The There Are No Stupid Questions Thread

Maybe someone can explain this to me, as I seem to be too dense to comprehend it.

Why is it that if I were to go to Amazon and buy X (coffee-grinder, bluetoof earmuffs, sock-hangers, anything), within a week I’d get inundated with emails from them that I “might be interested” in another X (coffee-grinder, bluetoof earmuffs, sock-hangers, etc.), as if one just ain’t enough?

Im new to flashlights and own a few.

What are the differences in drivers used in todays hi powered lights. I see FET, buck, boost, I don’t know what any of them mean, and why sometimes one is used over another. Help?

You must not have clicked the “don’t send me email promotions” box. I never get emails like that, yet I buy from them.

Mmm, maybe I should.

Some, related, things are useful. Like, buy bbq tongs and get recs for cookbooks about outdoor grillin’ recipes or something. But not 13 ads for more tongs.

Are you new to Google too? :wink:
Simple search took me all of 15 secs to find a few sites to help explain:

Flashlight WIKI Drivers

Reddit - Drivers - boost, buck, linear, FET, direct?


Wow, for some reason I did not see your post. Try this thread. Understanding the difference between Linear, Buck, Boost and Direct Drive drivers

Excellent follow-up Jason. It’s always nice to have some photos & diagrams. Using multiple sources definitely helps expand understanding.

I have One Emisar light. The K1 SBT90.2. Great light.

Question: How come no where on the light OR the box is Emisar inscribed? Never had a light where the manufacturer left that info. off of their product.

It’s technically not an Emisar, it’s a Noctigon. Hank at Intl-outdoor is behind both brands.

Yeah Emisar is lights with linear chips + direct drive, Noctigon is lights that use constant current or boost drivers.

If you can see the Internet.
the Internet can see you.

Someone is always willing to pay for every click and every mouse hover.
I wonder if someday some mogul will say:
You know, I’m not sure paying to collect all this data is really doing us any good.
Lets drop the whole thing.

24Hrs later the WWW collapses.

All the Best,’Jeff

I’ve got an SP70 with the 70.2 LED. I really like it.
It’s big and heavy and clunky.
If I was going on and extended S&R type of thing (which I never will I suspect).
It’s the one I would grab.
PWM is so fast you will never see it. Like 19K if I remember.

Being able to turn the light off with the side switch is a big plus over, say, the L6.

The only thing I don’t like is the position of the front strap attachment.
It’s right in front of the switch. The clip folds back and blocks the switch.
Also it makes the light front heavy. So carrying by the strap, slowly the light dips toward the ground.

Move the front connection point closer to the font fixes this.
Wish is was available in a warmer color. Warm works better for me outside.

All the Best,

The first batches used a CW, maybe 6000-6500K, but now they offer it in 4700-5300K. Nice for new buyers, but those that already have it would have to swap it out.

So… Internet = The Abyss.

Makes sense.

Mmm, I can deal with that.

Thanks for sharing your experience with the SP70, Jeff. I decided I’m going to wait on getting one. The only use I’d have of it is on a few occasions during the summer. My other lights handle everything else just fine during the rest of the year. It is good to see a solid neutral white emitter now provided. I may try to pick up one on discount at the end of the year.

Thanks. no I’m not new to google… I did try googling information but still couldn’t find anything that helped me understand the concept. I appreciate the information. Just figured I could get more direct info from the good people on blf.

Thank you!


I guess all the information we hear is not correct. I read on one of these threads that it was an Emisar.

The Jetbeam-II also has its driver glued but there’s a very thin brass washer. If rubbed-off copper is actually the problem, I’d see if I can find such a washer or a sheet of brass foil to make one.

There is a whole complicated situation when it comes to Chinese manufacturers of flashlights. This is why you see clones and more than one version of the same light. Hank has his company and he decided to use two brand names to distinguish two different lines of lights. Emisar and Noctigon. He did the Noctigon Meteor several years ago (2016 I think), but all his lights since then were the Emisar brand. So folks tend to associate all his lights as Emisar and he just recently decided to release the K1 under the Noctigon brand. People know it’s from the “guy that does the Emisars” and it has the same user interface as the Emisars so you can see how people might confuse it with an Emisar.