dual stage twisty mechanics?

A little confused about how the twist to change to turbo mode works. I recently purchased a tk11 at the Swamp meet for $15usd. I was looking through it and figured I can change the LED and switch. The only thing I couldn't figure out was the driver and how they work when fully tighten.

I'd like to keep that same interface when upgrading the driver to keep the xp-l emitter running at 3 amp

Dumb question, but how do the twisty switches really work?

i know you twist it to change on/off/mode etc.

my question though is more basic

why isn;t the light on all the time?

does it have some kind of combination threading?
that is, for instance partially anodized/insulating and partly bare/conducting?

what happens over lots of cycles, does the anodizing wear off and you can;t turn it off?

or is there some kind of pressure activated switch that doesn;t depend on thread contact?

also if they turn on by tightening, that means that they are not tight when off, ie in your pocket.

so what stops them from unscrewing all the way?..

..or tightening and starting up in your pocket, potentially on high/hot mode...?

wle.

Re: Dumb question, but how do the twisty switches really work?

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Re: Dumb question, but how do the twisty switches really work?

A lot of twisty lights simply become too long to contact the positive contact on the battery as you loosen the head.

Norm

Re: Dumb question, but how do the twisty switches really work?

1. The light is built to break contact when it loosens. You can poke around with wires to find out: Either the threads are anodized, or only the 'contact ring' around the driver is the contact. Wearing all the anodize off is tough - HAIII is aluminum oxide, AKA corundum, AKA sapphire. You'd have to grind through a lot of thread to touch metal to metal.

2. See 1. The threads usually are either both anodized, or it doesn't matter.

3. Anodizing is tough to wear out. Most light designers don't depend on the threads.

4. It's almost pressure-activated. If you make a 51mm capsule shrink to 50mm long, it suddenly makes contact on a 50mm-long AA cell.

5. Yes, common twisties are loose in your pocket. The O-ring helps to keep the parts from wholly unscrewing. Severe vibration will allow it to turn anyway.

Re: Dumb question, but how do the twisty switches really work?

Actually, it's Elfin magic.

Re: Dumb question, but how do the twisty switches really work?

Bob Damon said:

Actually, it's Elfin magic.

Click to expand...

+1 lol


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Re: Dumb question, but how do the twisty switches really work?

silly me.
2 degrees in EE and i thought the actual switching mechanism was in the threads
not!
carry on..

wle

Re: Dumb question, but how do the twisty switches really work?

Ahh sorry its not Elfin magic. everyone knows the only twist off cookie is the Oreo .

Re: Dumb question, but how do the twisty switches really work?

There are to my knowledge 4 types of twisty light mechanisms, fitting into two categories, and described here to the best of my ability:

1) Tighten head to turn on

A. "Battery-crusher" design, wherein a foam or rubber ring prevents the positive contact of the battery from touching the head circuit board while the light's head is loosened. When the head is tightened, the foam compresses, and the positive, raised contact on the battery eventually makes contact with the head -- which completes the circuit and turns on the light. This design does not usually include a spring in the battery tube, so the battery can rattle if the head is loosened too much. There is also a risk of damaging the battery if the head is over-tightened, thus the colloquial name.

B. "Spring" design (not sure if there is a better name for this), wherein the battery is suspended in the light's battery tube between one or two springs. Differs from "battery-crusher" design in that the battery is always touching the light's positive and negative contacts. The "switch" in this case is actuated when the circuit board contacts the body of the flashlight, again occurring when the head is tightened down. ln this design, the contact board is isolated (insulated) from the rest of the pill, and needs to make contact with the un-anodized ring near the top of battery tube for the circuit to close.

C. "QTC" (Quantum Tunneling Composite) design, wherein a QTC pill is included in the circuit path; when the head is tightened, the QTC pill is thereby compressed. When QTC is compressed, its electrical resistance drops, allowing more current to pass through the circuit and illuminate the LED. This method theoretically allows for infinitely variable brightness between off and max output without the need for advanced circuitry, but in practice some find it "fidgety" and unreliable. In any case, you will generally only find QTC used on custom lights, or from a handful of smaller manufacturers like Peak LED Solutions.

... in all three of these methods, I believe that current needs to pass through the threads at the head of the light to the pill, but there may be exceptions.

2) Loosen the head to turn on

A. The example which comes to mind is the very common Mini-Maglite 2xAA (and Solitaire?) design, wherein a dedicated, spring-loaded switch mechanism OPENS the circuit when the head is tightened down. Loosening the head allows the switch mechanism to expand and close the circuit. I don't know of other lights that work like this besides those offered by Maglite, and I have never had occasion to take one of these switches apart to get a better view of how they work.

I do not claim to be a super-expert... others may know of different twisty light "switch" methods.

Re: Dumb question, but how do the twisty switches really work?

wow, that is great explanation.

quantum tunneling? at first it looked like a joke..

thanks.
wle

Re: Dumb question, but how do the twisty switches really work?

wle said:

wow, that is great explanation.

quantum tunneling? at first it looked like a joke..

thanks.
wle

Click to expand...

You're welcome I think I got the details mostly correct... if not, I'm sure someone will jump in and clarify.

Definitely Google QTC for more info -- it's more complicated than can be explained in a brief paragraph. Or check out Peak LED Solutions' website. As I said, lights using QTC tend to be a specialty item (and relatively expensive), so you probably won't run into one unless you go looking.

Re: Dumb question, but how do the twisty switches really work?

There are other variations on twisty lights:

Liteflux had the LF2X which is off with the head tightened, loosen for mode 1 and further loosen for mode 2. The two modes can be programmed and there are a series of twists to get into other modes (or sets of modes), which I think could also be programmed; if I am remembering correctly. I owned one and I am realizing that I should have kept it. I think there was another model or two that had this same interface (just different battery type(s)).

Nitecore had the EZ series that had two modes; tight and tighter.

Re: Dumb question, but how do the twisty switches really work?

burntoshine said:

There are other variations on twisty lights:
...
Nitecore had the EZ series that had two modes; tight and tighter.

Click to expand...

I'm unfamiliar with Liteflux (though their switch mechanism sounds interesting) ... but yes, two-stage twisties like Nitecore EZ series, Foursevens Atom series (excepting Atom A0), and Thrunite Ti series (prior to TiS) indeed comprise another, separate category of lights that are becoming more common, and better executed, as they evolve. I have an Atom AL and I like the progressive twist UI in a headlamp very much.

Re: Dumb question, but how do the twisty switches really work?

Actually, for completeness, there are other types and variations, yet ... such as variable twisties on the SureFire T1A/Titan, the larger Peaks (NightPatrol, etc), many JB/SWM torches, etc.

Each of these uses somewhat different circuitry design & components for switching and adjusting output.

Re: Dumb question, but how do the twisty switches really work?

ronniepudding said:

There are to my knowledge 4 types of twisty light mechanisms, fitting into two categories, and described here to the best of my ability:

I do not claim to be a super-expert... others may know of different twisty light "switch" methods.

Click to expand...

thanks for sharing,learn a lot.

Re: Dumb question, but how do the twisty switches really work?

This is actually a more informative and enjoyable thread than I thought just from the title.

Actually brought back fond memories of a little UKE 2AAA twisty light I carried as an EDC, most notably on a 12-hour bus ride up to Maine for a wedding.

I think the light 2 different current routes to the driver...one for each mode...So you are stuck with the original driver or else loose the 2 mode turn function