Posted by noonevac 7 years ago ( 12-Sep-2006 19:14:35 )

ok its been like 30sec and no word on the PIC CODE...
Dont you ever check out your site :) done..........ill waiting..........

This comment was edited at 2006-09-12 19:15:18

Posted by puddyman 7 years ago ( 13-Sep-2006 13:21:08 )

I can't thank you enough for inspiring me with this wonderful idea natetrue, its kept me occupied for weeks.
My version of the (almost) finished fountain here:

hope you guys like it!
any questions about building one of these beauties, feel free to email: i'll try to help out.
(I went with the 555 timer option so don't ask me about PIC code)

Posted by kleptophobiac 7 years ago ( 13-Sep-2006 17:27:47 )

Puddyman - I really love the creative aspect of your design. It's hilarious!

I just started writing the code for mine today, I'm using an Atmel 89S51. It's a fairly quick 8051 clone that lacks a lot of the whizbangs of some of the new models. They're easier for me to deal with than PIC systems so I'm using it. The firmware is almost done, though not yet tested. When it's good I'll post it. It's in C.

Posted by kleptophobiac 7 years ago ( 15-Sep-2006 17:45:42 )

Well, I have to put the project on hold until winter break. Too bad.

I was having some problems getting drips rather than a continuous stream, as well as with noise affecting the drip sensor. I think I'm going to go for a two-leaded approach rather than using the copper plumbing as a lead and then use the prongs to facilitate drop formation by having them diverge like an upside down electrical jacob's ladder.

Nate... some questions on implementation:

For motor PWM are you using timer generated interrupts and a counter to turn power to the motor on and off at regular intervals? What's the base frequency and your adjustment resolution?

What do you do about noise on the drip sensor line? Being a long wire in proximity to power supply, fluorescent lights (since I work inside), and near a PWMing computer... it gets signal from other than just the drip. I think using a narrow gauge coax might be a better deal. Also, when the computer starts and before water is moving trough the pipe the comparator is looking at long and short term averages, so it does a fantastic job of squaring up 60Hz line noise.

It would be great to see your MCU code! Thanks!

Posted by mikewrox 7 years ago ( 24-Sep-2006 11:17:02 )

Hey, about to start building my own time fountain, but I don't quite understand how the drip sensor works, do you have a contact in the middle of the drip path, and the drop itself completes the circuit? (the current runs through the drop itself). Also, I've never worked with op-amps, what is it used for, and how do I use it?

This comment was edited at 2006-09-24 11:19:07

Posted by niksun 7 years ago ( 25-Sep-2006 15:40:06 )

Well, I'm just about ready to get started on my time fountain. I opted to go with controlling the speed of the LEDs as opposed to controlling the speed of the motor and detecting each drip. I figure I can rig up something to give me a constant drip rate and just adjust the LED blink rate to do the effects I want. I'm not interested in perfection, so this will probably be OK for me.

I modeled my basic circuit on the Stopping Time Visually idea at:
I just added another 1K pot in series with the 10K for fine adjustments. I'm still in need of the fluorescein, but I think I'll try the highlighter idea first and hope that it works.

I am building this thing for my yearly Halloween party, so I think I'll make the water drip out of a witch's nose (a mask) and into a witch's stew pot. I'll post pics as soon as it's done!

Thanks so much for the great idea natetrue! Also, thanks to puddyman for the additional inspiration!

This comment was edited at 2006-09-25 15:43:51

Posted by niksun 7 years ago ( 13-Oct-2006 18:49:45 )

OK, so I've built my time stopping fountain. Well, at least I'm about 90% of the way there. All that's left to do is to solder the UV LEDs as opposed to having them on breadboards (but I wanted to make sure of the height/width first), adding a left hand on my witch, painting the PVC frame black, and getting the fluorescein. For a test, I used only one highlighter pen and shook it in the water and it worked pretty damn well, although it doesn't look so good in the image (see below). I figure that 2 of these pens would last the entire halloween party!

Anyways, as I said before, I opted to build a witch and have the water drip out of her nose and into a witch's stew pot. I put all the circuitry into a neat little red box. I got a cheap pump (which is way too powerful for this app, but it was cheap) from Electronic Goldmine and hooked up a toilet ball valve to regulate the water coming out of her nose. I hooked up some red LEDs in some eyeball ping pong balls for effect. I'm wondering though if I should sort of hide the UV LEDs from being seen from the front since they can get distracting. Or maybe they can be eye catching too so that my guests can notice the witch in the corner of the dungeon... I dunno.

I opted to go with the Stopping Time Visually idea (slightly modified), which is plenty fine for me although sometimes the water goes a slight wee bit faster or slower for a moment which throws things off for a bit, but what the hell. Check out my altered schematic here:

Thanks to everyone for the help! If you have any comments, please shoot em my way: jean_gourd at hotmail dot com (please tell me you can figure that out)!

Images for your enjoyment:

This comment was edited at 2007-06-27 14:07:22

Posted by jesse 7 years ago ( 08-Nov-2006 06:57:59 )

This should probably be in the hall of fame!

Posted by natetrue 7 years ago ( 21-Nov-2006 14:26:28 )

What hall of fame?

Posted by kleptophobiac 7 years ago ( 22-Nov-2006 21:13:25 )

I'd still really like to see the PIC source code. Also, what toolchain did you use to compile? MPLAB and PICC? Something else?

Posted by zorbskie 7 years ago ( 25-Nov-2006 20:42:57 )

you could probably try here for some UV Products

This comment was edited at 2006-11-25 22:54:38

Posted by jetcowbob 7 years ago ( 05-Dec-2006 22:10:14 )

So i was curious, and i did a search and found this patent:

Talk about stepping it up a notch! I wouldnt be surprized if someone has done a more detailed RGB flourescence. Ive seen some different colored flourescence powders that are soluble in different liquids... including water, alcohol, acetone...

( US Patent # 4294406 ) frepatentsonline is a very nice interface. FREE Too!

Posted by dave 7 years ago ( 09-Dec-2006 04:35:00 )

there is a time fountain on ebay,
its only a 555 one tho but it looks pretty dam nice

This comment was edited at 2006-12-09 04:38:32

Posted by deception 7 years ago ( 13-Dec-2006 11:04:00 )

If anyone wants some good quality LEDs check out They have all kinds of leds, all quite cheap ($0.45 each and up) and only $2 min shipping anywhere in the world. Check them out, they are really great at shipping things out right away.

Posted by kleptophobiac 7 years ago ( 19-Dec-2006 14:03:02 )

I'll second ... they've treated me quite well.

I'm finally back home, and able to work again!

Posted by kleptophobiac 7 years ago ( 30-Dec-2006 20:39:50 )

And it works!!! I haven't gotten the software quite right for asynchronous (water falling up) mode yet, but droplets frozen in time mode works great!

I'm overjoyed! I had to modify the schematic a bit to make it more robust, but it does work. Hurrah!!!!!

Posted by sebwca 7 years ago ( 03-Jan-2007 05:38:09 )

Hello ! i am french, so excuse my poor english.
i would like to plan my own time foutain. Is anyone have a tutorial or a DIY guide ? my question are especially on the electronic parts. I have no skills on PCG or in PIC programing !


Thanks to all for your help !

Posted by mitch 7 years ago ( 06-Jan-2007 21:14:57 )

if i wanted to use try colour LEDs and change the colour would i get the desired affect or would a) the leds not be strong enough or b) the fluorescent die cannot change colour just with a coloured light?

It is an effect i would like, but i just wonder if it is possible.

Posted by jackass 7 years ago ( 14-Mar-2007 09:17:16 )

can some one please post a scamatic of the foutain but with a 555 timer
asap im macking this as a science project and ive got 7 days

Posted by kokopellithemuse 7 years ago ( 09-Apr-2007 09:49:17 ), comment hidden (show)

I was wondering how much money it costs to make?
And can i please have the PIC code!

This comment was edited at 2007-05-18 08:33:05

Posted by dillydog 7 years ago ( 20-Apr-2007 15:10:06 )

When are you going to make the PIC code available? or is it a basic stamp. I am just soooo longing to make one of these and it's only the PIC that's holding me up.

Posted by lakej 6 years ago ( 03-May-2007 06:19:09 )

Any updates on the availability of 3rd generation time fountains (through a toy company)? I'm still hurting to get one of these for my physics class -- it's perfect for my lesson on 'stopping time' (Edgerton photos and all).

Posted by natetrue 6 years ago ( 06-May-2007 14:48:22 )

Work on the 3G's commences tomorrow. I was working with a manufacturer but they flaked so I will be making kits available as well as assembled Time Fountains. Stay tuned for that.

Posted by natetrue 6 years ago ( 10-May-2007 13:34:41 )

Time fountains are now on pre-sale at a special discounted rate, which will expire as soon as the first fountain ships (should be early June). You can buy a fully assembled fountain ($175), a kit ($75), or the chip alone ($20). Once the pre-sale ends, the prices will go up to $200, $100, and $30 respectively. Interested? Buy now!

Posted by luka 6 years ago ( 12-May-2007 12:29:08 )

wow like it, finally on sale, sorry to hear the manufacturer pulled out. im a product model designer and rapid prototyper and have been workin on my own version for a while now, you can see it in youtube under my time fountain, lewis evans. id be interested in workin with you to figure out a design for ya if your interested give me an email, if not good luck with takin it further and cheers for the inspiration its a dam fine project, nice one.

This comment was edited at 2007-05-13 09:37:49

Posted by natetrue 6 years ago ( 13-May-2007 09:39:24 )

Lewis, that's beautiful! Excellent design and cinematography as well. I'd love to work with you - drop me an e-mail and we'll talk.

Posted by crujones 6 years ago ( 13-May-2007 18:23:10 )

Here is one of two time fountains I built for Christmas presents. I was just learning to tig weld stainless sheet metal.
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Posted by crujones 6 years ago ( 13-May-2007 18:24:12 )

next pic
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Posted by crujones 6 years ago ( 13-May-2007 18:24:48 )

next one
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Posted by crujones 6 years ago ( 13-May-2007 18:25:22 )

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Posted by crujones 6 years ago ( 13-May-2007 18:26:39 )

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Posted by crujones 6 years ago ( 13-May-2007 18:27:57 )

last picture
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Posted by luka 6 years ago ( 14-May-2007 11:53:25 )

hey nate , sent an email to your email hope that is ok couldnt find anyother :)

my email is

This comment was edited at 2007-05-15 15:45:04

Posted by kokopellithemuse 6 years ago ( 18-May-2007 08:44:41 )

I am working on a time fountain and i got my UV LEDs from this ebay store
you get 100 and only about $9. :-)

Posted by natetrue 6 years ago ( 24-May-2007 12:29:54 )

Development on the Time Fountains is proceeding excellently. Early June ship dates for the earliest orders seem like they'll be met pretty well.

For the record, I discovered that fluorescein glows brighter when illuminated with cyan-blue light than it does with UV, but the effect is not as striking because you can see the blue light also, making the fluorescence appear less bright in comparison.

Posted by awelucid 6 years ago ( 10-Jun-2007 12:04:10 )

Hello Nate True and fellow creators, I was inspired by this awesome poject to build my own artistic rendition with a friend and we are in the processes of doing so. We are attempting to build a series of 3-4 foot tall hanging bamboo temple fountains with the tubing and LED arrays hidden in the shafts of bamboo pointing inward at the drops coming down the center, rising and splashing off of various organic objects in their path before reaching a lit misted pool at their bases. We are doing this to set up an ambient garden area for the South East reginal Burning Man festival (Transformus) in July. But thus far we are having a few issues and would love some advise.

Our problem is this: The only drop that is actually dead in place is the one right at the sensors. the others are kind of in place but they skip around too much, almost in a predictable way. which leads us to believe that the code and device are working but the pump is shooting out at an irregullar pressure. any other ideas about what it could be? One solution would be to build a resevour at the top with a drain hole drilled to keep it at a certain hight- gravity is pretty constant last i checked. But we are using store bought dripper nossels from a hydroponics shop (which were our angels when we discovered their existance) but when we use a resevour our drippers are too slow, and unless we had a hugely tall resevour the water pressure isnt enough to create the desired effect. Crujones posted pictures of a what looked like a resevour based dripper, but our dripper making skills proved pretty lame which forced us to the hydroponic drippers. ****Is there a technique for making drips and not streams of water so that a small resevour can work? We havent yet tried the pulse Width modulation to the motor, perhaps this is a cure for more predictable, consistant water pressure? Did/would that also help with the creation of drips and not a stream?
Also what is the best method to offset the strobe (or motor speed) in the code- (for slowing down/reversing movement). We would like to do this with infra red or ultrasonic sensors, so that the drip rate changes to a halt as you approach and reach into the fountain.

Much thanks for the inspiration, and for any advise to be offered.
Awe Lucid

This comment was edited at 2007-06-10 12:15:13

Posted by luka 6 years ago ( 11-Jun-2007 16:57:13 )

hey. in my opinion when making these things the dripper is crutial for a good drip, any inconsistances scratches etc make for an iregular drip, meaning that the drip drips in a slightly different place every time, swinging in one dirrection or another as it trys to kling to the hoze edge as it leaves, this can seem to be in a patturn due to the fluid dynamic. so yeah getting a better dripper may be a good idea, if you cant make one try somthing from a scientific equipment store, there are some glass drippers out ther that can be goood enough. also this inconistencey could be because of the size of your fountain, this inconistency in the drip is multiplied the further the distance the drip falls, makeing it a bit smaller may give you better could also incorperate a tap at the top to give you some control of the water pressure.
also, imo using a pic code based fountain is flawed as you have a drip sensor in the path of the drip effecting its path same as above, try just haveing a resevour filled with a pump and an overflow to keep the water level/water pressure constant, as you said gravity is constant and this method will give you flawless drips, then just use a pulse width modulation to run the lights. it takes a little setting up but it definatly works.

Posted by luka 6 years ago ( 11-Jun-2007 16:58:00 )

ps give us some photos when its done, sounds like an interesting design :)

Posted by tim 6 years ago ( 18-Jun-2007 13:45:05 )

Nate, can you explain to me why the drops appear stuck in air when the LEDs strobe five times a drop? It's hard for me to understand that. I mean, when a drop falls and the LEDs strobe five times until the next drop falls, the first drop just can't appear to be in the same place each of those five times the LEDs strobe, right?
And also, what is a good height for the drops to fall from? 7 inches? 10 inches?

This comment was edited at 2007-06-18 13:46:52

Posted by natetrue 6 years ago ( 18-Jun-2007 22:33:57 )

Hi Tim,

The 5 strobes show the drop in 5 instants as it's falling - so instead of making a single drop freeze at once it appears a column of 5 drops is frozen.

I've found anything more than 7 inches makes too much splash, but you should be able to calibrate the flashes for any height.


Posted by tim 6 years ago ( 19-Jun-2007 13:03:50 )

Thanks, I misunderstood that part. This week I'll recieve my DC pump, so the building of my fountain will start then. Both pump and LEDs will probably be controlled by 555's, and not by a PIC. The only thing I'm worried about is that without a drip sensor I need to continously change the LEDs PWM to synchronize it with the drops, but maybe that's just a question of a continuous steam of drops exiting the tube.
What I still have to figure out is how long (in ms) the LEDs will be on every time they will flash, if the LEDs are on too long the drops won't appear to be standing still, and if they are on too short the LEDs won't appear to be constantly on. Right? So do you have any suggestions on that?

Posted by natetrue 6 years ago ( 19-Jun-2007 13:22:42 )

The strobe time is all about balance. Fortunately the drops aren't moving very quickly and you can get away with longer strobe times - You can also remove series resistors if you want bright strobes. They won't harm the LEDs if the strobe isn't continuous. Just make sure the 555 doesn't short out and leave the LEDs on. By my calculations the current incarnation of the Time Fountain pulses the LEDs for about 650 microseconds.

Posted by tim 6 years ago ( 20-Jun-2007 05:57:10 )

Don't you mean 650 milliseconds? 650 microseconds is 0.00065 second, seems very short.

Posted by natetrue 6 years ago ( 20-Jun-2007 07:49:41 )

Strobes are generally very short. 650 milliseconds is well over a half second, more than the time it takes for a drop to fall the complete distance.

Posted by tim 6 years ago ( 20-Jun-2007 10:04:14 )

How many cycles (LED on and off again) do you have in a second?

Posted by wasney 6 years ago ( 07-Aug-2007 01:33:35 )

I love this. I plan on buying either the completed or kit when I have some extra cash :D I am also sticking a link on my site and around a few other places...who knows, maybe I can get the cash to buy one by convincing others to get!

Posted by luka 6 years ago ( 21-Aug-2007 14:42:16 )

hey nate where did you get your dc water pump from? really need help finding a cheap dc water pump, that i can buy allot of

Posted by builderchad 6 years ago ( 19-Nov-2007 14:51:09 )

Hi, great little invention. I would like to buy a kit but am in the UK. Can anyone tell me if the $6.50 shipping would cover shipping to the UK. I doubt it so didn't want to put the payment through on paypal yet.


Posted by deckatina 6 years ago ( 02-Jan-2008 16:43:53 )

Aren't the uv-leds harmful to the eye?

Posted by andymuffins 6 years ago ( 17-Jan-2008 12:29:26 )

Nate, I sent you an email about this as well, are you still looking for manufactures for the fountain?

Posted by jordancalifornia 3 years ago ( 19-Jul-2010 20:50:06 )


thanks for the great work you all have been doing.

first of all, can anyone write arduino code for this, or does someone already have it? arduino is an open source micro-controller that is great. google it for more info. If someone wrote arduino code for this, you could have the ability to control the speed of the flashes, the brightness, and the durations. Also, if you wanted this to run all day for a decoration, you could do a loop and make the water trickle upwards slowly, and then downwards slowly like in this video.

Also, how do you make the water drop fast without turning into a stream? I found this very difficult. can you use a harbor freight small water pump? I couldn't find a good one on e-bay. What is the company that makes the pumps in the kit? does it say?

Posted by jordancalifornia 3 years ago ( 19-Jul-2010 20:51:31 )

no, uv leds are not bad for you.

Posted by kreditkontroller 3 years ago ( 20-Sep-2010 09:16:00 )

Time does not exist. Thats what Einstein was talking of. Anyway, lovely article, hit the jackpot with this one. Dennis

This comment was edited at 2010-11-14 10:22:49

Posted by bedrift 3 years ago ( 14-Nov-2010 02:39:20 )

Nice device of simple drip fountain that has been colored with UV reactive dye.

This comment was edited at 2010-11-14 10:22:09

Posted by chrisbond 3 years ago ( 04-Mar-2011 23:00:18 )

This comment was edited at 2011-03-04 23:03:03

Posted by davediamond 2 years ago ( 12-May-2011 07:00:37 )

Hi! I've also made my own version!
Here a video too:
Attached image:

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