Switches for high currents

Flashlight Modding and DIY Parts
1

So.. I'm looking for switches with PCB that can handle up to 8A for short periods.. normal flashlight size (20mm or smaller) like used in the UF 504 host, UF980L, L2P and so on.

Any hint? :)

2

Get normal clicky and then copper contact mod

I saw it somewhere :nerd_face:

3

That’s a lot of amps how about using a regular switch with a relay or maybe a switch from a DRY.

4

And how about normal switch with FET drive ?

5

This is a VanIsleDSM FETtie up to 12Amps for L2(x) and Surefire 6p 9p

6

Where did you get that switch?

7

45$ is a little heavy..^^

Are there any cheaper FET switches? Where could I find the DRY switch?

8

FET switches can made easily. problem is you need to get both -/+ to circuit. most flashlights just on/off negative wire.

if you can get a wire from positive (+) of battery, you can create it yourself easily.

FET switch that lieber post here has 3V coin cell inside it. that way you don’t need positive supply.

9

I got it from Jesse himself, Canada. It was over 50€ incl. shipping.
Running the manafont xm-l t6 dropin there was an obvious perceptible increase in lumens output (approx. 25%), but for me not worth that price, so i sold it after trying out. Anyways, my manafont dropin goes direct drive on hi, if i’m not mistaken. How could be 6.7 Amps tailcap-reading be interpreted?

10

My DRY and TR-J12 switch wrote
“1.5A 250V”
“PBS-101”
“OMTEN”
.
Same these switches
http://www.manafont.com/product_info.php/uniquefire-replacemnet-tailcap-switch-component-5pcsset-p-8597
http://www.manafont.com/product_info.php/flashlight-replacement-accessories-for-trustfire-x6-sst90-74mm-lens-tailcap-switch-orings-p-8927
.
.
.
But this wrote
“1.5A 250V”
“KAN-28”
http://www.manafont.com/product_info.php/ultrafire-replacemnet-tailcap-switch-component-5pcsset-p-7451
.
.
.
All link above I have them all.
May be This can help :wink:

11

I can confirm that the last switch Pok linked to is the same switch that is used in the HD-2010 with a larger board mounted on it.

12

I always wondered how the NiteIze IQ switch does that trick. Where does it get it’s positive voltage? Coin cell?

13

Is the Niteize a Fet switch? Would it be able to handle higher currents? If so I'll get one and take it apart. :D

14

Its an electronic switch, so probably a FET switch - although I doubt it is supposed to handle 5A. But how does it work in principle? The same principle could be applied to a bigger FET then.

15

I'll pick one up next weekend and take it apart. Anyone have any new suggestions for high current switches. The one in my X6 died.

Edit: Forgot to say this needs to be able to handle around 12 amps of current.

16

I use CR2016 cells in some of my PT54 lights namely 501 lifepo4 & TR1200 AF NiMH (18650size) x 3 for my tape switches. On my PT121 green 4d mag was able to skip the coin cell and power off existing 4Ds.
All of the are positive ground lights. BTW all are FET

17

My knowledge of electrical engineering is very rudimenary. In case of a 3V coin cell, only the g (Gate) of the FET will be exerted? FETs are quiet cheap, but which one would fit our requirements? For example http://www.conrad.de/ce/de/FastSearch.html?search=FET&initial=true

I modified your diagram, is this basically correct?

18

Your edited circuit could work if the ground of the battery is at the same potential as the ground of the light, or else you’ll just be slowly draining the coin cell.

With a coin cell, the top wire of the switch connects to the positive off the coin cell instead of the top rail and the ground of the cell is the same ground as the rest of the light. The resistor is to limit the current from the battery and maybe you can even eliminate the resistor altogether so very little current is drawn from the battery for a longer runtime with the switch.

Lol, switch can also have runtimes now.

19

Likely not helpful for the OP, but still germane to the subject and something I would like to try in a 7135 driver light;

Hardwire the + & - to LED and 7135 chips, and run only the 7135 enable pin through the switch (also to power a uP if used) Switch and driver would need to be integrated (no tailcap switch), but no current through the switch here. The other question I don’t have an answer is if there would be any parasitic drain when the 7135 enable is off.

Ok, go easy on this beginner & thanks for all the help here.

Edit: guess that wouldn’t work if the enable was used for PWM.

20

These ratings are usually for AC, and if using DC (we are) the rating should be reduced by a factor of ten.

This becomes 1.5A at 25V, or around 9A at 4.2V.