D.I.Y. Illuminated tailcap

Yeah when I’m putting the pin in the bottom board I just only put it halfway in the via and solder it there so it isn’t anywhere near the surface on the other side. Does that make sense or are we talking around each other?

Yeah, same thing I plan on doing. Although I think I will cut the pin next to the “plastic spacer” on the pin to the right length to make things simpler. Or you can slide the plastic piece down a bit until it is at the right height.

I have to say, these are an amazing idea and work good. Just a matter of dialing in the components.

I think that since all the TA drivers use the same components it should be entirely possible to figure out a parts list for a “build and play” lighted tailcap.

On your pots, do they spin all the way around endlessly? repeating the same range each revolution? Or do they stop at the highest and lowest points? All the larger pots I have used stopped spinning (or clicked) when it reached the end of the adjustment window, thats one thing that is making this so hard.

Yes, with a dead spot of zero throughput at the end of each revolution

Ok, I was playing around with a whole light a bit more and it seems to have “gained mode memory”.

Basically short clicks work fine but even after 10+ seconds it will still come back on as if it was a long click (aka, one mode lower). Very strange.

This one is pulling about .4ma. A sign of needing a higher resistance bleeder?

Lower resistance bleeder.

What lvp resistors are you using?

Lower resistance, interesting. Seems like the OTC is staying charged which would seem to be due to it getting too much trickle power.

It is using the normal 19.1k/4.7k LVP (22k works but 19.1k is already calibrated and it lands more in the middle of the calibration table).

The tail can’t get enough power through your bleeder so it is pulling power through the MCU/OTC … at least that’s the theory.

Either way more bleed should fix it, although decreasing tail current would be more ideal

Makes sense. I will try dropping the current and see what happens.

Swapped the tailcap to the 6x red @ .22ma and it looks like it is working properly again. So yeah, just have to dial in the current to the bleeder resistor.

Now to figure out what current I want and what values it needs.

Thanks for this great idea!

I have noticed that ever since I got the S2 it is the one that everyone grabs when they don’t need the big monster lights.

Ahh, I do love my S2(s) - carrying one right now. I have all the parts to do an illuminated tailcap now, but my worn out soldering iron wasn’t up to snuff. Ordered a new one (Aoyue 469 + genuine Hakko T18 tip), and it’s sitting at my house while I’m down in Austin, TX for a conference. Can’t wait to get back and try assembling it again.

Putting these together was actually quite nice and easy. Just the little things that needed to be sorted.

I really like scientific data for things is my real problem, I like knowing it is the best possible setup.

I am thinking about putting together a tailcap on a breadboard later and experimenting with the resistance and current draw to see what kind of brightness of various color LED’s put out.

I was looking at these last night and if I just give up on them looking cool during the day (although it makes me rethink that tiny13 enabled board again, oh the options) then somewhere in the .10-.20ma range seems to be about right at night.

What kind of current are ya’ll generally using?

Hmm, BG is now selling the X5/X6 illuminated tailcap, ready to roll. Of course this is the Gen1 style and you’d probably still need to add a bleeder. But might be an easy way for someone to get off the ground. OK, and being Gen1 style, you’d need a translucent spacer, too. OK, maybe won’t be too useful… oh well

Thing is, by buying that part you will have avoided nothing: you still have to experiment with bleeder resistor values and perhaps even tail resistor values, you still have to solder tiny components.

Definitely agree, djozz! Just thought it was worth mentioning, and tried to highlight those issues.

Though if you consider buying the boards and LEDs, if you only plan on doing one, this would be a cheaper route. And while you’d still need to solder small components, it’s only one instead of several (assuming tail resistors are OK).

Ok, I need to correct myself. I made a few mistakes. PD you were correct in your statements.

I broke out the good equipment today instead of the harbor freight meter and ran some tests in a dark room.

Basically I could not see the LED’s glowing due to the direction they were pointed and the meter read 0 so I assumed it was not on. Turns out the meter was simply not sensitive enough.

Once I hooked everything up properly I noticed that I do actually have lit LED’s for most of the adjustment range up to 50k. at 50k it is pulling around .03ma.

What threw me off was that in the first ~5k of resistance (a mere hairs turn of the pot) the current would go from ~20ma down to .5ma. It appeared to turn off at this point as after reaching about .25ma at around 10k ohms it was a very slow drop down to .03 and was hardly noticeable.

I was basically only noticing the first 5k-10k worth of change as it was so sudden, the rest happened so slow comparatively it appeared to not be on.

I think going forward I am going to install a fixed resistor instead of jumping the pads on the top board. Something like a 4.7k-10k since I have a ton of them already. This will limit the max current to something like .2-.4ma depending on the LED VF based on my early testing (still need to try red, white and blue).

This would mean that even at it’s brightest it should not effect the driver with a 560ohm bleeder and then can easily be adjusted down to whatever I want.

Sorry I wasted your time, I should have finished testing before posting.

I can also see why you say that a bright tailcap is not needed, if you just forget about how it looks int he day a dim tailcap is still usable at night.

TA, I’m glad you’ve posted what you have. It reminds me of Edison and the light bulb… you learn a lot on the way from the “failures”. By sharing your experiences, it helps guide the rest of us!

I would probably have more bright ones if it wasn’t such a big power sucker. I keep them dim so I don’t have to lock them out on my shelf.

Glad it’s working out for you

Yeah, I always find it annoying when you find an old thread with the same issue you have and the solution was never mentioned.

I hope to get a basic rundown of resistance needed to limit current to ~.5ma for a fixed resistor with various colors.

This should ensure that the sudden drop in brightness and the driver issues are no more and give a nice wide adjustment range from .5ma down to ~.03ma.

Yeah, I was also worried about the drain over time but I also am very careful with my lights and charge them up after basically any use. It is rare for a cell to enter the charger will less then 3.5V rested. They look so pretty glowing on the shelf!

That said I think that .5ma is enough for even this and anymore is wasteful, so capping the current there would make things simpler all around.

Plus I would like to find a parts list that is known to work together with the TA drivers and put it in the TA thread is that is ok with you. That way it makes things easy for people to build and use the lighted tailcap and TA drivers together.

Sure, go ahead

I know my answers are buried in this thread, but there are just way too many pages. Trying to take what I can from the original post, though. So Gen2 is more efficient. Makes sense since not using the clear spacer. I want to buy all the parts to do my first cap on an F13 which I believe has a 20mm board. Am I correct in that I can use the stock switch board and just need the top board?

The largest board looks like the 19mm BIG SWITCH. Also, am I correct in that the large switch is not equipped for use with pots?

Appreciate all the time PD and everyone has put into this. Making a list of parts now and will post them before making the purchases.