Tuesday, December 15, 2015

Quickie #5: Inside of the Fenix LD12 tail switch

The Fenix LD12 is quite powerful (125Lm) and small size (powered a single AA cell); the flashlight is quite tough with it aluminum body but it has two weaknesses : the rubber capped buttons.
Although i found a way to protect the side switch, i still didn't found any good way to protect the tail one.

But... Before trying to protect it, what's inside?

Let's open it
From Left to right :
  • A Circlip, that holds firmly the switch into place AND make contact to close the circuit between the switch and the flashlight body.
  • The switch (with click and momentary ON features.
  • A washer that press on the rubber cap to keep everything sealed and waterproof
  • The rubber cap
  • The tail body
  • The whole Tail switch

The switch
A closer look

Here we have a simple two sided and circular PCB, with a mechanical switch on one side, and a spring on the other one.
To pass through the PCB, a simple tin droplet in a hole makes contact between both sides :

The spring is held by three tin droplets that pass trough the PCB to connect the switch races.
The switch features both ON/OFF by full click and momentary ON by pressing gently on it.

Fenix went far in making the rubber cap: they even added their brand logo:

Note that this rubber cap is dead already:
I would have liked a lot if Fenix had supplied spare rubber caps with the flashlight...

What's next?
Planning to make a remote switch
As i have two tail bodies, (and everything twice, only the rubber cap has no working twin here), i am planning to make a remote pressure switch based on what Fenix made for their bigger products :