need help here.. 1

[NastyShinta]

i have watched this video and i want to know how things happen. how did they compute the pressure and flow in each pipes and the control they used. what type of valve did they use to close/open the pipe?

any help is appreciated.

http://www.youtube.com/watch?v=3yLPkveoJgw

 

[MikeHalloran]

If you wanted to spend a lot of money, you could do it with a PLC, but I'm guessing the 'control' is probably a programmable LED array controller, you know, the kind that run moving message boards. You could demultiplex its output at the row and column drivers, or just glue a phototransistor over each LED in a message board.

In either case you need a rack of interface cards to drive solenoid valves, that are fed with water at constant pressure and discharge through tubes of constant length and diameter. In this case, the water supply pressure is just a couple inches of water, which you could do with a standpipe spilling any water you didn't need from the supply header for each row of valves.





Mike Halloran
Pembroke Pines, FL, USA

 

[NastyShinta]

if im goin to use a PLC, ahm, what kind of valve will i put on each pipe to let the flow? also,how will i goin to compute the water flow/pressure from a pipe(assuming i will divide the main pipe into 7 branch and this 7 branch will subdivided into 25 pipes.??

 

[MikeHalloran]

Mock up one bit with a solenoid valve and some copper tubing. When you get the shape of the fountain like you want it, measure the flow with a bucket and the supply pressure with a gage.



Mike Halloran
Pembroke Pines, FL, USA

 

[NastyShinta]

For example i have this block diagram with specified number of pipes with a valve that has a specs given, how can i compute for the main pressure from the pump?

 

[MikeHalloran]

In the block diagram, I see 7 solenoid valves serving as row drivers.
I don't see see how the "noozles" interface with the column drivers.

What valve specs are confusing you?



Mike Halloran
Pembroke Pines, FL, USA

 

[NastyShinta]

ahmm...for example, each of the 7 pipes will be divided again up to 15 small pipe with a noozle specs given in the picture.



how am i suppose to calculate each line pressure and the main pressure needed for the motor to support when all the valves are open..

 

[MikeHalloran]

Why are you posting images of text from printed material?
Couldn't you just transcribe the text?

( My conjecture: You have found a commercial source for the object you seek You are having difficulty comprehending the material well enough to copy it on the cheap, which is your unstated intent. )

The text appears to be part of a catalog sheet for a nozzle. Or perhaps for an array of nozzles; the stated flow seems a lot for the stated head.

Why don't you post a link to the complete catalog page, so we can understand the context that is giving you difficulty?



Mike Halloran
Pembroke Pines, FL, USA

 

[MikeHalloran]

Let's back up a bit.
The video shows a clock/message display that can display at least 8 ASCII characters legibly.
Dotwise character displays like that require a 5x7 matrix per character, so there are at least
8 x 5 x 7 = 280 possible dots, or discrete fountains, if that's how it's done.
I.e., doing it the obvious way, you need 280 solenoid valves, and associated drivers.

Something about the video suggests that _maybe_ it's simpler than that, i.e. at each 'dot' there is some kind of fluidic AND gate, in which case the display would need 7 row driver solenoid valves and 8 x 5 = 40 column driver solenoid valves, or only 47 valves (not necessarily all the same size) instead of 280. Frame by frame examination of the video file, or a few random stills with a reasonably fast shutter, might confirm or eliminate that possibility.



Mike Halloran
Pembroke Pines, FL, USA

 

[MikeHalloran]

So I poked around a little.
There is a US patent, # 4,111,363
... for doing it the hard way, with many many valves.

The patent shows you how to build one for yourself. Programming it is an exercise left for the student...



Mike Halloran
Pembroke Pines, FL, USA

 

[MikeHalloran]

Additionally, half a dozen patents reference that one. Some of them are also for variable message displays, presented in interesting ways.
Check out freepatentsonline.com.



Mike Halloran
Pembroke Pines, FL, USA