Replacement of carbide lamps by LED lamps

[Tobias Bossert]

Hi
I'm back again. Now I finished the 3-LED-testdevice.

Pause-Light
XR-E WD R2 and Carclo 10170 and internally etched glass lens @50mA

Work-Light
Diffus-part: Same XR-E WD R2 and Carclo 10170 and internally etched glass lens @150mA(low)/250mA(high)
plus
Light-up: One die of MC-E WD M and Carclo 10195 and clear glass lens @30mA(low)/125mA(high)

Hall-Light
All four dies of same MC-E WD M and Carclo 10195 and clear glass lens @4x750mA

Shaft-Light
XR-E WC R2 and aspherical glass lens 21,5mm dia x 20mm fl @1150mA

In the lab it works similar to the former 4-LED-testdevice.

We will test it at the weekend 8/9 August in Hirlatzhöhle - I will post some results, shure.

If this new test device holds what it promisses in laboratory, I'm finished developing a reasonable headlamp for big caves. In this case I will post circuit diagram, layout and mechanical specifications, so everyone can build such a lamp by its own. It's rather for self made man than for commercial manufacturer. But may be there will be some manufacturer taking the ideas and developing a commercial device from it - would be very interesting!

We started a poll on our caving club website to find out the wishes and requirements of cavers with respect to helmet lamps.
http://www.hirlatz.at/umfrage/fragebogen_en.html
The more cavers participate, the better the data basis to develop new improved headlamps.

Regards Tobias

 

[morow]

*Edit for readability - sorry it was in paragraphs when I hit submit I promise!*
I am working on designing a dedicated caving headlight as well. Right now I am looking at using 2 Endor Rebel stars with 3 emitters on each.

Flood - I plan to use one star with a very wide angle reflector and either frosted glass or some other diffusing coating/film. I want a wide even spread. probably about 150 degree. A fairly strong diffusion would be necessary using any small reflector with these due to the widely spread emitters.

Throw - The second star I hope to test the available 20 degree colmenating lens. This will be more for lighting up wide passages then a narrow beam to spot deep pits. Until I test it or see a review I am concerned about the throw pattern, and efficiency. I doubt it is much over 85% efficient and could be worse. For controls I am planning a 4 position switch.

1. off
2. Flood only - set at about 35 lumen or less. This is my resting or break time setting. I don't need any distance lighting, and am very concerned about glaring my companions. We will often be facing each other or consulting a map or such.
3. flood and Throw in parallel - set around 150 lumen. This setting will be my most used for moving about the cave. I hope the combination of flood and fairly wide throw beam will give good coverage for all needs.
4. Flood and Throw in parallel- set around 600 lumen. For large rooms and distant targets. This setting would be used only in short bursts. Taking into considerations losses in the optics I shouldn't need more then 1A of drive current to hit my #4 setting target. I could do this with a single externally dimming driver using multipole multithrow switch(s) and resisters.

I don't often get the chance to do very deep pits, so a narrow beam is of little use to me. The farthest I need to project is typically 300 feet at the most and often well under 200 feet.

Concerns and thoughts.

I wonder if 2 additional settings would be handy. 1. A setting between #2 and #3 above for close in work. Something around 70 lumen for small passages. Probably a combination of Throw and Flood. 2. A stronger distance setting dedicating the full 1A of current to the Throw. Of course if I only intend setting #4 to light up the big rooms the flood may not have much effect at all. I could just drive the Throw in setting #4 and be done with it.
I plan on mounting the batteries to the back of my helmet. I am looking at LiFePo batteries for a compromise in safety, energy density, and voltage. Running the batteries at 1/2C for only short bursts and at 1/8th C for extended times I think I can safely shrink wrap then rubberize the battery packs for safety and water resistance.

 

[TorchBoy]

Pleeease use paragraphs, morow.

 

[morow]

O, I like your idea of the down angle light for close in work and lighting up the area infront of your feet without having to swivil the entire headpiece. It would be nice to have a usable light without the need for an hinge to move it up and down. Less complex and it would probably be easier to keep the weight close to your head and limit how far out the light extends.

In my use I normally swivel up/down my light when I need to look at something close. I don't think I often need to swivel the headlight to spot a distant object. So a flood pattern like you have works for looking forward and down.

 

[TorchBoy]

Wow, morow. So much more readable. I like the different LEDs (and optics) for different uses approach, and I'm slowly working on something like that myself. I take it that you and Tobias don't find that frosted/etched glass cuts down the intensity too much?

Tobias, I've just filled in your survey. Thanks for an English version!

 

[Tobias Bossert]

Hi all,
last weekend we took some photos in Hirlatzhoehle to compare the new Testdevice_3 using a 3-LED aproach with the old Testdevice_2, which used 4-LED approach.
You can see this at http://www.hirlatz.at under 'New comparison'.

There is still the 'Old comparison' too, but we changed the layout a little bit: Now its on a dark background, because the photos are dark too.

As you all know now, I'm not expert in machine-made bombproof cases. But I'm glad I that got what I got - handmade without machines!

My fingers are for demonstrating the size of the device

The dimensions of the case (without knob and cable-feedthrough) are 86mm x 56mm x 24mm. The wight together with 1m cable and connector is 140g.

The real-world-test in the cave resulted in some minor modifications to be done - thats the reason why it takes one week to come up with this posting.

The changes at the cirquitry are done now, so I can post the circuit diagram and description for everyones free use:
http://www.bossert-inet.de/tobias/Circuitry_Testdevice3.pdf

The layout of the small motherboard will be changed too, so I'm posting it later.

The case is a Hammond 1591 XXM, which I deformed termally with a selfmade molding press. I will have to change this molding press too, because I got problems with sealing the lenses.

It is prooven now, that we can combine the Hall-Light and the light-up part of the Work-Light. When you compare the beamshots of 'Old testdevice 2' with 'New testdevice 3' you will see, that the old Hall-Light was a little bit better. But any Hall-Light is luxury anyhow, so I optimized the compromise towards a good light-up of Work-Light.

Work-Light has two levels: low and high. Distance to forground doesn't change much with room size, therefore the diffuse part of Worklight is increased by 66% (150mA to 250mA) only from low to high. But distance to background changes strongly, thus the light-up part of Work-Light is increased by 300% (30mA to 125mA).

Some cavers accompanying our photo session last weekend think, that it would be sufficiant to have Pause-Light, Work-Light low and high and Hall-Light. They proposed to leave away Shaft-Light completely.

If so, the lamp would be reduced to 2 LED only.

But I myself like to have a narrow thrower. This is not new idea of me, since I hand-made my first "Halogeny" in 1978, as you can see here:

Fully regulated at that time!

One caver proposed to switch to a TIR instead of the px glass lens. O.K. this will result in a higher lumen output, because all light not reaching the px lens is waste, that's true. TIR like Carclo 10199 (or 10048, the maximum size I could use in this small case) provide soft edges and a litle bit of spill, so you will recognize the surrounding too. He thinks, this would be better. But personally I think:

• If the shaft is narrow, than any spill will annoy you
• If the shaft is wide, than why not using the Hall-Light?

As you can see, it's unpossible to satisfy everyone: That's life!


Next to do?
I will correct the motherboard and the molding press and than 'produce' about ten samples.

Why?
These ten devices will go to active cavers at cost price and without guarantee. I hope these cavers work as multiplicators. If so, than more and more cavers will demand such optimized light distribution - and at the end some professional manufacturer will produce commercially machined helmetlamps providing good pattern.

All parts together cost about 150€ at the moment, cost of labor would be much much higher, because all is handmade.

I hope you enjoy the beam comparisons, they are much more meaningfull than beamshots onto a white wall.

Regards Tobias

 

[Tobias Bossert]

All clear

Now it works.

The reason for this confusion was:
We developed the site and tested it with Firefox 3.5.2 only. It worked correctly. Than I gave the link in post #126.
Only some hours later we got the information that some text in the tables is black and some tables ar much broader than the frame when usin MS IE8. Oh MS!
Than we looked for a work around under time pressure. Gottfried found it - but with these multible cut and past he copied the wrong table.
Now it works fine - and we know, that we got the better browser with Firefox...


Attention

We got some confusion in the table for Scurion P4 at the 'New comparison'
The pictures are not the right order at the moment.

I will give the all clear when we have solved the problem.
Hope it will be soon...

Tobias

 

[patudo]

Hi from Spain :

I haved read your post very slowly(my english is not good) but i understanded every each word. The planification is espectacular and i hope you will arrive to the perfect cavinglight. Here in Valencia (Spain) i am working with standart leds(seoul p4) regulation cards and Li Ion batts 18650. I wont emulate the carbide light i am looking for a new kind of light, but it is hard.

Notice that, never the light movement has got this trubble since its creation by Edison. It's a new light world into our cave world. We are pioneer and selfcontructers, that is the esence of the right caving people.

Nice to talk you i hope i can help you in the future, and cave togheter.

Carlos Vergara Speleological Society La Senyera. www.espeleosister.com

 

[TorchBoy]

All parts together cost about 150€ at the moment, cost of labor would be much much higher, because all is handmade.

:thinking: I'm struggling to figure out where that cost has gone to. Would you care to elaborate?

Edit: I'm reminded of John Harrison, who went on inventing marine chronometers until he came up with a design that could be manufactured comparatively inexpensively.

 

[Tobias Bossert]

:thinking: I'm struggling to figure out where that cost has gone to. Would you care to elaborate?

Hi TorchBoy
if you are a prifessional than you are allowed to struggle:
I calculated all costs on base of enduser ordering one part only from each type and having to pay tax (in Germany 19%) and postage.

The most costy part is the rotary switch 6x2 with IP68: about 30 Euro
Next is MC-E WD M with about 25 Euro
Two XR-E WD R2 together about 15 Euro
Motherboard about 12 Euro
Glass lens about 8 Euro

The sum of only these six parts is even 90 Euro!

In case a manufacturer starts a serial production, these parts will be much cheaper at quantities of hundreds. For me the total sum of all parts are just below 150 Euro; I guess a manufacturer can get them all for half this price.

But remember please:
I definitly do not plan to produce this lamp commercially - so the costs don't matter for me. I'm happy being able to demonstrate that light distribution can be improved dramatically.

 

[Tobias Bossert]

One caver proposed to switch to a TIR instead of the px glass lens. O.K. this will result in a higher lumen output, because all light not reaching the px lens is waste, that's true. TIR like Carclo 10199 (or 10048, the maximum size I could use in this small case) provide soft edges and a litle bit of spill, so you will recognize the surrounding too. He thinks, this would be better.

O.K., let's look what we can do...

I gathered some "narrow beam" optics and build a device to compare them under real world conditions. Here it is:

That's no well designed model, it's simply a device to make some comparative tests.

The optics are as follows:

1. Spherical pcx glass lens 21mm (Anchor Optics AX77183), 20cm diam. at 1m (11°), scharp edge, rel. center brightness 100% (referenz, this is the lens of testdevice_3)
2. Aspherical pcx acrylic lens 24mm (DX sku:4614), 30cm diam. at 1m (17°), scharp edge, rel. center brightness 52%
3. Aspherical pcx glass lens 28mm (DX sku:5297), 49cm diam. at 1m (27°), scharp edge, rel. center brightness 29%
4. TIR 20mm plain thight (Carclo 10199), subjective ~35cm diam. at 1m Entfernung (18° subj.; 8° spec.), rel. center brightness 82%
5. TIR 20mm frosted narrow (Carclo 10200), subjektiv ~26cm diam. at 1m (15° subj.; 10° spec.), rel. center brightness 59%
6. TIR 26mm clear (L2 OPTX1006), subjective ~20cm and ~40cm diam. at 1m (11° / 22° subj.; 20° spec.), rel. peak brightness 103%
7. TIR 26mm diffused (L2? Ledtech LT-1452), subjective ~30cm diam. at 1m (17° subj.; 16° spec.), rel. peak brightness 82%
8. TIR 26mm plain thight (Carclo 10048), subjective ~28cm diam. at 1m (16° subj.; 6° spec.), rel. peak brightness 117% (points) and 71% (middled)
9. TIR 26mm frosted narrow (Carclo 10124), subjective ~28cm diam. at 1m (16° subj.; 11° spec.), rel. center brightness 81%

Here you can see comparative beam shots from these 9 optics.

The device doesn't look so nice, because all those optics were fixed with silicone. There is a severe reason for this:

I first tried to use the original holders as intended. But it worked very bad.
This was a new finding for me, since in past I always used the original holders to center the optics. But in past I always used frosted or rippled wide or at least medium - and whith those broad angled beams adjustment doesn't count so mutch.

So I had to adjust every optic manually. I modified all holders to allow adjustment of at least 0.5mm in every direction. This helped dramatically.

As an example I show you Carclo 10199/10425 without modification (above) and with manual adjustment (below):

In this case the x/y-centering of LED and optic was already o.k. but the size of die images from TIR and from center lens was different. Therefore an adjustment in z-direction was necessary by about 0.6mm, that means I had to get the LED out of the optic by about 0.6mm, to acieve maching sizes of both images. This smothed the beam pattern but increased the spot fom about 10° to about 18°.

Result: Carclo 10199 may be optimized for lambartian sources but gets problems with the primary lens of Cree XR-E.

In principle, such corrections were necessary with all six TIR I used. Sometimes also adjustment in x/y-directions were neccessary too.

I realized adjustment by putting the holders into a bed of silicone on the starboard. As you can see, with some optics I didn't found an optimum adjustment. Additionally the adjustment somewhat disappeared during drying.

At the end I came to the conclusion:

• You can use the original holders with medium or wide beam
• You'll have to adjust the optic manually for narror beams

With pure lens no such problems arise.

Now this device with 9 optics is on the way to be tested in Hirlatzhoehle, I'm interested which one will be testers first choise...

 

[Tim]

Hello Tobias,

First i would like to felicitate all members in the forum that have participate activily in this thread.
I am triyng to devolope a headlamp but using just 2 LED. and my perference go to MC-E Warm white.
In the devolop 3 i do have some questions...
Where do you put all the drives, with such a small box?
Why dont you use just one drives and use mosfet as switch is less space and power lose in driver.
I would like to help you in the electronics part if you want, need!
I will include in my project a power meter with 5 LED to see how much power remains in the battery and a PWM for power control the drives with a microcontroller.

Tim

 

[bordali123]

Hello,
there is another lamp on market with much lower cost than Scurion.
http://www.spelemat.com/ledlampe/
Maybe you could make some comments.

 

[Tobias Bossert]

Hello,
there is another lamp on market with much lower cost than Scurion.
http://www.spelemat.com/ledlampe/
Maybe you could make some comments.

Hi Bordali123,
this lamp is new for me. There are not enough technical specifications on the web site, so I can't say anything about its features.

• It has a modified standard case, making it cheaper for small series.
• The user interface seems to be similar to that of Scurion.
• The 'room light' is not as wide as Scurion - this should result in less power consumtion during worklight (may be similar to my testdevices).
• The thrower looks similar to that of new Scurion K, I don't know the beam pattern at the moment.
• As with Scurion you can combine flood and throw - but I don't know how good both sources will complemet each other (this isn't optimized with Scurion).
• Both beams are concentric and thus there will be no effect 'light in the foregroud and light in the background' at same time without realizing a two-beam-pattern all time.

At the moment I know nobody who owns this lamp, therefore it's unpossible for me to make meaningfull comments on it.

We have to wait untill this lamp is tested by somebody...

Regards
Tobias

 

[Tobias Bossert]

I am triyng to devolope a headlamp but using just 2 LED.

Hi Tim,
as some testers in our club claim too, two LED would be sufficient and the shaft thrower ist not necessary. So you may be on the right way with your two LED project.

my perference go to MC-E Warm white.

I know many cavers prefering warm white instead of cool white (there is normal white in between). But this doesn't realy make any technical difference, since you can decide which color bin you put into work at the end of producing the sample - all other parts are totally independent of this decision.

Where do you put all the drives, with such a small box?

Please wait for some weeks, I'm developing a complete set of documentation of testdevice_3 at the moment in parallel with building ten samples of it. In this documentation you will see how I managed it to put 5 driverboards, my mainboard and all three optics inside this small box...

Why dont you use just one drives and use mosfet as switch is less space and power lose in driver.

Because it's easier for me to use five complete driverboards than to develop one universal type and switch (and split) its output to several LEDs. But you are completely right: This method is unuseable for a professional manufacturer producing high counts of devices.

Thank you also for offering help. At the moment I definitly do not plan the become professional manufacturer and for my small count of samples, I found a practical way to realize it.

I will include in my project a power meter with 5 LED to see how much power remains in the battery and a PWM for power control the drives with a microcontroller.

This will work with lithium rechargeables only...

Regards
Tobias

 

[Tobias Bossert]

Now this device with 9 optics is on the way to be tested in Hirlatzhoehle, I'm interested which one will be testers first choise...

And now it's back again.

The testers say that with a strong and not too wide Hall-Light indeed a Shaft-Thrower is unnecessary. But Hall-Light of 'testdevice_3' is additionally used as light-up for Work-Light and therefore needs to be wide enough (I took a frosted medium with more than 25° FWHM). This is optimum for combination with the diffuse part of Work-Light and good as Hall-Light too but too wide and too much spill for looking into deep pits.

The testers disliked the Shaft-Thrower of my original 'testdevice_3' because it is too narrow (10° FW). That was the reason I gave them the device with 9 different throwers to test.

Result:

• All lense optics and 'plain tight' TIR are better than the 'frosted' ones, because frosted optics produce to much spill far apart from the center of the spot
• Other than I predicted, the beam should not be narrow but more like medium (15 to 20° FW instead of 5 to 10° as I thought)
• The thrower should provide a reasonably flat pattern inside the beam and than fall down at the edge rapidly but not with too strong edge on the other side

They say, the beam shots I posted have no direct correlation to the subjective sensation when used in real cave. The sensation much more depends upon the spill and the pattern outside the 'half maximum angle', which you can't see on those beam shots.

The first choice was #4, Carclo 10199 20mm optic plain tight for XR-E, displaced mechanically to align both images (from internal lens and from internal reflector).
Estonishing... not the same as I thougt looking to the white wall in my cellar!

I will follow this finding and replace the lens by that TIR for the 10 samples I'm producing now.

 

[Tobias Bossert]

I would like to help you in the electronics part if you want, need!

Hi Tim,
I'm producing 10 samples of modified testdevice_3 at the moment. This takes me much time, because I'm preparing in parallel complete documentation of the whole lamp. One part of that documentation is existing at the moment but naturally is still preleminary. I give you the actual version; please realize that this may change until publication!
http://www.bossert-inet.de/tobias/Circuitry_of_Helmetlamp.pdf

In this document you will find other links to the board layout too.

The circuitry uses either Kennan_II (PT4105) or Kennan_II (AX2002), but for my application with dimmed output the old PT4105 is much better, as you can see here:

http://www.bossert-inet.de/tobias/PT4105_vs_AX2002.pdf

I still had left 17 Kennan_II and 3 Kennan_I, so I can produce all 10 samples with PT4105 boards. But afterwards these are gone! Since PT4105 is discontinued and I dislike AX2002 for that application, I will need an alternative.

You offered to help me with my electronics and proposed to use one converter only and distribute the currents to the LEDs via MOSFETs.

Do you know a DC/DC converter delivering an output voltage of 3.5 to 4V suitable for an output current range from 50mA to 2.5A? Minimum current is during Pause-Light, maximum is for Hall-Light.

All circuitries I know so far provide poor efficiency when loaded with 2% of max current only!

Regards Tobias

 

[TorchBoy]

The testers disliked the Shaft-Thrower of my original 'testdevice_3' because it is too narrow (10° FW).

That's interesting. I use a 5° aspherical lens-focused beam for shaft throwing because I've found 8-10° from a TIR optic is too wide to have really good throw. Maybe we mean different things by "shaft thrower"; I doubt our shafts are bigger. Maybe they weren't actually using it for shaft throwing.

 

[Tobias Bossert]

That's interesting. I use a 5° aspherical lens-focused beam for shaft throwing because I've found 8-10° from a TIR optic is too wide to have really good throw. Maybe we mean different things by "shaft thrower"; I doubt our shafts are bigger. Maybe they weren't actually using it for shaft throwing.

I'm with you completely. That was the reason I used aspherical lens with testdevices 1, 2 and 3. Starting nearely focused so that the rectangular structure of the die was just gone (about 5°). Than after some criticism of the testers I defocused it so that there was just no increased intensity at the edge (about 8°).

I think you are right, they didn't used it for really narrow deep shafts during testing indeed! It seems they tested it rather in big halls with infinitly high ceiling or in very large canyons, which you can find more oftenly in Hirlatzcave than narrow shafts.

O.k., that will be up to the manufacturers to decide whether to implement a thrower at all and of which type if so. The most important thing of my work is the combination of flood and soft throw to a usefull worklight. I would be happy if some manufacturer would adopt this strategy, independently whether he adds a thrower or not.

 

[uk_caver]

I'm just wondering how efficient the aspherics are at capturing light from the LEDs - does much light miss the lens?