Introduction: DIY Time Fountain


Inventor: Dr Edgerton

Name of the invention: Water Piddler

Edgerton's Piddler, also known as a "Time Fountain", uses a stroboscopic light source to highlight individual drops of water at a specific frequency. Varying this frequency may freeze or slow or reverse the drop fall!

It's like freezing time or even reverting it... :-)

DIY tutorial links

Nate True DIY time fountain

Dave Diamond Mark 1Mark 2

Shawn Patton and his really nice powerpoint documentation

Step 1: What's New With This Tutorial?

- detailed shopping list

- detailed electronic board

- detailed assembly and design instructions


- no UV led (standard led + oil of milk like Shawn)

- lesser noise (peristaltic pump)

Step 2: Shopping List: Total Cost Below 15€

- waterproof LED strip 30cm 15 leds 0,9€

- Electronic components < 2€

- 1x NE555 0,04€

- 1x capacitor 100µF

- 1x 10Ohm resistor

- 1x 470Ohm resistor

- 1x 10K linear potentiometer 0,70€

- solderless breadboard or copper breadboard 0,4€

- 12V Peristaltic pump 19 ~ 100ml/min D4 10€

- 1M Clear Food Grade Flexible Hose Silicone Tubing OD 5mm/ID 3mm 1€10

- 12V power supply unit 2,77€


- OOM (Oil of Milk) 5€

(en français LAIT FACTICE) 5€ 5€ + 5€80 rupture 5€90

Step 3: Electronic Board: Stroboscope

Design from Alain Bellon: his site is closed but I saved it under pdf ;-)

The NE555 discharge at full speed (the shortest blink as possible) and the potentiometer allows to change frequency (from continuous to xx per sec)


Place the capacitor the closest to the NE555 (precision timer).

If you use a LED strip meant to be used on car for example, there is already a built-in resistor. In this case, it's no use to add the 220 Ohm resistor. If you wire LEDs, you have to calculate the resistor value accordingly:

There is plenty of online resistor calculators. This one is nice to use and deals with serial LEDs and write the results with a nice layout.

  1. you can use a solderless breadbord
  2. Or a copper board which require soldering. Don't forget to scrap the copper under the board accordingly to the circuit diagram and add 2 wires to links the pins.

Power supply:

up to 18V DC

We will use a single Power Supply Unit for the timer chip, the LED and the pump.

Step 4: Pumping System

The pump has been selected for the following reasons:

- supplied in 12V (not dangerous and compatible with the stroboscope voltage range)

- flow rate: 100ml/min minimum

- peristaltic:

It's more silent.
The liquid doesn't spill the mechanical parts (only the tube).

- price below 10€

- tube diameters OD5mm / ID 3mm. These dimensions are standard and new tube can be found more easily than 4.5mm OD.

Flow rate

We want to get around 25 drops / sec (Persistence of vision).

Each drop is 0.05ml.

Flow rate > 75 ml/min

We may need a nozzle to regulate the flow...

Step 5: Assembly

Be sure to have waterproof LED strip: it's not more expensive.

You may cut the 30 cm into two pieces, just be careful to cut at the right place (see tutorial).


Unlike other pumps, the peristaltic pump doesn't need to be below the surface of water (like low-cost pallet pump). It can suck water from above.


The casing should enclose the water drops fall.

The only light inside should be the light from the stroboscope.

Use dull black color to prevent reflection.


Step 6: Other References

A short notice on an Edgerton's Piddler device with a mechanical stroboscope

A detailed tutorial in french

Step 7: Commercial Product


Step 8: Some Tuning Is Required

First trial is not bad but the drops are not well separated...

- I'll add a nozzle to the silicon tube

- Direct output from the pump should be also the cause. So I'll try to built a container in between acting as a buffer