Longer throw without changing the driver !! :) Prototype is done and now it's time for testing.. ( more beam shots)

Never mind the science, common sense should tell you it would take longer to fill the bucket at 99% blocked.

I have always found it useful to exaggerate an issue to see it more clearly.

In electrical circuits, one can emulate a constant current source by having a high voltage power supply in series with a high resistor. For example a 300 volt source in series with a 300 ohm resistor will give 1 amp to a 1 ohm load. It will also give 1 amp to a 2 ohm, or 3 ohm load. In other words, it would appear to be a constant current source.

This water and hose example appears to be a constant flow source because the relatively high resistance of the length of garden hose. Within certain changes in the restrictions at the end it can appear as a constant flow source.

In the above electrical circuit, placing a higher resistance load it becomes apparent the the supply is NOT a constant current source. (a 600 ohm load will only draw 1/3 amp)

[quote=NightCrawl]

[quote=GottaZoom]

Our pump doesn’t care whether faucets are open or closed. It runs by timer because it is for irrigation and always has a form of pressure relief, regardless of whether the 2 garden hose faucets are open or closed. Thus it never has fixed pressure level, (unless I gate off the irrigation and close all of the faucets, in which case a pressure relief valve will open and hold pressure to protect the pump). Our system is more of a constant flow system, actually somewhat similar to the professors assumption (though we can tune for varying power, pressure, and thus output). Pumps generally won’t pump pressures greater than the system if it was built well. Generally a relief system is designed in (especially when built by someone smarter than me) to protect the pump and system. The primary risks in our system are a waste of energy and pump life.

Um… just wondering,can we go back to *my idea*and see how we can improve this idea into a better one? :Sp

Funny thing is you helped come to that conclusion by not opening the faucet all the way. Depending on other factors it might be different. It’s that complexity that keeps me asking questions.

While we practically cannot speed up light, most of us aren’t measuring speed. We’re observing volume in full or in part. Blocking the beam by redirection to change the locally observed volume is exactly the point of the thread. Sometimes an analogy is useful, if not exact.

Here’s a short video of a fresnel lens moving in front of an UF2100 running on 20%:

Quality isn’t the best because it’s a soft (flexible) lens and I just moved it with my hands. I left ambient light on to reduce brightness adjustments in my camera (compact camera, no manual settings)

However you see that it is indeed similar to a zoom light as there’s a position where LED and reflector are projected onto the wall. Near that position however there’s a position where that image is blurred into a quite good and quite bright spot.

Fresnel lenses are quite lossy, quite dome of the light is scattered at the edges. A real lens of same size would give a better performance, pot probably some more artifacts, too. Main contribution to throw is lens size and quality.
A high quality aspheric lens with same area and with a (bare) LED in it’s focus will have the best throw, but a smaller spot.

yeah, that was the base of my experiment, now i’m trying to move into adding combination of different lenses to see if i can manipulate lights into thrower or floodier ( for bike light)
i want to buil something like light device but in smaller scale :smiley:
maybe you can give me some input on these experiement, i found a success hooking my Trustfire WF 502B into telescope and it able to throw as far as 300’+, but the hotspot starting to dissappear and turn into a doughnut … but it still reach :slight_smile:
now… if i can somewhat miniaturize this device using combination of telescope optics ( which i have plenty of) that will be great

So, did you construct the apparatus as the OP described? From what I read just now, it would appear that the experiment wasn’t repeated.

By ANYone.

Sorry to butt in, but I take exception to misuse of the “S” word…

ALL of you could do well to revisit the Michaelson-Morley experiment right about now…

Waves don’t travel, particles do. Where do they all go?

I’m just sayin…

But I’ll go back to reading, it’s only page 4…

Dim

THANK YOU!!!

I was about to explode! :beer:

All I know is, I can throw my F20 a lot farther than it can throw back! :smiley:

Some of us “light is particles” crowd do seem to think that pulling all that light into one spot SHOULD push all those photons a lot further down the road…

Even if we “light is waves” types understand propagation of energy, and can actually draw the line for the Inverse Square Law…

Mainly, this is AWESOME to read!!!

8)

Dim

Don’t forget the reflective cylinder … :zipper_mouth_face:

Only if you put the LED at the exact point your eye would be. At least on my spotting scope that’s how it works. Ironically this “throw” works better with an XM-L (being closer to the exit pupil size), at least with mine. Try it through a rifle scope…

And yes, works quite well to put a very bright spot on something a long way away.

Now if I could line the barrel of it with reflective foil like the OP……. :nerd_face:

Dim

Uh…

I’d bet the farm that ma_sha1 can. :crown:

But it won’t be $15 any more!! H)

using binoculars won’t work too well, as they have 2 lenses spread far apart, the telescope experiment was using 2 lenses but they’re very close to each other :). if you using freshnel lens (magnifying glass) you will see the result similar to mine :wink:

then your horses aint gonna have barn anymore :wink:

Strange… Mine makes a tight, sharp-edged, white dot, which gradually gets bigger until I run out of room. My whole yard only lets me “throw” about 100’. And 13 seconds later I’ve wiggled my hand and it’s over. When the rain & cold let up, I’ll see if I can put this mess together outside somewhere…

And I have no idea what the “math” subtext is all about. I’m sorry I let it slip into my quote.

:weary:

Dim
(PS: you must be very calm, if you can use 15x binoculars effectively!)

I think it’s safe to assume he just used one lens set.

Of course, the 15x, while huge in binoculars, is just starting to touch most home telescopes’ power range. It seems the magnification should matter…

Speaking of which (and I note even you don’t mention the reflective foil anymore, which was all I could see of your apparatus until I read the thread) has anyone here ever looked at a Lighthouse? (yes, ma_sha1’s beamshots always make me think of them) They’ve been using Fresnel lenses for a long time. Maybe there’s some useful knowledge there? (especially if your aspheric sticks out & gets banged up)

Just thinking out loud…

Dim

What about the transparent cylinder and the reflective wrap? Or are the OP and the first photo still in play?

Not picking on you, scaru, just trying to get a handle on the crosstalk…

HAPPY NEW YEAR!! (I noticed your post time.) :party:

But wait… Did you notice the gobs and buckets of waste light billowing out of your apparatus??

I though you wrapped it in reflective foil…

That’s what I get for thinking.

And I’m half asleep already. I love the idea, the quick wit, and the clever effort. I especially love the way you defend your ideas. Nicely done (ditto for the rest of you, scaru, ma_sha1, and everyone else!! THANK YOU ALL!!!) (sorry I can’t remember all the names at 02:30) Now I’m going to go pull up the Michaelson-Morley experiment again & read myself to sleep…

Dim (and getting dimmer)

i only covered the front part of the tube…the waste light? you meant that “ring” light? it coming out from the edge of the device
i’m glad you find this reading amusing ,perhaps it will help lull you to sleep :wink:

Got us all. Same way. Glad he did.

AND a clever way to stir up a Very Useful discourse.

That depends. Have you seen a Fresnel with an aspheric profile ? I don’t know, but knowing how Fresnels are made, it seems only a matter of asking. There are many lighthouses which wouldn’t be there were it not for M. Fresnel. How many aspherics protrude enough to be a problem?

Good night all!

Dimmest.