Review: Ultrafire M51 (MT-G2 P0) and mod

Thanks.
I actually don`t want to have too many pictures in my reviews.
Some have soo many pictures, that I don`t even read the text.. it just looks like a catalogue.. buy it, be happy kind of thing.

So I add some pics in the end, and I link to many pictures, or have mouse overs and such..

I don`t need to see 5 pictures from different angels of the bezel.

5 pictures of the lanyard

5 pictures of the holster

etc..

but that`s just my taste ;)

feel free to comment about reviews in general in this thread :D https://budgetlightforum.com/t/-/20189

I don’t know about the others but I personally prefer a lot of pictures. :smiley: And I see you did have a lot of explanations, dimension measurements and runtime graph too, it’s full with info. :slight_smile:

By the way, did you try to shine this light in lower modes on a spinning fan and could you notice PWM patterns?

I just took a picture, exposure of 1 second.. and I can`t see any PWM.

The following is from 2 lights, that use PWM. also 1sec exposure (although a little better focused)

definitely above normal ultrafire or xxxfire quality!

is that what you wrote? hehe

Nice review. Great pictures.

Gotta agree with others. Too expensive.

That’s one heckuva good looking light
But $120+ ?? For an Ultrafire??

I’ve got the K40M and it cost less than this :frowning:

I see what you did there.

Decent light for 70$ max, for more they can keep it :slight_smile:

Great review anyway….

Ok.. I need some help:

In my 2nd post, you can see that changing the wires to 18AWG didnt improve the output much..

So I want to do a resister mod!

THis is the pic with the current smd resistors.

1. Can this be resistor modded?

Stock I got 7.6V and 3.07A to the LED.

According to the picture below, the R240 would be 0.240 ohm,

so I used this website: and 4 times 0.240 ohm makes it 0.0600 ohm.

2. Is this correct?

3. Using THIS website, I calculated that 7.6V and 3A equals 22.8W
is that also correct?

4. but the same calculator shows 2.53 ohms....

where did I go wrong?

Ok, I got some info about calculating the A from the LD29 mod thread


So I will just enter my own values, and see if it makes any sense.

Quoted from the mentioned thread.

The ouput amps to the LED is 3A, so therefor the sensing voltage is V = I x R = 3 x 0.06 = 0.18V. The sensing voltage will stay constant, so if you want 5A output to the LED, your sensing resistor should be: R = V/I = 0.18/5 = 0.036 Ω. So your best bet would be to Remove the 4 SMD resitors, and put a R036???? resistor. Unfortunately, it is not always possible to get the exact resistor in small quantities. Thus we stack resistors to get to the desired overall resistance.

I can`t follow the following numbers yet.. I tried, and think its correct... but please let me know if I do something wrong.

- 2 x 0.1Ω in parallel = 0.05Ω, put that in parallel to the original 0.06Ω = 0.0273Ω = 6.5A?? correct? (0.18/0.273)
- 3 x 0.1Ω in parallel = 0.03333Ω, put that in parallel to the original 0.06Ω = 0.0349Ω = 5.15A?? (0.18/0.0349)
- 4 x 0.1Ω in parallel = 0.02500Ω, put that in parallel to the original 0.06Ω = 0.0484Ω = 3.71A?? (0.18/0.0484)


Forget all the math, there's no way to know if it's correct from one light to another until after you change the resistors and see how much difference it makes. Just stack one resistor at a time, something reasonable that won't whack it too hard in one go, like 1/2 ohm (R500). The higher your added resistors are, the less increase each one will give. Adding a really low one like a R020 could be too much, using a bunch of higher value ones gives you a lot more control and won't suddenly do something bad on you.

Bookmark this page, it'll decode anything: http://www.hobby-hour.com/electronics/smdcalc.php

Thanks..

I have this pack from fasttech. But none of them have the R in front of the numbers, so I guess they are really big.

and thanks for the link. I also just found that one during my search.

edit; just checking my SMDs, but all are really really big.. strange because it shouldnt be , looking at the details at fasttech.

Dude, you live in Tokyo. There are probably thirty SMD resistor vending machines within a half mile of you right now. :D

No, we only have vending machines for flowers, birds andbatteries, and I think I`ve even seen one for drinks and cigarettes.

https://www.fasttech.com/p/1234412

Click the drop-down box for other values. They have a not too bad selection, though only in 0805 size.

oh, that`s 0.5 ohm? Mmm, again the smallest I have seems like around 10ohm

Yep, that's the giant assorted pack of uselessness. :P

You now are part of the "we did that too" club. :D

Great!.. not

someone mentioned this to me, and I just bought it... left it somewhere in my closest, took it out a few hours ago.. and now realized its not any better than the spoon I just used.

edit: I found the crook here

Naughty, naughty, Pulsar13! :p