Luminus SFT40 test

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Tom E
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thefreeman wrote:
Tom E wrote:

Well, nothing that simple to the driver itself. Theoretically you could find a lower performing FET but that has other risks.

I'm cautious about downgrading springs. In lowering the amps to 8 or 9 for example, that's still a lot of amps for cheap springs and I'd be concerned about melting them, as I've seen/done before.

Wow melting ? Shocked was it quite thin ? I mentionned this thinking about the one in the H600 IV, 0.8mm, steel and quite long, about 50mΩ, it gets quite hot (the light draws 6A which a nearly empty cell) . I was thinking shorter and thicker steel spring would do if that exists (because 50 mΩ would be too much). For lengthening wires, AWG22 is 0.53mΩ/cm, 24 is 0.84mΩ/cm, depending on the resistance needed it could get quite long. I should add the SFT-40 in my DD calculator ( https://www.geogebra.org/graphing/raa8dkdm ) since it has a lower Vf than the SST-40, it helps see the effect of added resistance (but without knowing the current it’s difficult to estimate the light’s resistance)

Sorry, melting meaning burning off the coating, deforming the steel. I've seen them collapse then breaks the connection because of the contraction. All depends on the quality and it's rare we can get specs on springs.

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[FLF] Five Light Friday https://budgetlightforum.com/node/78749

Check out some of my new lights (picture heavy) and quick first impressions of them here: https://budgetlightforum.com/node/77180

My Sft40 beamshots / comparison thread: https://budgetlightforum.com/node/78100

The BLF GT with SFT40 (2300lm, 2700m+ @ 30 seconds!)
https://budgetlightforum.com/node/79561

Ryley
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ArtieT59 wrote:

ea01 moded w sft40 beamshot Smile


 


https://budgetlightforum.com/comment/1792569#comment-1792569


 


 

What battery did you use in your EA01? I also swap my SST-40 EA01 with SFT-40, with new and fresh charge gold Vapcell 21700 the emitter got burn after a few times on turbo mode… black dot in the phosphor Facepalm

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JaredM wrote:
Got it. 9.5A is ideal IMO. …

I'm going to try and resistor mod Simon's ramping driver to 9.5A and see if it in fact uses a TINY13A and customize a UI.

Emitter peaked at ≈10.2A in djozz's test. Not all emitters perform the same, and even if the differences are small with just one test we don't know where this one is at.

Setting the limit at 8.8A (in Convoy's ramping driver) is easy, just stick an R050 over the R005 sense resistor. With an R025, or two R050's in parallel over the stock R005, limit raises to 9.6A. Personally, I would stick an additional R050… or not care at all (whereas 10.2A is ≈2630 lemons, 8A is ≈2450, which is 93.156% of maximum output anyway).

Concerning the driver, at this point this regulated linear driver is my favourite, namely due to certain performance hindering shenanigans happened to the other “SST40” linear drivers at Convoy. Hardware wise it is the best one in every respect, although the stock firmware is somewhat limited and may not be everyone's liking.

If someone's going to develop a more common software for the MCU, I would be pleased. Also, porting some firmware from Toykeeper should be easy. Question 

 

Regards everyone

P.S.: This emitter in CRI95+ would be a blessing.

Wed, 08/11/2021 - 11:23

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ArtieT59
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Ryley wrote:
ArtieT59 wrote:

ea01 moded w sft40 beamshot Smile

 

https://budgetlightforum.com/comment/1792569#comment-1792569

 

 

What battery did you use in your EA01? I also swap my SST-40 EA01 with SFT-40, with new and fresh charge gold Vapcell 21700 the emitter got burn after a few times on turbo mode... black dot in the phosphor :FACEPALM:

 

I used a 9amp 1100mah Epoch 18350. everything was fine

 

but i was using a Lishen 21700 9.6amp 5000mah, and i got ANGRY BLUE led when fully charged. it was very bad, so i immediately set max stepped ramp to 120/150 and did not go into turbo on a fully charged 21700. once the 21700 voltage had dropped to under 4volts, going into turbo was fine. 

 

But i had the idea of using this less powerful 18350 the other day and i feel like it is much safer. I have not had angry blue since that first day. 

 

I just make a point to make changes Right Away to UI or whatever i can when i see that angry blue happening, becasue that black dot in phospher can happen quick!.

[FLF] Five Light Friday https://budgetlightforum.com/node/78749

Check out some of my new lights (picture heavy) and quick first impressions of them here: https://budgetlightforum.com/node/77180

My Sft40 beamshots / comparison thread: https://budgetlightforum.com/node/78100

The BLF GT with SFT40 (2300lm, 2700m+ @ 30 seconds!)
https://budgetlightforum.com/node/79561

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Gents, I need some advice. Seems I ordered the SFT-40 on a 20mm MCPCB. Not sure what that was for, thought I’d get the bare LED. So, is it advisable to use this part in an SST-40 Astrolux FT03? What else must or can be done? I measured about 6A with a 26650 that I ordered with this light. Surely it would be more fun with more amps.

Thoughts?

Spitzbube.

Tom E
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6 amps is a bit low, dunno maybe the cell. But the SFT-40 has a lower Vf so if you got 6 amps on a SST-40, you should get about 7 amps on the SFT-40 in a FT03, but of course you can do better than that - spring bypasses would be the first thing I'd do. Think the FT03 uses a bigger MCPCB? If so, you'll have to see if the 20 mm will allow wire clearance, and if you want it secured down, maybe drill and tap screws.

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Yes, thanks. I guess if it doesn’t fit, I’ll swap LEDs. Measured the double springs and had very low resistance, but I guess my meter is not good at measuring it. Will bypass it.

Edit: Color is very neutral. Nice.

Spitzbube.

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Sub ohm can’t be measured with a common DMM, you need to pass a known current through the spring and measure the voltage drop.

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Unheard wrote:
Yes, thanks. I guess if it doesn't fit, I'll swap LEDs. Measured the double springs and had very low resistance, but I guess my meter is not good at measuring it. Will bypass it. Edit: Color is very neutral. Nice.

the ft03 has a 28mm board, it is possible to create clearance with 20mm board if needed but requires sketchy centering ring stacking. 20mm by itself does not clear the reflector bottom. I would 100% reflow the sft40 onto the original sst40 mcpcb from the ft03. Should have no problem with that. 

[FLF] Five Light Friday https://budgetlightforum.com/node/78749

Check out some of my new lights (picture heavy) and quick first impressions of them here: https://budgetlightforum.com/node/77180

My Sft40 beamshots / comparison thread: https://budgetlightforum.com/node/78100

The BLF GT with SFT40 (2300lm, 2700m+ @ 30 seconds!)
https://budgetlightforum.com/node/79561

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Yes Artie, it’s easy but the LED suffers. For now, the board found its home in a Sofirn SP33V3 that I had no use for. Maybe I’ll reflow it later or buy some new LEDs.

Spitzbube.

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This 8A “12-groups/biscuit” buck driver at Convoy (marketed for the Osram KW CULPM1.TG or White Flat 4040 2mm²) is also suitable for high powering this SFT40 led (better than for the CULPM1.TG, imho). It's pricey, though.

I'd prefer a universal, high efficiency regulated high power boost-buck driver. A regulated boost-buck driver always ensures the full drive current independently of battery voltage or state of charge (for as long as the input voltage is above the minimum, that is). This way you wouldn't need to care about angry blue overdriven emitters, or always fully charged batteries to get maximum performance. But well…

Please avoid fully quoting lenghty posts, namely with nested quotes. Trim quotes down to the essential. Helps with neatness and legibility. Thanks.

The human mind, and its programming, is at the forefront of a particular battle of The Light vs evil dark forces. Nearly every human being on this beautiful planet “Earth” has some sort of negative mind programming in its mind. And you better take care of your mind programming, or someone else will in this wicked world.

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DTales wrote:
Thank you for the test, looks to be well made by Luminus. I have one on order, will try it in an L21A. Sweet spot around 8 Amps?

 

Does Simon will offer L21A with SFT 40..

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This host goes very well with the SFT40. Host L80, Mantaray driver with a stacked R020 resistance and 20AWG cables, 2 20AWG derivations. With the amperimeter clamp I measure 11A and according to my measurements (which can be a bit high) 2620lm and 670,000cd

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What’s the reflector inner diameter and bezel outer diameter on that L80?

Nice numbers anyway

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Bezel 76mm, Reflector I think 69.5mm x 55mm depth

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Pacolux wrote:
This host goes very well with the SFT40. Host L80, Mantaray driver with a stacked R020 resistance and 20AWG cables, 2 20AWG derivations. With the amperimeter clamp I measure 11A and according to my measurements (which can be a bit high) 2620lm and 670,000cd…

Mantaray driver with a stacked R020 resistance? What I can remember from having seen it in AliExpress somewhere, the Mantaray driver you are speaking of uses an R015 sense resistance, and claims up to 7A of output. With these figures it is easy to infer that maximum sense voltage is Vsense = Istock × Rsense = 7A × 15mΩ = 105mV.

Technically speaking it is a linear driver or regulated variable load driver. Uses a MOSFET or MOSFETs as variable resistors, and a sense stage to “feel” the flow of current and do its job.

These drivers are set for a particular current. When current goes through them, they sense it in their MCU thanks to its sense resistor and operational amplifier. This allows them to regulate in a sort of conscious way.

The key with these is to adjust the sense resistor value properly, if required. When you change the value of the sense resistor in the driver, you can obtain the new maximum current value by using Ohm's Law. Also, additional sense resistors in parallel add current to the limit. The limit for the stock driver is I = Vsense / Rstock = 105mV / 15mΩ = 7A, this is explained above when calculating the maximum sense voltage. Now, with an R020 in parallel with the stock R015, we have to add: I = Vsense / R020 = 105mV / 20mΩ = 5.25A. All of this being said, Pacolux's Mantaray driver with both an R015 and an R020 in parallel as sense resistors will now allow up to 7A + 5.25A = 12.25A to the emitter before using their MOSFETs to throttle the output and protect the emitter from overcurrent in doing so.

All of this being said, Pacolux is overcooking its SFT40 emitter. I think 7A is plenty for this emitter. If you really need to add something using this driver, I'd use an R100 for 1.05A extra, 8.05A total. This is toast enough. Please consider that not all emitters behave exactly the same, and that one must be sure that the driver fully meets the claimed specifications, because if not final maximum current figures can be different. To illustrate this I was recently setting up a custom S21A with SST-20, using a Convoy 12-groups driver I received months ago as replacement for a recalled defective unit: presuming 60mV sense and R020 plus R050 sense resistors in parallel the unit should have attained 4.2A, but I finally got 4.7A (variations in sense resistor values also matter). Check this here, among other things related to obtaining correct measurements with these driver types when using power supplies.

Please avoid fully quoting lenghty posts, namely with nested quotes. Trim quotes down to the essential. Helps with neatness and legibility. Thanks.

The human mind, and its programming, is at the forefront of a particular battle of The Light vs evil dark forces. Nearly every human being on this beautiful planet “Earth” has some sort of negative mind programming in its mind. And you better take care of your mind programming, or someone else will in this wicked world.

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Pacolux wrote:
This host goes very well with the SFT40. Host L80, Mantaray driver with a stacked R020 resistance and 20AWG cables, 2 20AWG derivations. With the amperimeter clamp I measure 11A and according to my measurements (which can be a bit high) 2620lm and 670,000cd ![url=https://ibb.co/mz0VzRq][img]https://i.ibb.co/ZTSpTf8/20210812-110955.jpg...!

Does your L80 have a donut hole with a domeless Led? Tried mine with Culpm1, Cslpm1, Cslnm1, also dedomed Xhp50.2. The results for all of them = donut hole :’

Pacolux
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PeyoX wrote:

Does your L80 have a donut hole with a domeless Led? Tried mine with Culpm1, Cslpm1, Cslnm1, also dedomed Xhp50.2. The results for all of them = donut hole :’


With the original SST70 I had a donut hole visible to several meters, with this SFT40 has nothing and no rings in the crown
Pacolux
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in English is corona or crown?

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Pacolux wrote:
in English is corona or crown?

Corona Thumbs Up

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Pacolux
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Exactly, I’m talking about that aliexpress driver with a detection resistance R015.
I like that my LEDs work hard, maybe 8A is enough but I can see a difference of almost 400lm between this Pioneman and a Mantaray host C8.2 with Driver 8A by Simon and SFT40. Actually with the Stock Mantaray driver I can not read more than 6.6a on the clamp as with the 8A driver for Simon Culpm1 I can not read more than 7.6 with my AMperimetric clamp UNI-T UT210E.
I also did tests by downloading a bit the battery to verify that the LED was not saturated, with the battery at 4.15V 9,3A it and about 100lm less than with the battery fully charged and 10.8A

PeyoX
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Pacolux wrote:
With the original SST70 I had a donut hole visible to several meters, with this SFT40 has nothing and no rings in the crown

I just realize that you get a perfect reflector, Kinda jealous though :’

This is mine:

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those details should not harm anything

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Pacolux wrote:
Exactly, I'm talking about that aliexpress driver with a detection resistance R015.

Sensing resistance is the more appropiate term, detection and sensing do have different semantics. By the way, are you using DeepL to help you with this? Wink 

Concerning these matters, every time you mention some important part it is important to post a link with specifications. This is very helpful, namely for people who have never heard something about it.

Pacolux wrote:

I like that my LEDs work hard, maybe 8A is enough but I can see a difference of almost 400lm between this Pioneman and a Mantaray host C8.2 with Driver 8A by Simon and SFT40. Actually with the Stock Mantaray driver I can not read more than 6.6a on the clamp as with the 8A driver for Simon Culpm1 I can not read more than 7.6 with my AMperimetric clamp UNI-T UT210E.

¡Buf! Facepalm 

What is this Pioneman?

Mantaray host C8.2, had seen it before. Apparently a great C8 type host with 26650 tubing. Can't say anything else about it.

So you tell me that you are using the not very correctly marketed 8A driver for KW CULPM1.TG with the Mantaray C8.2. 0K.

Do you know that such driver is a switching buck driver? I guess when Simon ordered this 8A driver, due to the high current output the driver manufacturer decided to use a switching topology to minimize heat dissipation, increase efficiency and etc. This is nice.

However, since it is a switching driver, as a rule measuring the current at the tailcap or using a clamp meter to measure the current will not give you the current at the emitter. Because of it being a buck driver, it only pulls what it needs from the battery.

As an example, let's say the Vf of your SFT40 is ≈3.4V at 8A, this is 27.2W at the emitter. For the switching driver to be able to deliver this, it needs this amount of power divided by its efficiency at max or in high for this to be possible, let's say 27.2W / 0.88 = 30.90̅9̅W at the input presuming 88% efficiency in these conditions. With a fully charged battery and optimized current paths, the driver may be receiving ≈4.1V at the input, and so it would only pull ≈7.54A in these conditions. If you slightly discharge the battery, you will be able to measure more current with the clamp meter. If you continue discharging the battery the measured current with the clamp will at some point top out and then start going down, because eventually the driver will not receive enough input voltage for it to be able to deliver enough voltage to the emitter for it to receive 8A…

Addendum moral: with switching drivers you can't use the “tailcap current” or clamp current as a measure of what the emitter is receiving. This is incorrect. Period.

I am fairly sure that this buck driver delivers 8A at the emitter for as long as it receives enough input voltage, or this is what should happen according to its architecture.

And sorry, but I'm not going to continue with this. You need to understand how the different drivers you are using actually work, how the flashlight internals behave, and etc.

Something I've for example done in the past, and a very wise thing to do, is to buy a pair of these drivers as test devices for a proper review, submitting them to HKJ, a professional tester and the owner of lygte-info.dk. It's all I'm going to say. ¯\_(ツ)_/¯

Have a nice day.

Wed, 08/25/2021 - 23:13

Please avoid fully quoting lenghty posts, namely with nested quotes. Trim quotes down to the essential. Helps with neatness and legibility. Thanks.

The human mind, and its programming, is at the forefront of a particular battle of The Light vs evil dark forces. Nearly every human being on this beautiful planet “Earth” has some sort of negative mind programming in its mind. And you better take care of your mind programming, or someone else will in this wicked world.

Pacolux
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I do not understand how the electronics work, my modifications are based on trial and error. I have broken more flashlights than I have been successful. I’m sorry if I don’t understand much but languages ​​are not my thing … anyway I try to learn by reading forum members like you

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By the way Pacolux, what is the value of the sense resistor in the 8A driver for KW CULPM1.TG?

 

 

The sense resistor is the lowest value, biggest size resistor onboard, and is in series with the driver's output (with the emitter). This is something you may already know. In the above picture, right next to the negative or black wire. It is an R0-something, but what is that something?

Just curious. Given its switching nature, I'd like to know how good is the sense resistor stage in such driver.

Please avoid fully quoting lenghty posts, namely with nested quotes. Trim quotes down to the essential. Helps with neatness and legibility. Thanks.

The human mind, and its programming, is at the forefront of a particular battle of The Light vs evil dark forces. Nearly every human being on this beautiful planet “Earth” has some sort of negative mind programming in its mind. And you better take care of your mind programming, or someone else will in this wicked world.

Pacolux
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R010. Will this driver turn up the current by stacking resistors? I say it because for example in this Convoy driver6V 9,75 | Controlador XHP70.2 para una celda it does not

Pacolux
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stacking resistors = additional sense resistors in parallel, it is understood?

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People always talk about sense resistors, this should imply that a voltage is measured over the resistor and a feedback-loop is in place which makes the current constant. But in many drivers a fat low-value resistor in series with the output is talked about as sense resistor but it is not sensing anything, it is simply a dumb current limiter, and if nothing else happens in the driver, the current will go down with the voltage of the battery.

Not sure which one is the case in this driver.

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