NiteCore EX10 Comparison Review

[UnknownVT]

Through the very kind courtesy of 4sevens I have on loan 2 samples of the NiteCore EX10.

Why 2? ....... long story -

Short version -
Preface -
The first sample of the EX10 - seemed every bit as bright as (if not brighter than) the NiteCore Extreme (rated at 190-200 lumens)
(I discussed this in NiteCore Extreme (NEX) Comparison Review).

This led me to start a thread -
NiteCore Lumens Rating where some pretty interesting discussion took place - I found myself scrambling to try to show
(a) there wasn't much difference btween the EX10 and the Extreme - and (b) that a 60 lumens difference ought to be visible, and discernable in photos.

I was also aware of other reviews and reports/measurements that seem to indicate the EX10 was not as bright as the Extreme -
contrary to what I was seeing with my sample.

During my beamshots of this review the first sample of the EX10 would switch Off unexpectedly - obviously a fault -
I think it could be from over-heating as the light was being used on Max - and the light did get noticably warm-hot - hot enough to be noticable - but not too hot to hold.
Leaving the light off for a few minutes (to cool down?) - the EX10 worked again at the same level of brightness.
This fault has only just developed/discovered - I had been using that first sample of the EX10 on Max for plenty of beamshots over the course of at least the last 2 weeks.

So I got hold of another sample of the EX10 from 4sevens - who went out of his way to get it to me - despite of his very tight time schedule (thank you David).

There was quite a difference between the brightness of the second sample of the EX10 and the first one.

Side-by-side comparison beamshots -

Standardized stairway beamshots -

I am reviewing the second (not as bright) sample -
because I feel it is more typical of the EX10 -
I think the first sample (of one) I had is probably an anomoly of being extra bright, plus it was faulty -
(for lots of comparison beamshots of the first brighter sample please see -
NiteCore Lumens Rating )

Comparison Review -

size -

head -

Max brightness level using primary CR123 -

vs. NiteCore Extreme (NEX) also on Max and primary CR123 -

pretty obvious Extreme is brighter than the EX10.

vs. NiteCore D10 on Max - Li-Ion 14500

not surprising from the above comparison that the EX10 is not as bright as the D10 on Li-Ion 14500.

vs. Fenix P2D-Q5 on Turbo/max using primary CR123

hmmmm..... this all seems pretty "negative" since all the lights are brighter in comparison - so what is it similar to?

vs. NiteCore D10 on Max - NiMH

this is more like it - pretty comparable - although there are probably absolute measurable differences - probably in any real-world practical usage there would be very little difference.


OK since the D10 seems to perform so much brighter on Li-Ion (14500) -
is the EX10 on Li-Ion 3.7V rechargeable RCR123 brighter?

vs. NiteCore Extreme (NEX) on Max and primary CR123 (as a control)

nope - the EX10 does not seem any brighter on Li-Ion RCR123 when compared to the Extreme (primary CR123) as a control - this set of beamshots look about the same as the primary CR123 set above.

Obviously I wish the EX10 were as bright as the first sample I had - but that was probably an anomoly - that fact that one also turned out to be faulty probably means it is not typical.

The second sample I reviewed here would, on the surface, seem "disappointing" -
but overall - its form-factor, build quality and even output are very pleasing. It is a very nice flashlight.

Index to follow up parts -

Comparison with more closely rated lights in Post #3

Comparison with first EX10 (#1) on Minimum level - Post #7

Comparison on Minimum level Post #21

 

[THE_dAY]

Interesting.. maybe the first EX10 Cree had a higher Vf than your second sample.

Did you happen to do any runtimes for both the EX10s?

I'm wondering if the first one was brighter due to the Vf or faulty driver?

 

[UnknownVT]

Part 2 -
Comparison with closer lights. -
in the first part I compared the second (more typical?) sample of the EX10 with various lights that the first (brighter) sample was close to.

This was a bit unfair to the second (more typical) sample -
so in this follow up part I picked some lights rated by their respective makers in the 120-135 lumens range to compare with the EX10 rated by NiteCore at 130 lumens -

side-by-side compatison beamshots -

vs. P2D-CE (the original CE with P4 emitter - rated at 135 lumens) on Turbo/max using primary CR123

vs. JETbeam JET-1 MK IBS Max NiMH AA rated at 130 lumens

vs. Fenix L1D-Q5 Turbo/Max NiMH AA rated at 120 lumens

These comparison beamshots seem to show the more typical EX10 is up there among the 130 lumen lights - the JETbeam JET-1 IBS in particular has been found to be a strong/bright light - a kind of "over-achiever"

 

[UnknownVT]

Interesting.. maybe the first EX10 Cree had a higher Vf than your second sample.
I'm wondering if the first one was brighter due to the Vf or faulty driver?

Didn't mean to ignore you.

Sorry, I can't answer that -
hopefully someone who knows more can.

However I always thought a lower Vf normally was brighter?

 

[HKJ]

DHowever I always thought a lower Vf normally was brighter?

Not if your have a perfect current control, then the current will be constant independent of Vf. This means that the power consumption will increase with increasing Vf and efficiency will decrease with increasing Vf.
Due to the way leds are rated the light output will not change with changing Vf.

 

[jbviau]

Vincent, how does the output of your two lights compare on low, i.e. MIN as opposed to MAX? Just curious because I received a second EX10 yesterday, and I could swear its low mode is not quite as low as my first EX10 (which unfortunately I no longer have to compare it to). It's still plenty low, but I notice a difference. Here's an uninformed but intuitive prediction (maybe revealing my ignorance re: electronics): I'll bet the low mode on your brighter EX10 is brighter than the low mode on your other EX10. Would you mind checking?

 

[UnknownVT]

how does the output of your two lights compare on low, i.e. MIN?
I'll bet the low mode on your brighter EX10 is brighter than the low mode on your other EX10. Would you mind checking?

the first (brighter on Max - but faulty) EX10 (#1) is brighter on Min than this EX10 (#2) -
this would stand to reason since the lower levels are achieved by high frequency PWM,
therefore they ought to be in the same ratio of brightness difference too?

 

[jbviau]

That was fast! Thanks. Yes, I definitely see a difference too. Interesting. Guess I got a brighter LED from the bin this time. I'll take your word for it re: how PWM explains all of this unless you or someone else can break it down in simple terms.

 

[UnknownVT]

how PWM explains all of this.

Let me give this a try.

OK, PWM = Pulse-Width Moduation. ( PWM article )

Let's take a very simple example if a light is giving out 100% of light - then using a 50% duty cycle of PWM should in theory give 50% light.

So let's say a light's lowest level is 1/130 - this is basically achieved with a 1/130 duty cycle to make the light appear 1/130th of its original 100% brightness.

Hypothetically if one light was giving out 190 units of light and the second one 130 units of light
it means the ratio between the 2 lights is 190:130.....

Now apply that minimum PWM duty cycle of 1/130 -
1st light = 190/130 units
2nd light = 130/130 units

So the ratio on minimum between the 2 would be (190/130) : (130/130) -
which is still 190:130 ......

 

[jbviau]

Ok, that helped (including the article). Does this mean that the LED in the brighter EX10 is getting more current from the same cell?

 

[UnknownVT]

Does this mean that the LED in the brighter EX10 is getting more current from the same cell?

I don't know, and I don't have means to measure the current to the LED -
but according to HKJ in Post #5 above if the circuit were a perfect constant current source the answer would (obviously) be no.

But I understand that the EX10 is only a boost circuit -
which I think is supposed to be Vf dependent?

 

[42]

Just curious, what is the frequency of the PWM? It must be pretty high since no matter how fast I wave the light in front of my face I don't see the telltale flickering.

Mark

 

[HKJ]

Just curious, what is the frequency of the PWM? It must be pretty high since no matter how fast I wave the light in front of my face I don't see the telltale flickering.
Mark

The NiteCore is not using a slow pwm, but has a very fast frequency:

 

[HKJ]

But I understand that the EX10 is only a boost circuit -
which I think is supposed to be Vf dependent?

A boost circuit can be a constant current source and for led drives it probably is (At least around Vf).

 

[UnknownVT]

A boost circuit can be a constant current source and for led drives it probably is (At least around Vf).

Thank you for that - I did not mean to imply that a boost circuit could not also be constant current regulated.

From my reading elsewhere on CPF - it appears others are saying the EX10 (and D10) uses a simple boost circuit -
and the levels are achieved by PWM, and not current regulation.

If this is correct, would the current to the LED vary if the Vf were different?

Also what would be the likely reasons why the first EX10 was so much brighter - does it have anything at all to do with different Vf (higher or lower)?

Thanks,

 

[HKJ]

Thank you for that - I did not mean to imply that a boost circuit could not also be constant current regulated.

From my reading elsewhere on CPF - it appears others are saying the EX10 (and D10) uses a simple boost circuit -
and the levels are achieved by PWM, and not current regulation.

If this is correct, would the current to the LED vary if the Vf were different?

Also what would be the likely reasons why the first EX10 was so much brighter - does it have anything at all to do with different Vf (higher or lower)?

Event a simple boost circuit can be constant current, but tour need a schematic to tell, or your could disassemble the light and measure it.

The Fenix E01 is a constant voltage boost circuit, where your will see huge variations in light output, depending on Vf.

I do not know what NiteCore uses, and I do not really want to disassemble my two flashlights to analyze it. It is not that difficult to do on the EX10, but I am to lazy today:drunk:.

 

[UnknownVT]

Event a simple boost circuit can be constant current, but tour need a schematic to tell, or your could disassemble the light and measure it.
The Fenix E01 is a constant voltage boost circuit, where your will see huge variations in light output, depending on Vf.

Thank you.

I thought I read the EX10 (D10) were constant voltage boost circuits -
can someone please confirm or deny this?

Thanks,

 

[UnknownVT]

EX10 (D10) were constant voltage boost circuits -
can someone please confirm or deny this?

I just got an e-mail from 4sevens - the EX10 is a voltage regulated circuit
- which probably would explain the difference in brightness (and current) due to differing Vf.

I also asked the question in the thread -
Nitecore EX10 Circuit Discussion

although there was also a reply that said it was constant current -
another of the replies - Post #29

According to koalas findings it is constant voltage

 

[42]

The NiteCore is not using a slow pwm, but has a very fast frequency:

Thanks HKJ. Too bad more light manufacturers don't do this. PWM can get pretty annoying at low frequencies. Very nice graphic, BTW.

Mark

 

[UnknownVT]

I just got an e-mail from 4sevens - the EX10 is a voltage regulated circuit
- which probably would explain the difference in brightness (and current) due to differing Vf.
I also asked the question in the thread -
Nitecore EX10 Circuit Discussion
although there was also a reply that said it was constant current -
another of the replies - Post #29

It appears the jury may still be out on this -
check out the thread -

Nitecore EX10 Circuit Discussion
Posts #31 and #32
Post #33 koala did not say the circuit was constant voltage.....