# Trying to remove strobe mode from led (circuit pictures included)



## adamsmh663 (Jun 11, 2012)

Hi guys I have bought an elcheapo led torch from ebay. (also apologies if this is the wrong section/forum, mods please move it)

The thing annoying me about is the modes it has 3 modes Hi/Lo and strobe . I want a simple torch with on/off, but i could live with hi/lo, but absolutely hate strobe.

Anyway here are the circuit pictures so hopefully one of you guys can see what i need to mod to make it a simple on/off torch and remove atleast strobe.


pics:











and a panit drawing if you cant quite make out the details.





the black boxes are like transistors or something they are soldered onto the circuit board (sorry im not expert in electronics) but i do know basics and shoudl be able to do a simple solder.



thanks in advance


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## wquiles (Jun 12, 2012)

What is the picture of the back of the circuit board?

You can also put in a new LED driver - most are between $5-10 from ASIA, and they typically have solderable bridges so that you can change the behavior:
http://flashlightwiki.com/Driver

http://www.candlepowerforums.com/vb/showthread.php?216148-Another-7135-Driver-Wiring-Question

You can just Google for "7135 LED Driver" and should get plenty of links to review, study, etc..

Will


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## adamsmh663 (Jun 15, 2012)

I just removed the resistor? (ID3).

now its working perfect .

simply on/off mode


wooo


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## fireman_steve (Sep 26, 2012)

*how do i remove modes from my torch?*

Hi, I've got a 1300 Lumens CREE XML XM-L T6 LED tourch with 3 modes on, dim and strobe. all i want is on and off (on full) is there any way to pull apart and rewire? or do i need a whole new board?
cheers


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## Gunner12 (Sep 26, 2012)

*Re: how do i remove modes from my torch?*

Which light is this? Usually, you'll need a whole new board. If you are good with electronics and soldering, you might be able to bypass the microcontroller on the driver of the light and turn it into a single mode light.

:welcome:


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## arcman (Apr 10, 2013)

*Possible to mod 5-mode driver to remove flash modes?*

First time here. 

I purchased two Ultrafire XM-l T6 flashlights (Goodbye Maglites!) only to find out that you can't avoid the flashing modes. ( Never in my 60 years have I needed or wanted a flashing mode in a flashlight. I'm amazed that all these lights come with this useless feature )

I ended up buying a 3-mode driver board which was a bit smaller in diameter and I had to machine an adapter to fit. A bit of a pain but all's well with those two.

I'm about to buy a couple more of the same style lights but can't find any with a 3-mode driver that doesn't have some kind of flashing mode. Even a two way would be fine but I can't find that either.

Is there any way to modify the 5-mode driver to defeat the flash modes? Not an electronics guy, but I'm guessing one of the IC's on the board does the switching. You'd think it could be bypassed.

Any hope here?

Thanks.

P.S. Man, the search engine here is a tough one. Sorry, but that verfication thing is BS.


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## rufusbduck (Apr 13, 2013)

*Re: Possible to mod 5-mode driver to remove flash modes?*

You might try linking pins 3-4 with solder. Some Attiny mcu's can be modded this way to give l-m-h only. See the 1.4A driver at Illumination Supply or International Outdoor. It does not work with all 7135 based drivers.


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## MikeAusC (Apr 13, 2013)

*Re: Possible to mod 5-mode driver to remove flash modes?*

There are some Drivers with multiple Groups. Once you've selected the Group you want, you'll never need to worry about unwanted Modes.


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## kosPap (Apr 14, 2013)

*Re: Possible to mod 5-mode driver to remove flash modes?*

what flashlight are we talking about? And what is the diameter of the driver?
There are versions of the 7135-chip drivers that are configurable


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## sidecross (Apr 14, 2013)

*Re: Possible to mod 5-mode driver to remove flash modes?*

Arcman

I am 68 and have used Surefire all my adult working and now retired life and have been now using these new lights mainly the Eagletac G25C2 MKll, Eagletac D25LC2, and the great Nitecore TM26 that have all these hidden modes.

At my age my only need would be for them would be for an emergency location strobe or beacon.

I am just grateful that some of the strobe & beacon modes can be separated from everyday use. :thumbsup:


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## arcman (Apr 19, 2013)

*Re: Possible to mod 5-mode driver to remove flash modes?*

Sorry guys, been away for a few days.

The chip is 20mm diameter.


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## Dr.Jones (Apr 21, 2013)

*Re: Possible to mod 5-mode driver to remove flash modes?*

The modes (all of them) are built into that little 6-pin IC and can't be easily removed or bypassed. What I often do with lights like this is to remove the components of that board and use it as contact plate for a NANJG105C (with custom firmware, so I can have all the modes I want) - supposing there's enough space above the original driver.


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## Edna Shimeluski (Feb 27, 2014)

*How to modify simple mode?*

I have an Ultra-Fire 502B and want to simply modify it to ON HIGH and OFF. I want to eliminate the other modes entirely. I searched here, but can't find any instructions. Any help?


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## Norm (Feb 27, 2014)

*Re: How to modify simple mode?*



Edna Shimeluski said:


> I have an Ultra-Fire 502B and want to simply modify it to ON HIGH and OFF. I want to eliminate the other modes entirely. I searched here, but can't find any instructions. Any help?


A Google search of CPF


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## Mason235 (May 29, 2015)

Hi,
I have brought a torch and it has 3 modes:High,Low and Strobe.The strobe is REALLY annoying.Is there any way that I can get rid of the strobe mode???
thanks,
Mason


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## DrafterDan (Jun 2, 2015)

Why do you folks tag onto a long-dead thread instead of just posting a new one? 

And to answer Mason235's post - we need a lot more information to actually help you. If you look at the first post (from 2012), the requestor posted details and even a drawing. At the very least, please give us the model number of your torch?

The images you posted seem to live on your hard drive. If you would like to post images here, please use an online storage place like Photobucket.


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## Mason235 (Jun 3, 2015)

Sorry,
I got the torch off DX 
It says that it is an UltraFire XML-T6 
Here are the pictures.


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## DrafterDan (Jun 3, 2015)

Hi M,
Thank you for the photo, it helps somewhat. We are more than happy to help, but there are still several questions involved. What battery(ies) does this torch use? That would determine what type of driver to get. My suggestion is to look for a driver (and it looks like this one is 17mm diameter) that does not have a strobe mode. You can see that really there are only a couple wires to unsolder and re-solder on the new driver. Typically, if you see a driver on DX and it says 5-mode, then most often it's got everything including a strobe and the kitchen sink. 

As long as the driver physically fits, can handle the input voltage from your battery or batteries, and can produce enough juice to feed your LED or LEDs, then you're golden. Of course I am over-simplifying it, but this can be a great way to ease into modifying flashlights.

~D


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## Mason235 (Jun 5, 2015)

It takes 1 TrustFire TR18650 2500mAh 3.7v battery


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## Lynx_Arc (Jan 13, 2016)

If you are trying to remove the mode memory which forces you to cycle through the strobe mode(s) even when turned off there is a method of fixing that problem that has to do with taking a pencil and depositing graphite over a capacitor which will bleed off the charge on it that keeps the next mode memorized even when off. I fixed a cheap $3 light and now if I leave it off for about 5 seconds it always starts on high then low so as long as I turn it off after low I never see the strobe mode.


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## Chris_83 (Jan 28, 2017)

I purchases a flashlight with a board very similar to the one in the picture. Note there are three solder tags. 

https://www.dropbox.com/s/a9zu1fmy3vdqvqt/Flashlight Circuit.jpg?dl=0

With my flashlight, soldering the blue negative wire to tag "B" causes the switch to cycle through a different lighting sequence which includes flashing "SOS" in Morse code. 

Soldering the blue negative wire to tag "C" by passes the circuit and the on and off switch just turns on the flashlight to full power without any other options. 

I hope this will be of help to someone.

Kind regards
Chris


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## loneoceans (Feb 3, 2017)

Chris_83 said:


> I purchases a flashlight with a board very similar to the one in the picture. Note there are three solder tags.
> 
> https://www.dropbox.com/s/a9zu1fmy3vdqvqt/Flashlight Circuit.jpg?dl=0
> 
> ...



The circuit is extremely simple, but unfortunately there is no way to remove the 'strobe' mode, and as others have mentioned, it's easier to simply buy a replacement LED Driver board. For example, the one linked by Chris appears to be a 20mm or 17mm driver. 

The 3-pin SOT23 device appears to be an integrated LED PWM driver chip with memory. The 1uF capacitor provides some charge for memory mode, and the other two pins simply act as a switch via an internal transistor to control LED brightness via PWM. Current limiting is provided by the 4 parallel resistors. 

So far I've not been able to find any datasheet for that unknown IC but I'd be really interested if anyone could find more information about it. Otherwise my best guess is that it's a custom mass-produced flashlight IC produced by some chinese fab plant and used in all cheap flashlights


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## Chris_R (Feb 22, 2017)

This is a BIT of a guess, but the only reason I can think they bother with the 1µ capacitor on the YN-20-3 is for timing the relatively slow flash.
They use timing to achieve "low" power, by pulsing the led on/off. (check a phone camera view of it on low - there will be moving bars) .

So you have 

annoying slow pulsing,
useful fast pulsing (dim), and
not pulsing,
(Slow pulsing is "Tactical", supposed to bogey-man scaring and cool, I assume )
If you remove the capacitor , presumably it would be just on, or just off.
If you replaced it with a smaller value you'd get faster pulses. If "slow" which currently is about what, 4Hz(?) were say 100Hz the light would probably just be "dim" .
So change the 1µF to something like 0.022µF = 22nF, or 10nF.
. See what happens!

If you aren't bothered about dim then just bypass the chip and connect power through the parallel resistors. I have 4 x 2R2, so 0.55 Ohms.
I'm playing with a 5W UV led but I get 140mA on Dim and 690mA on full. YMMV.
At 2W the LED gets too hot for my liking.


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