MTN Electronics: LEDs - Batteries - Lights - Chargers - Hosts - Drivers - Components - 1-Stop-US Source

I saw the answer from the other thread.

I think Richards boost driver can do some 5A to 6V emitters and around 2A to the 12V XHP35. Should prove interesting and especially so if/when he adapts them to a ramping firmware. :smiley:

Can’t see much need for 2-3 x the power if it blows an emiteer that peaks output around 2.5A

I actually wonder why he didn’t mention 12V LEDs in his statement. Surely it’s just omitted and not just 6V? Guess we will have to wait and see!

Will it be available with an ATtiny85 option?

Andúril won’t fit on the 25. :wink:

Unknown at this time, brand new and as yet unreleased.

Yes, 6V and 12v.

Lexels are about 6A@6v and 3A@12v. I believe Richards will be about the same. They may be adjusted down a bit to make them more reliable.

I know on Lexels you can adjust the output with a resistor swap if you want to reduce the max output. I assume Richards will be the same.

For instance, with a xhp70.2 you might want 6A@6v, but with a 50.2, that’s too much current. So you would swap the resistor to give you maybe 4.5 to 5 amp at most.

We all just have to be patient.

I wonder if Richard is going to have the driver available for both clickies and e-switches.

These boost drivers will be a hit, assuming they work well. These will offer multi-emitter performance without the work of making a spacer and finding suitable reflectors. I plan to put a sliced XHP70.2 or XHP50.2 in an emisar D1S.

This makes me think of the Sofirn C8F. It’s about the same size and I think the output level and hotspot size will be about the same. Have you considered that light?

I agree, I think the C8F with dedomed XPLs would have similar performance. I did buy the host but have not built it yet since I’m still deciding on the emitters. I have a few lights in this size and output range so I’m trying to think of how to make it a bit different.

But I think the D1S is a special host. It’s very light and compact especially for its reflector size. For a short time I had my 3x3 array of XD16s in the light and and I liked it, but the XD16 array is not reliable yet. So a sliced XHPx0.2 is the next best thing.

Question for you guys:

I currently have a C8 with a XHP50.2 and a RMM FET with 2 18350’s in it. What do you suppose one of these new boost drivers would do to the output of a XHP50.2 when changing over from 18350’s to a single, high drain 18650 (30Q/VCT5) and one of these drivers?

(Obviously these aren’t out yet, so no one knows exact specs. It’s all conjecture at this point)

I did a similar C8 mod a couple months ago. I ordered the parts from Mtn of course, and I asked Richard if I should wait for his boost driver instead (he teased these on his Instagram page last year). He said the 2x18350 with fet would definitely be brighter, since the boost driver will only put out about 3.5 amps at 6 volts, which will be 8-10 amps pulled from the 18650 as the voltage sags.

But as you said, let’s wait and see. At the very least, you’ll get much longer run times, right?

I would guess a lot more runtime and a little bit less peak lumens at turn on if you are comparing turbo.

Good to know. Thanks guys!

I’m guessing at 6v…3-4amps out of a 17mm, 4-5amps from a 20mm and 5-6amps from a 22mm driver.

The 18650 will have more capacity and lower internal resistance.

You just need to replace the springs or bypass them to get the full potential out of the C8. Boost drivers request can pull even higher currents than a FET driver by upping the voltage.

Lowering the resistance at any point in the flashlight itself is crucial.

My thoughts: a quality 18650 would have so much less resistance than 2 18350’s that a FET wouldn’t be pulling nearly as much as a high boost driver. I guess it all depends on what the amps are set at on the boost driver, right?

Yes, but I need to explain myself a bit.

In a single cell light, a boost driver will pull more current as the voltage drops farther and farther from the emitter’s foward voltage to keep it in regulation.

That means using steel springs not bypassed at say 6A current, the voltage drop will be around 0,3V. Which is huge.

Say the output power is 18W for a 6V emitter

Our cell at varying voltages and current draw:

18W= 4,20V x 4,28A

18W = 3,9V x 4,50A

18W = 3,60V x 5,00A

As you can see, current draw increases as voltage decreases.

Now, let’s introduce a steel spring(–0,3V for every voltage)

18W = 3,9V x 4,62A

18W = 3,6V x 5,00A

18W = 3,3V x 5,45A

That means you have to pull even more current out of the cell.

Imagine that but at 50W power! You would be pulling at least 12A at 4,2V, and that could go up to 14A at 3,6V, or even 15A at 3,3V! With only a steel spring and no bypass, that would be go much worse. And that is not even counting the internal resistance of the cell, and other resistance in the circuit.

You’d probably get either a low voltage warning almost instantly due to the huge spring resistance, a burned spring, or a huge power loss.

That problem is still there with a FET driver, but since current pulled goes down with voltage, it isn’t as much trouble.

TLDR: For such a powerful boost driver, going with a single 18650 is crucial for both energy and power density. You also need to get rid of all almost all contact resistance, which includes the springs.

Edit: Remove something I should not have said :person_facepalming:

We get it we all bought your springs Mr BlueSpringM :slight_smile:

I have a BLF D80 that has been waiting for a decent driver for a XHP50.2 build. can’t wait!