OSRAM CSLNM1.TG & CULNM1.TG 1mm², CSLPM1.TG & CULPM1.TG 2mm²

Speaking of regulation, it's either regulated or not. So, if the driver is regulated that's what it will do. Linear or buck drivers cannot boost voltage, only reduce it. In the case of linear drivers like the one you linked above (found it here too) or Simon's newer drivers (all of them are dubbed or advertised for SST40, by the way), any excess voltage and current is burned by the driver in its MOSFETs; the driver senses outgoing current in its sense resistor, this happens because when current goes through the resistor it causes a voltage drop in the sense resistor terminals which is amplified by a current sense amplifier (it amplifies the sense voltage at the resistor terminals) and fed into the MCU. The MCU uses this information to precisely adjust the MOSFETs' VGS; this controls the resistance of the MOSFETs to the flow of current, i.e. uses the MOSFETs in linear mode, and this way it can precisely control how much current is flowing (think of electricity like a gas, and imagine the MOSFETs are like a gas valve, and the MCU is someone who opens the valve just enough for the required amount of gas to flow). When less than the maximum allowable current is sensed, the MOSFETs are of course driven “all the way” or in saturation mode (in this case the amount of gas pressure is not enough and the MCU just fully opens the gas valve).

The newest single cell 8A buck driver from Convoy is a very smart choice, because it is a switching driver. This means it does not burn excess voltage (times current which is power) as heat in the board, instead it uses a buck converter to efficiently and precisely adjust the voltage to the led for the required amount of current to flow (sensed with a sense resistor, of course). The reason for such a powerful buck converter in limited space is that it is meant for single cell operation, and thus it is not necessary to employ a much bigger inductor which would be required for it to work with 2S cells input.

If you can swap sense resistors in drivers, adjusting the sense resistor value has a direct effect on the amount of current the driver handles. As an example, Simon's Ø22mm 6A drivers (this or that). They are meant for 6A maximum driving current and employ a 10mΩ sense resistor (R010); this means V = I × R = 6A × 10mΩ = 60mV of sense voltage (in case you are wondering, the current to the emitter entirely goes via the sense resistor). Knowing the sense voltage we can re-calculate the sense resistor value for a different current. Since you'd like to increase current, you could stack another sense resistor atop the one in the driver (more conductance) to raise the current. How much? Well, for +1A let's do the math: R = V / I = 60mV / 1A = 60mΩ; this one was :-D easy. On top of this, I just found an advertisement which precisely sells 2010 imperial 62mΩ sense resistors here, which is super close. Proper driver cooling is recommended if raising its limits, namely if you do away with temperature regulation (removing the onboard NTC). I can understand, though, that modifying a driver requires certain tools and skill.

Back on CULPM1.TG issues, I find somewhat surprising these underperforming CULPM1.TG units. Must be some bad bin. Got them from Shenzhen silver ingot Technology Co., Ltd. in AliExpress?

By the way, the CSLPM1.TG is about less than half the price of the CULPM1.TG, what gives?

I have a thrower with a CSLPM1.TG driven at 6.5A or so, I built it for someone else but needs a repair. Nice to see that I chose a proper driving current for it.

I’m confused too at some point with those tests from Funtastic.

As Barkuti mentioned, surprised to see that the CULPM1 performed worse than the CSLPM1 when the CULPM1 is higher Spec. As in djozz test for CSLPM1 peak at 7.5amp while Funtastic CULPM1 peak at 7amp…

I only tested 6A, 7A, 8A, and 7A saw the best performance. 8A had only 5 lumens more.

djozz did tell me his test was also 7A and that he wasn’t impressed at all.

Yes Funtastic… saw all you posts and tests… Good reference. Thanks…

Thanks for that write up Barkuti, I need to read it a couple more times to understand all of it. I wasn’t familiar with Ohm’s Law so I was scratching my head wondering what the letter “I” meant until I input that formula into google haha.

The CULPM1 leds are from Convoy. I have been using the 7A ramping driver as I’m unsure how good it is to drive them with that 8A driver. There’s no tint shift at 8A so that’s a good sign anyway.

9A max but that’s not what I’m getting on the ones I received from Convoy

I’m starting to feel that Convoy has a badly reflowed batch of CULPM1 chips or these just have a lot difference between each.

4 chips

led 1 - 7A - 1135
led 2 - 7A - 1300
led 3 - 7A - 1250
led 4 - 6.4A - 1320, 7A - 1280

very strange.

Have you described your testing process in detail? If you are trying to get down to that level of precision you should work those details out too.

I’m just using Convoy’s ramping driver

Top three were in the L21A, bottom one in the C8+ , the only difference in the setup is the L21A tail switch. It’s a fet driver so I do understand it’s not going to be the same across all leds but should it be that much? I’ve never had it vary so much on other models using the same springs and batteries

In that case I think there are a bit too many variables to get more than a rough average which I think you succeeded in. Certainly not enough precision to worry about reflow though.

Unless you use a power supply and heavy duty heatsink combined with more consistent measure like bare LED using lux not lumens. This is why djozz and others get so burnt out doing it. That level of detail necessary is a pain in the butt.

Sorry?

What is a FET driver?

As far as I understand, what is considered a (MOS)FET driver is a sort of very simple driver basically consisting of a switch and an MCU. These drivers are unregulated and the only way to obtain modes with them is to use the dreaded PWM (pulse width modulation). To attain regulation the flow of current must be sensed, this is done in a current sense resistor, usually a big sized, ultra-low value resistor in the periphery of the driver board:

A 1206 imperial R005 in this one.

So, technically speaking this is not a “FET” driver. These drivers are regulated, they make use of the voltage they sense via their sense resistor to trigger events in their MCU, that is, they use such information to drive the MOSFET gate so the required amount of current goes through the sense resistor (i.e. they open the switch “just enough”).

Ah, okay. I appreciate the correction. I struggle quite a bit to understand how components work when it’s something new in writing, I learn best visually.

Now I realize that the driver I’m after is one that has stabilization, would that be constant current or something else? What we see usually on boost drivers.

I loved these kind of conversation - it easily grab good information…I actually read up all Barkuti comment and had full understanding…Make sense!

I understand everything apart from the maths haha.

I had a stabilized output in my thinking which is different so now I understand regulation more now

My latest chart on the OSRAM's. If anyone can verify, change, or fill in blanks, please do so.


OSRAM LED’s for max throw

Color - Part # - footprint (LED surface) nickname Max/Pulsed Peak Output (A)

White – KW CSLNM1.TG – 3030 (1mm²) W1 3/3.3A 4.5-5.0 A (W1/NM1)
White – KW CSLPM1.TG – 3030 (2mm²) W2 5/6A 7.0-8.0 A (W2/PM1)

White – KW CULNM1.TG – 4040 (1mm²) W2.1 3.3/4A ~6A (Boost HL)
White – KW CULPM1.TG – 4040 (2mm²) W2.2 6.6/8A 9 A (Boost HX)

Red – KR CSLNM1.23 – 3030 (1mm²) W1

Blue – KB CSLNM1.14 – 3030 (1mm²) W1

Green – KP CSLNM1.F1 – 3030 (1mm²) W1 3/4A 6.5 – 7.0 A
Green – KP CSLPM1.F1 – 3030 (2mm²) W1

Yellow – KY CSLNM1.FY - 3030 (1mm²) W1

More OSRAM Website links

3030 variants

4040 (boost) variants

Clear and simple. Thanks Tom!

Tom E, you may want to fix the nicknames back there: if the NM1 and PM1 are Wn, where n = die area in mm², then the Boost HL and HX which are their bigger footprint counterparts should be dubbed Wn.something, W1+ for the KW CULNM1.TG and W2+ for the KW CULPM1.TG, for example. You could also add some proper, simple surnames to the color variants for the sake of simplicity (just remember that the pure green is the phosphor converted green, with some CRI, despite being listed with a narrow frequency window versus the true green).

Just a suggestion.

It’s a small indutance value of 0.47uH, the smaller the inductance the smaller the DCR usually, which is another reason you want a small inductance value in such small place, to actually minimize DCR at high currents.
Still it is small inductor, low profile, I cannot imagine constant current at 8A, for lower currents like 3A surely no problems. I would like to see a review with a flashlight, without artificial active cooling.
Otherwise it seems to look good for example appears like a couple of external FETs rather than integrated into the switching IC.

Sorry, going with Hank's K1 conventions for nick naming these things - https://intl-outdoor.com/k1-21700-thrower-led-flashlight.html.

Don't think it's the best, but thought Hank was following other conventions.

I'm keeping this is a Word docx file for now. Will make it public when it's more finalized. I've learned a few things since putting this together. The different flavors always had me confused somewhat. For white, looks like the Boost HL and Boost HX are making the old W1 and W2's obsolete, except for the pricing.

Hank's convention seems to be Wm.n, where m is footprint (1 = 3030, 2 = 4040) and n is die size in mm².

Honestly, I still :-) prefer the manufacturer's name; can't go wrong with it.

The 3030 emitters obsolete? I don't think so. As far as I am aware there basically is only one test done of the white flat 1mm² (Reflow conditions tested of Osram KW CSLNM1-KW (White Flat 1mm2)), and even less about the 2mm² (here), both in 3030 footprint.

In all honesty, I find hardly believable that going from 3030 to 4040 footprint can provide much of a performance gain for emitters so small die size wise. And mind you, there are 0 actual tests of the 4040 emitters; just a lot of gossip. A good emitter bin can make a much bigger difference in practice.

In any case let me tell you these are being sold fairly expensive right now, in my opinion of course. And you know why.

Not my cup of tea, in all honesty.