Paint Torch Reflector Black

[colinbm]

Yeah, but there are many new 365nm LED's coming on the market for curing inks & adhesives etc

I got one of those globes 7w 365 LEDs & it seems good, even though I don't have anything to test it on yet...

https://www.amazon.com/Lixada-AC100V-240V-Ultraviolet-Sterilization-Fluorescent/dp/B06XKS9KRK

[Cadmium]

So buy the Chinese LED bulbs then if you like them.

[colinbm]

How many turkeys does it take to fly 19 Conroys....?

[ulf]

Ulf

Are three 12volt batteries too much for these LED's that you have linked to ?

They are 50w & need 32-34V at 1400-1700mA.

Col

It very much depends of the batteries.

LED should preferably be driven by constant current.

[Cadmium]

How many turkeys does it take to fly 19 Conroys....?

 

 

I can only guess that 19 would probably require a turkey and a coturkey at least.

[colinbm]

[ulf]

Sure, nice idea, another untested Chinese product. Or maybe you have tested it?

I like Nichia LEDs, because we have tested them, and found them to be the best 365nm LEDs. A Japanese company, by the way.

 

No Steve, I am not stupid enough to suggest an untested product when to be compared to a Convoy 2S+.

 

The a Convoy 2S+ is very good as a single torch, but bundled is not that easy to handle.

10-20 start buttons and separate battery compartments to handle is not practical.

Painting the reflector with black paint is a real waste of optical energy too.

For energy conservation lining the reflector with PTFE must be better.

 

Nichia LEDs are still the best, but other brands are almost as good now.

The ones used in this array are good and with a similar spectral output and almost as good efficiency, verified with a spectrometer.

[Cadmium]

Ulf, looks good, you should do a topic about that.

[ulf]

Interesting points.

Sounds like that would require a "a pile of 18650" 3.7V batteries (8 to 10 of them?) just to get that turkey off the ground?

So it has its impractical side, and not exactly cheep ($72 for the LED).

Looks interesting

 

How can 8 or 10 18650 LiPo cells in a separate battery holder be less practical than 20 ones each sitting in its own sealed compartment in each Convoy?

20 Convoy UV torches and filters from you cost a tiny bit more than the total component cost for my "turkey" build too.

[Cadmium]

The a Convoy 2S+ is very good as a single torch, but bundled is not that easy to handle.

10-20 start buttons and separate battery compartments to handle is not practical.

Painting the reflector with black paint is a real waste of optical energy too.

For energy conservation lining the reflector with PTFE must be better.

 

It works great bundled, depending on how many you bundle I guess, but the 7 bundle seems quite easy to hold, not too hard to turn them all on.

It is just a test, but works rather well and will be what I use next time I shoot UVIVF, makes a very nice large wide beam,

with 7 you get the same light overall that you would have in the center of a single torch hot spot.

I like it.

Painting the reflector works the same as removing it, removes the hot spot.

I am not sure what exactly a PTFE lining would do, it might create some different kind of hot spot, it might not, it might not keep an even beam, it might, hard to say.

All I know if removing the reflector removes any hot spot, and grouping them makes a large strong evenly illuminated area, large enough most usual focal lengths.

The main point behind all this is not to use Convoys, but to test the whole idea of using the LED with no reflector, letting the light go wide and having no hot spot.

[ulf]

Ulf, looks good, you should do a topic about that.

Thanks,

 

It is a two year old design that I have not used very much.

The intensity is really good and the light pattern is wide and even.

 

If I should make something similar I would have designed it differently today.

 

My "turkey" can be powered with any DC source from 15-30V. A mains AC adapter works fine and I can run it on LiPo cells too.

I have ideas for a new design, but might not go along with it as the "turkey" works good enough for my needs.

[Cadmium]

Gobble gobble...

[ulf]

The main point behind all this is not to use Convoys, but to test the whole idea of using the LED with no reflector, letting the light go wide and having no hot spot.

OK, been there, done that. it works.

The LED-array must work better that a modified Convoy due to less losses.

Gobble gobble...

[Cadmium]

Why do you say loss? The only loss as I see it is that the LED is not right out in front, so the beam is limited to the angle from how deep it is in the tube.

That depth is the only loss compared to your arrangement. Just a loss of beam width.

The MTE has a 180 degree beam width, because removing the front puts the LED right out front. However, there is no good way to mount a filter in front of the MTE once the front is removed.

The beams of both the MTE and Convoy have the same brightness when the reflectors are removed.

There is no loss of brightness between no reflector and the painted reflector.

There is of course a loss of hot-spot (center brightness) when the reflector is removed.

[ulf]

I am not sure what exactly a PTFE lining would do, it might create some different kind of hot spot, it might not, it might not keep an even beam, it might, hard to say.

 

With PTFE you'll get more light as you are not wasting any by absorbing it with black paint.

The illuminated spot will be wider with a less sharp edge.

If a thin sanded or matted PTFE sheet is used, there will not be any hotspot. Maybe the PTFE-filter material used for WB could be used.

[Cadmium]

Maybe, but maybe it will change the evenness of the beam also, I would try, but I don't have any PTFE tube that would work that way.

Tube would need to be 20mm OD 18mm ID x 12mm deep.

The 'out front' LED idea is what I am really after, I don't want to use anything. The diving torch idea is similar to that, LED's are right out front, or very close to the front glass/filter.

[ulf]

Why do you say loss? The only loss as I see it is that the LED is not right out in front, so the beam is limited to the angle from how deep it is in the tube.

That depth is the only loss compared to your arrangement. Just a loss of beam width.

I say loss because all light hitting the black paint is lost.

You are only using the direct light traces from the LED.

The reflector is working like a mirror creating the hot spot.

If it is replaced with something having a diffuse surface you'll gain the diffucely reflected light too.

[ulf]

Maybe, but maybe it will change the evenness of the beam also, I would try, but I don't have any PTFE tube that would work that way.

Tube would need to be 20mm OD 18mm ID x 12mm deep.

The 'out front' LED idea is what I am really after, I don't want to use anything. The diving torch idea is similar to that, LED's are right out front, or very close to the front glass/filter.

Just line one of the reflectors with the filter material to test.

A conical shape out from the LED is best

[Cadmium]

I say loss because all light hitting the black paint is lost.

You are only using the direct light traces from the LED.

The reflector is working like a mirror creating the hot spot.

If it is replaced with something having a diffuse surface you'll gain the diffucely reflected light too.

 

That is what I said, there is a loss of the hot spot. Yes, I don't want any reflected light, I want only direct light from the LED.

Maybe, maybe not. Hard to say. A PTFE lining may create some indirect light that will change the evenness of the beam, some other form of hot spot or bands, or who knows.

All I know for sure if removing the reflectors removes the mirrored reflected light that cause the hot spot, and I find it hard to imagine anything will create any kind of reflected light that will be even.

I rather doubt it would be as even. I would test it, but I don't have any PTFE that would work in it.

[Cadmium]

Just line one of the reflectors with the filter material to test.

A conical shape out from the LED is best

 

A PTFE cone, well, more of a bowl shape actually, not something I am sure I can make.

 

Not sure it is a good idea. See it is the bowl shape that focuses the light to the center of the beam.

https://en.wikipedia.org/wiki/Parabolic_reflector

 

I don't think using a bowl design is a good idea.

Maybe I could try covering the reflector surface with Teflon tape...?

[dabateman]

Cadmium try wraping it in that plumbing PTFE tape. Used to lubricate fixtures. Doesn't everyone have that stuff around?

Might work and is thin enough to just line the cone.

 

Ulf,

That thing looks cool. I wonder how the output is compared to the bulb that Col and I have that he linked to. Ours is rated at 7W. Its uniform and I us it all the time.

Problem with convoy is the beam focus is too much and will wilt a flower on spot.

 

I may play with my convoy to see if Cadmium has something with either black paint or PTFE coating. I have the Semple 2.0 black paint now.

[Cadmium]

Yep, that's what I said :-)

I never forge the time Ben confused 'plumber's tape' (Teflon tape) with galvanized pipe strapping:

https://www.grainger.com/product/447P46?gclid=EAIaIQobChMI94O4osrk5AIVBdVkCh2argpKEAQYBCABEgJkk_D_BwE&cm_mmc=PPC:+Google+PLA&ef_id=EAIaIQobChMI94O4osrk5AIVBdVkCh2argpKEAQYBCABEgJkk_D_BwE:G:s&s_kwcid=AL!2966!3!50916758277!!!g!82128323877!?cm_mmc=PPC:+Google+PLA?campaignid=175663197

 

Anyway...

 

OK, going to try the Teflon tape, let ya know.

[Cadmium]

The Teflon tape covered reflector has a very hard to see slightly brighter beam (maybe?), and with no hot spots or otherwise uneven beam.

I can not see much difference with new fresh identical batteries, and there would be no difference seen in a camera comparison. Like I said "maybe", I might be imagining it now.

Fairly tedious to cover the reflector with the Teflon tape however... I would not want to have to do 7 of them...

Perhaps there is some paint on Teflon stuff, would be whole lot easier to do.

 

[Cadmium]

Here is a comparison.

[dabateman]

Very cool,

That photo is what I wanted to see 7 pages ago, before the turkey came in the room.

 

It looks to me like the PTFE is the best. I will have to do that now.