I have noticed the discussion about this, but unfortunately I currently have no plans to produce a dedicated 6V PCB for this. The main reason is that it would add complexity to inventory management.
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What about just selling the MCPCB alone, without soldering a LED or installing into flashlights? Most modders will be able to do it themselves, including soldering a bypass wire around.
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That still means one inventory slot for an item that will never be used in any flashlight.
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But it could be used an may of flashlights that come with a 6V driver option.
And you could potential have only a single MPCB in stock that can be configured by cutting/bridging a jumper/ solder pad
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Of course I’d love for Simon to offer these 6V MCPCB but I don’t think he will. He has expressed in the past the intention to phase out 6V drivers and LEDs in his lights. In a few years I doubt we will have new 6V options.
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I hope by then we have more comparable options to Convoy that will still offer this option.
Not a fan of the FET/linear drivers and Hotrod lights.
And buck-boost converters are more expensive and physically bigger, and less efficient than boost converters.
6V/12V emitters are an easy and elegant way to get a fully regulated driver over the full battery range in a single-cell light.
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Most people even on here are not modders but buyers.
Then there is a big group that can change drivers and LEDs on MCPCB with basic soldering skill and tooling
Then there is a tiny group that is able to solder LEDs onto MCPCBs themselves.
The market wouldn’t be big, it’s not worth the hassle, as he stated.
I agree that it would be nice if, but Simon keeps prices low by ordering and selling a lot of his products and building and making just a few hundred MCPCBs would probably end up in a way higher price than his other MCPCBs
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@ebastler designed a MCPCB specifically with the 73B in mind:
Maybe someone could start a group buy?
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I am also a “regulated driver fanboy”. But the LHP73B is one of the few LEDs that works really well with a one cell buck because of its low Vf even at high currents. A 6V configuration for this LED would be obsolete in my opinion.
What do FET/linear drivers have to do with this?
Convoy released a new 20A buck driver specifically for high-current 3V emitters such as the LHP73B.
And buck-boost converters are more expensive and physically bigger, and less efficient than boost converters.
And buck-boost is a different topology from buck, so the disadvantages of buck-boost compared with boost don’t apply to a 3V emitter running from a single cell through a buck driver.
You can’t run a 3V LED trough a buck driver and get Full regulation over the full battery voltage range.
You get some longer Regulation down to lower voltages from a Linear driver. But of causes at lower efficiency.
So Sure you could uses a Buck Driver with comparable efficiency then a boost driver.
But with the Buck driver and a single cell you wont get the full capacity out of the cell (in a regulated way)
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Look at the runtime graphs of some Convoy lights with buck drivers. Perfect regulation basically to the end.
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Some of them yes, but there are notable counterexamples among throwers. The old batch SFT25R is infamous for having a Vf so high that it fails to draw 8A even on a full battery, and the W5050SQ5 falls out of regulation quite a bit sooner than the new-batch, lower-Vf SFT25R. (Note that under 100% draw without thermal stepdown, the difference in regulated runtime would be more pronounced, and only ~half of the battery’s total energy ends up as regulated output.)
Not that this is particularly relevant to the discussion about discontinuing boost drivers (since multi-die emitters will never out-throw monolithic ones), but I think the existence of these high Vf LEDs should motivate the development of buck-boost combination drivers. Either that or wait for these high-Vf emitters to become obsolete, which could take a long time.
As long as LEDs like SFT70 and XHP70.3 remain irreplaceable, chances are that the production of 6V drivers will continue.
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Yes, the graphs look perfect, but this is not the point. I want my lights to be able to give 100% power bursts even with battery <50% SOC, or even <30%.
Most runtime graphs look like this: Start with full battery at 100% power, then a drop to a lower, thermally stable output level, then stay there. At this lower level the Vf is also lower, so the buck can work easily.
I would like to see graphs with some short 100% output attemts from time to time to see how a light can handle full current at lower SOCs.
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With the upcoming release of the high-CRI LHP73B and LHP531, I believe the SFT70 and XHP70 will also be phased out in the future.
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Only if the luminaire has excellent heat dissipation performance and effectively distributes the single-cell operating current through multiple batteries in series and parallel, can the expected results be achieved.
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This is the second AI scam I’ve encountered this year. The two photos below were provided by an AliExpress buyer; they were taken from the same angle, but the deformation flaws on the flashlight are different. Ah! This is really testing my eyesight and IQ. (For entertainment purposes only)
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Maybe I didn’t make my point clear.
Most graphs take the temperature into account. So far so good.
But the “full-power-abilities” of a driver/light depending on different SOCs is also very important (starting with a cold light every time).
For example: My light has only 30% battery SOC left. I put it out of the pocket, it is cold, is it still possible to get 100% power out of it in this moment? What is the SOC or voltage threshold the (cold) light can’t reach its 100% power anymore?
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That’s not even possible unless ran over with a tank or shot at. Even thin SK68 was quite hard to deform with a hammer. LOL
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Assuming a battery has 30% capacity remaining, its open-circuit voltage is around 3.6 to 3.8 volts. During high-current discharge, the operating voltage drops rapidly; once it falls to about 3.0 volts, the flashlight triggers a low-voltage warning. Because of this, many buyers wonder: “The battery clearly measures 3.8 volts and seems to have plenty of power left, so why does the flashlight trigger the warning so early?” Under low-current discharge, the difference between the operating voltage and open-circuit voltage is much smaller, which is precisely why I recommend using multiple batteries to share the load.
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