Fenix P1 two stage mod (here it is)!

Long awaited - here it is, but that was a lot of hard work.
Everybody is warned if he wants to try the challenge!

No warranty at all!

Here is the whole story: fenix_p1_two_stage_mod.htm

jugeh

nice. I could do w/o the 2.5mm gap between the head and body, but overall, good idea.

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I haven't personally seen a P1, but couldn't you just use a FireFly 2-stage switch?

-DF

good work, but it`s a bit to thick for practical use.

what we need is to surface resistor mounted on a very thin double side pcb and use an switch the all metal type used in cheap mice.

the sprung leaf type soldered in place on the pcb, so that when you screw the head down, it switches in the resistor for the low power mode.

all we need now is somebody to make it.

regards.

DF: I have never seen this switch. Is it a twisty with electronics?

TinderBox: It will be very hard to get a thinner design. Surface mounted resistors as needed are 2.2 mm thick. That's just 0.3 mm difference. AFAIK this kind of switch is for very low currents only.

very nice, i want to mod mine :rock:

you are might be right but have a look at the switches in this thread.

the original LaCrosse BC-900 switches.

very low profile.

https://www.candlepowerforums.com/threads/124016

regards.

This is looking down the bore of my CR123 brass FFII body.



The battery (negative) first touches the contact bar on the right which has a resistor inline causing low output. Tightening the head further causes the battery to contact the button head screw which is in direct contact with the body causing high or full output.

-DF

jugeh said:

Long awaited - here it is, but that was a lot of hard work.
Everybody is warned if he wants to try the challenge!

No warranty at all!

Here is the whole story: fenix_p1_two_stage_mod.htm

jugeh

Click to expand...

Your comment about shorting li-ions being dangerous is very true.
I would be VERY careful especially in a sealed P1. Scareeee!!

Cool post, thanks.

It's time for an update!

Why? Because the risk of short-circuiting with the first solution was too big and the design was not flat enough.

So here is my second prototype:


This one drops into the bottom of the Battery-tube (the "cold" side without any risk of short-circuiting).
The PCP is a doublesided 0.5mm thin, diameter is 17mm (like CR123A). The backside has to be connected to the inner ring on the topside. The center hole must be smaller than the pole in the battery-tube (< 6 mm). The resistors are SMD type 1206. I choosed 3 x 47 Ohms in parallel that gives 15.67 Ohms and 0.375 watt.
If you plan to use rechargables I would take at least 4 x 68 Ohms in parallel that gives 17 Ohms and 0.5 Watt. The resistors are also 0.5mm thin so the complete drop-in-switch is about 1mm.

jugeh

Way to keep on keepin on jugeh, that takes some serious patience. Any plans of mass making these things? :naughty:

Awesome. I need (3) of them please.

looks great! I'll take one too...

As obviously can be seen it is really handmade just with file and knive. I don't have any tools for mass production. But I'm quite shure there will be a CPF'ler able and willing to take this task. Nevertheless I'm open to help with ideas and advice (if needed).

jugeh

Agreed, someone just needs to produce it now. I'm pretty sure the feeler thread can be skipped for this project.

jugeh - Great idea! Why does the center hole have to be smaller than the raised contact at the bottom of the battery tube?

Because it has to make contact to the backside of the PCB. The bottom of the battery tube is also HAIII except the raised contact. The hole may be bigger if you can remove the HAIII on the bottom. But then it is no longer just a drop-in whithout changes on the light itself.

jugeh

So how does this get taken to the next step, are there any likely canidates to make it? I would try it myself but I would probably end up with a burnt luxeon emmiter stuck in my wall. :huh:

Boy - I'd go for a couple of these if anyone would produce them!!!!

I don't really understand how it works and how it is laid out. Would anyone take the time to spell it out for me?

thanks, John