Lumintop GT4

I don’t recall seeing anything bad about the R90C either. I own one and it’s awesome, puts a huge smile on faces every time I show it off, and it’s got the lantern and green batt lights. It’s on sale on BG for like 229 right now. I don’t see the GT4 touching it on price or performance.

And the R90C is WITH 4 x 20700 batteries (in battery pack) for that price!
Thats hard to beat!



217.60 actually ;)

Yes, the R90C will put a lot of pressure on this light now. This light made more sense back when I first had the idea 2 years ago. Then it would of been the only real light in the class.

On the plus side it should put some pressure on lumintop to get the prices down as low as possible. There are a few possibly options that could reduce the cost significantly, but still way too early to guess at the final price.

One thing I don’t like about the R90C is that it lacks active thermal regulation. The output only goes down but doesn’t go back up as it cools. The R90C has no heat fins so it doesn’t dissipate heat very well so output drops pretty fast.

same as with ms12, a useless fan inside that doesnt really make much sense, i really hope lumintop can do a better job on the heat management part and keep a decent price.

That’s not correct. The R90C has passive cooling, no fan.

I used it recently during a power outage. I turned it on turbo as a candle indoors, with no other cooling, it lasted a very long time before it kicked down and was quite hot so it has no issue like an early step down. Turbo was more than I needed. I would not want it to automatically return without hitting the switch, this is close to 20k lumens. I switched to using the lantern feature, very good in power outages.

You misunderstood. SKV89 said “active thermal regulation.” This means the software that controls the temperature. Active thermal regulation means the software can reduce, as well as increase, the brightness.

Mortuus was just saying the MS12 is similar. No one said the R90C had a fan. I hope that clears things up.

If I understand correctly, the pinout may be something like this…

 *           ----
 *   Reset -|1  8|- VCC
 * eswitch -|2  7|- voltage divider
 * AUX LED -|3  6|- PWM (FET)
 *     GND -|4  5|- PWM (+1)
 *           ----

This leaves only one pin to control the button LED and the front-facing aux LEDs. To make it control the front-facing aux LEDs separately, it would need to sacrifice the button LED or eliminate the voltage divider somehow. However, if that was resolved, it should be able to have a separate mode for the aux LEDs. They could be recessed into little reflectors or something, and given enough power to maybe have their own separate ramping mode. Perhaps replace muggle mode with red LED mode. But that would also increase the price, for features which may not be worthwhile.

No, he said “same as the ms12”. Same means same in my book. Thanks for clarifying the active thermal regulation; I don’t see it as benefit, would rather not have it personally and I prefer to hit the switch like I said rather than have my torch go up and down on its own

ok i meant that imalent clearly has quality issues, so fan or not they suck on thermal management stuff, thats what i meant im hoping lumintop will do a better job since it will also run passive but with huge heatsinks…

…let’s wait the first reviews…

With Narsil you can set the thermal regulation to a custom temperature, set it to a timed limit or turn it off completely. All big advantages in my book. Thermal regulation that kicks in too soon or too late or not at all can really bug me.

I was just trying to help explain what Mortuus said since I understood him. I guess I failed. Oh well.

adam7027, this sounds like a great idea. I love 4500k!

Active thermal regulation in well designed driver/firmware like the Zebralights work very well. You don’t even notice the ATR kicking in but the lumen output stays much more consistent making it more practical for most use cases.

IMO ATR is no benefit on a thrower, and rarely elsewhere. Once it kicks down I’m not going to keep a thrower on and wait for it to ramp back up, never. Apparently I’m in the minority on this and that’s ok, I wasn’t actually trying to convince anybody to agree with me. You also don’t understand how versatile the R90C is if you think it needs it.

Really depends on how you use your light. For example, if you want to use your Emisar D4 as a tail standing work light, lumen output will drop down to 50 lumens making it useless for that application. It stays really cold at that output but does not know how to climb back up. Whereas a well designed light with ATR of that size will find an equilibrium temperature/output at about 500 lumens making the light very practical for unattended uses.

I was just about to pull the trigger on a GT70 but holy hell, looks like I’ll be waiting a bit.

I’m pretty excited about this beast! I’ve already been showing my wife pictures and talking about so there’s no surprise when a $400(just a guess) flashlight shows up.

The GT4 needs at least one heatpipe spiraled under the shelf, going outside of the flashlight, and rolled at the bottom of the head fin, which will be machined like a continuous large deep threading instead of separated multi || fins.
I’m only dreaming…

See a spiral at the center with a notch in the aluminum base for the heatpipe “go-through” (filled with thermal epoxy).