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The Time FountainAll > Tech > Inventions > The Time Fountain by natetrue
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.
You can see the idea forming, right?
- 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)
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:
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.
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.
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