Accidental turn on protection (electronic or mechanical)

Body is sealed, only waterproof USB charging port and 1 or to switches will be available to the user.

Just saw your post. Not much response. I guess caving headlamps and piezo switches are outside everybody’s budget.

I know Narsil or Anduril UI has electronic lockout (4 clicks) among other things. Lexel sells drivers with Narsil. They work with momentary switches (I think piezo switches are momentary but I might be wrong).

If you want to drive one 3V led with 2s you would need a buck driver which are a bit more expensive at 21$.

Or you can use 6V XHP50 and 2S TA Narsil (7135+FET) driver if you don’t mind direct drive (a lot of lumens and heat) at higher modes.

Would you mind sharing photos of the caving headlamp you built? I want to build mine in the future. I use a modded armytek and a modded nicron at the moment.

Here is a facebook post about my caving light https://www.facebook.com/permalink.php?story_fbid=860602017448780&id=100004969696221 more photos in the comments.

I changed my configuration to 2s1p pack and ordered two A17DD-L FET + 1 drivers I will try write new firmware for momentary switch and use one free attiny terminal to connect another FET for the spot led (no need for low current channel for it)

Nice build. Kinda looks like a smaller Phaethon that one of my richer caving buddies bought. Hope to see more photos when you finish.

But why xm-ls? I think high cri nichias, SST-20s or LH351Ds would make it lovier and would make those scurion beams look very ugly in comparison. Just a thought from a tint snob.

It is already finished, what kind of photos are you interested in?

It was my first built and I didn't had a lot of knowledge about LEDs and bins and it seems like XM-L2 are very common.

Also I thought that Nichias cannot output ~1000 Lm and couldn't find tight spot lens for the Nichia 219.
Are there any tight spot lenses for 219 or 351D?

How much current is going through the power-cable?

Or alternatively, is there an “enable” wire anywhere?

If possible, a magnetic-reed switch (mercury-wetted for lower contact resistance) could be completely sealed, and a magnet stuck near one end of it would “turn it on”.

Either get one with enough current-handling capacity to handle power from the battery, else a smaller one could be used for an “enable” pin.

You can find more tight lenses for nichia than for xm-l.
Nichia is smaller die and you can use any xpg/l optic.

If driver not have lock option you can add latching switch or inline waterproof switch like:

Are you sure for a17dd-l driver and your configuration 2s1p ???


One XM-L2 or three nichia 219 as Aswang recommend, so I guess about 3 Amps?

Magnets are very bad for cave survey (using magnetic sensors for azimuth), so I want to avoid any magnets.

It also need to be waterproof and these switches are quite expensive so I prefer to use only one switch for UI and locking, this is why I want electronic lock.

sorry my bad, it is 2P1S

I was wondering about it. Is any 3535 optic is compatible with any 3535 LED Cree/Nichia/Samsung can I use XP-G optic for XP-L2 LEDs?

Where can I buy these switches? Do you trust chinese counterfeits are they really IPX7?

Currently I am using APEM switches which are super reliable but expensive as well :frowning:

Yes you can use any 3535 optic. Degree depemds on each emitter die size.
Apem switch also have manufacture in china. This switch avalilable on aliexpress (topshall) and on other supplier. Is very good and is ip68!

Open magnets, no doubt.
If you “close the circuit”, you all but eliminate any stray magnetism. (That’s why toroidal inductors/transformers have almost zero stray field.)

So instead of, say, just taking a small Nd “pill” magnet and tacking it onto one end, you can take a thin magnetised rod, and put it in parallel with the magswitch so that the field “shorts” through the magswitch itself.

So unless you’re resting surveying equipment right on top of the magnet+switch, it should have no effect.

You initially said “electronic or mechanical”, so…

Anyway, by just snipping one lead to put the magswitch inline, then sealing the exposed leads, and having, say, heatshrink tubing on top of the whole mess (eg, also sealed with hotglue), you can make it impervious to water.

Oh, and don’t forget, 3A through a power cable will generate a small but looong magnetic dipole, unless you twist the cable (“twisted-pair”).

While I am searching for optic at Ledil or Carclo website some XP-G optics are missing from the XP-L2 search results, for example XP-L2 or Nichia 219 are not written as compatible with Ledill Tina-RS https://www.ledil.com/data/prod/Tina/10887/10887-ds.pdf

Somehow their website (and certificates) looks really suspicius

At first I was thinking about this option but electric lock seems simpler and more reliable, I also want to avoid accidental lock :slight_smile:


This is really good idea. I will use it!

Nice to see post has become more active. Nice inputs which could help me later on. With regards to optics does it have to be a specific size (diameter and height)? You can try also yajiamei optics for more options.

My experience with optics is that its best if you get a few different types and see for yourself the beam it produces and choose what you like or need. Optics designed for XML works for any 5050 or 3535 leds with 3535 leds producing a tighter beam. Personally I prefer beaded optics to produce nice beam with no artifacts. Clear tight optics gets you more throw but many times produce artifacts on the edges. For my caving lights I like the beam produced by 60° beaded combined with 20° beaded optics. 60° beaded + 20° clear also looks ok for me if more throw is needed.

I have a few 17mm and 20mm Yajiamei and a few more coming and I can test them if you like. I know I have some output and beam distance stats somewhere written I’ll try to look for them.

There are inexpensive, good, fully regulated buck drivers like the LD-29, or check here if in the USA for other options. No pulse width modulation crap and constant brightness on all modes independently of battery SoC (State of Charge).

At last and not really wanting to start a :-D fire, XM-L2 U2 emitters? Typical cool white low CRI stuff? :facepalm: In the darkness of a cave I think it is of primordial importance to have light of the highest quality. High CRI emitters of low to moderate (warm - neutral, 3000K - 4500K) temperature. Your more or less darkness adapted eyes will enormously thank the light temperature and color rendition to appreciate the details of your surroundings. Some CRI90+ candidates: Samsung LH351B 3000K and LH351D 4000K in this thread from AEDe (CRI90+ LH351D 4000K here in MTN Electronics too), CRI95+ Luminus SST-20 3000K & 4000K, Nichia 219C (various offerings in MTN Electronics too), and of course Clemence's shop, high CRI paradise.

Cheers :-)

Mon, 10/22/2018 - 03:34/06:17

I totally agree with Barkuti on light quality in cave environments. I learned about this when I used my little manker e03h as backup light and mini lantern while caving and since then fell in love with high cri leds (except CREEs). I highly recommend Clemence’s shop and his expertise in High CRI nichia leds. The E21As he sells have the best light quality I’ve ever experienced in an led light. His quad e21a setup would be lovely for your flood (mule) light. 3535 nichias are ok for spot/throw but SST-20s might be better (haven’t tried yet). I know Vinh at Skylumen uses the low cri 6500K version as an option for his GT mini build and his measurements show they out-throw xpl-hi for this setup.

It was my first built (before I knew this forum) so indeed I made a lot of mistakes :(

Since it begun as a driver thread and I have many more questions regarding CRI, Optics, UI and more..., which forum is the place for my caving light questions? LED Headlights? 18650 Flashlights? or maybe Flashlight Modding and DIY Parts?

No need to be judgemental, there's never good reason to be so.

I could say there are too much or too few forum categories, or maybe a restructuring need. I'd choose LED Headlights in this case, albeit you can change thread category anytime.

^:)