Tsar Flashlight

[ddrueding]

Based on the discussion in the LED thread, I sent JTR a message. Here is how it has gone so far:

If you are interested in building something similar, let me know. I'll consider funding it (once we have a budget) and let you play for a while before taking it from you.

Hi Dave,

I'll think about it. Heck, if it's cheap enough I might build myself one while I'm building yours. Let me see what's available as far as emitters go. I have a gut feeling going with high-bin Crees would be more viable but it might end up costing a lot more. I've actually wanted to build an LED light of some type putting out ~100K lumens.

Note that this is a pretty busy month for my consulting project, but if this project doesn't take a huge amount of time I might squeeze it in. It looks like the builder used off-the-shelf Chinese regulators to power the emitters. Those are readily available on eBay, and pretty inexpensive ( from under $1 to maybe $25, depending upon how much power they can handle ). Battery could be any one of a number of sources, like conventional li-ion, LiFePO4, NiMH, etc. Given the high current requirements, probably LiFePO4 would make the most sense. It might also be interesting to have an option of power it indoors from a 12V or 24V power supply. You could build your own indoor sun room! And of course knowing me I'd probably make it dimmable. If it runs for 10 minutes putting out 100K lumens then it'll run for something like 20 hours putting out 1,000 lumens. That might come in handy during a blackout.

I have a bunch of 3-cell and 4-cell Lipo packs from my drone stuff. 5Ah and 8Ah batteries that should be enough for some serious use. I suspect most of my applications would be running on battery or tied into an automotive system, so optimizing for 12v+/- would make the most sense. 100k+ lumens would be a nice target.

Hi Dave,

Just starting some preliminary research. For the emitters, there are any number of 100 watt eBay LEDs ranging in price from about $8 to over $30. Most of the lower priced ones aren't terribly efficient, and frankly they seem like garbage to me. The best one seems to be this. They claim 8,000 to 10,000 lumens. Of course, this being eBay, I'd take that with a grain of salt. On Mouser I looked at a bunch of high lumen COB (chip-on-board) LEDs. The Crees seemed to come in at 200 lumens per dollar or more. The best bang for the buck in terms of lumens per dollar are these or these but they're on order. ~17,800 lumens for $45.73, and efficiency of ~125 lm/W. The second option, which is available, is this. These are 11,430 lumens @121 lm/W for $41.60. Not as good bang for the buck as the other two, but they are available, and the 35V operating voltage is a lot easier to work with than the 54V of the other two. Since Mouser charges me sales tax, these would be $45.30 each plus shipping. Note however there is quantity discount for 10. That brings the cost to only $40.03 with tax. If I made myself a light and we order 5 spares, we would only be paying $34.96 each with sales tax.

I found what I think might be a great regulator for only $4.31 each. You would need one per LED, so ten total.

I haven't yet bothered researching a heatsink, but I can probably cobble together something for under $50. Using the more efficient LEDs, my estimates are we would only need to dissipate about 500 to 550 watts of waste heat.

The rough total then for materials should likely come in at $500, give or take. That assumes you'll be using some of your spare batteries as the power source. I'm not sure yet how much the labor charge might be, but I don't think this is a very labor intensive project. My guess might be $200 tops. There isn't much design involved in this project. The hardest part might be figuring out how to adjust the regulators, and also adding on some circuitry so you can vary the intensity.

I don't know if you'll also want optics to focus the output. Those would of course cost more. However, I think they're something you can easily add yourself once you have the finished light in hand.

All in all this is a somewhat expensive project but probably not as costly as I had thought. A few years ago something like this wouldn't have even been feasible. I also like the fact this is a modular design. If making a light with ten emitters is too costly, the project can easily be scaled down to five or three or even just one.

Thanks for putting in the effort. This seems quite reasonable for what it is. Adding even more modularity is appealing to me; I've had really good luck with heatsinks from this manufacturer that are available on Amazon.

If 2" of this 10" wide x 3" tall profile is enough to handle 3 emitters and regulators, I'd be tempted to build them as modules and be able to hang them from a rail. 4 modules (12 LEDs total) could hang from some aluminum square bar and be daisy-chain-able using XT60 or similar connectors (those are what my batteries already have).

As always, I know just enough to ask stupid questions. All ideas above are just that and very flexible. The available "Plan B" LEDs seem fine. I'll send you a check and we can get started?

Hi Dave,

By Plan B LEDS, I assume you mean these?

Making these in groups of three, each with a connection, will enable me to test each module with my 12V, 60 A power supply. That simplifies things a lot given that I won't need a 12V source capable of putting out in excess of 100 amps.

This might be an alternate idea for the heat sink. One heat sink like this with a 120mm fan could deal with the heat just fine. It's worth noting given the limits of run time due to battery capacity that the heat sink's thermal mass will play an important part. The battery may well be depleted before the heat sink temperature rises to levels which might be of concern even without a fan. I'll have to experiment with this. The heat sinks you picked should work fine for 3 emitters and regulators if we want to go that route instead. I guess you would mount them from the rail such that the fins were parallel in order to use one fan to cool all the modules.

$1K will easily cover labor and materials for this project. I can order the stuff I know we're sure of for now (the emitters and regulators) before we decide on exactly what heat sink arrangement and connectors we'll use. This will let me test the concept using some heat sinks I have. I'll probably built myself one for now with maybe 4 emitters, perhaps more depending upon how much money I want to spend.

I guess that's it for the time being. Yes, let's definitely get started and blow what the other guy did out of the water!

Yup, those are the emitters that I was talking about. Also optics; how narrow a beam is possible with normal close-fit optics? I'll also need to look at some kind of shroud to prevent people who are in line with the unit from being hit with any of the light directly.

I'll be talking with a buddy who does search and rescue from aircraft later, how would this compare to the normal searchlights they use?

Hi Dave,

I'm thinking with an aspheric optic like this we could get a very narrow beam. Note that the beam angle with this optic depends upon how far from the emitter it is. They say you can get 5°.

This might be comparable to an aircraft searchlight. The specs for this one are a 1600 watt xenon short arc lamp and a 4° to 20° beam. IIRC, a xenon arc lamp is about 50 lm/W, so we're talking maybe 80K lumens here. If we focus the 120K+ lumens from 12 emitters into a fairly tight beam we may have something very similar.

A shroud is probably a good idea if you're using optics here. The focused beam will be much, much brighter than full sunlight. It can easily cause eye damage (that's why I'm probably not using optics on mine).

 

[ddrueding]

So. Questions? Comments? Anyone else interested?

 

[Stereodude]

I'm in for pictures and video. That you and mounting it to a quad and starting a frenzy of UFO sightings.

 

[Handruin]

I'm certainly interested to see how it turns out and everything else involved with the build. I don't personally need something as powerful as that but I can appreciate it and live vicariously through you two. If it's possible, might be worth documenting the build process to share with others if you feel up to it. If not I respect that it can take a lot of time to do that and also that you might not want to share the full details of the project.

 

[LunarMist]

Why is this a TSAR? What is the purpose of the light?

 

[jtr1962]

Why is this a TSAR? What is the purpose of the light?

From my observation of the light this project was inspired by in this thread:

In concept this reminds me of the former Soviet Union's Tsar Bomba. It worked, but in the end it was far too powerful to be of any practical use. Same thing here.

As to the purpose, for me anyway it'll be if I need to flood any area with a huge amount of light. Since I plan to make it dimmable, it'll also double as a emergency light in case of power failure.

 

[LunarMist]

From my observation of the light this project was inspired by in this thread:

In concept this reminds me of the former Soviet Union's Tsar Bomba. It worked, but in the end it was far too powerful to be of any practical use. Same thing here.

As to the purpose, for me anyway it'll be if I need to flood any area with a huge amount of light. Since I plan to make it dimmable, it'll also double as a emergency light in case of power failure.

I hope you are both well insured if things go south.

 

[CougTek]

Just don't aim it at airplanes. It might not be a laser, but it could blind a pilot nonetheless if it is that powerful and if the plane is flighing low.

 

[jtr1962]

I have no plans to aim it at anything in the sky. In NYC especially that's likely to bring a SWAT team to my door in short order.

 

[ddrueding]

Pointing it towards the sky is actually something I'm considering for particular events, but that will involve permits and permission from the FAA along with coordination of local law enforcement. I just finished a weekend of parades where I had heavy construction equipment lit with tens of thousands of lights synced to music. Something like this beaming straight up could be an impressive sight (some fraction of the Luxor SkyBeam's 140,000 xenon watts).

 

[jtr1962]

For anyone who might be on the fence about having me make one for them, remember the design is modular. We can have as few modules as you want and the cost and size will be proportionately less (maybe ~$100 per module plus batteries). For example, a 1 module light might comfortably fit on a microprocessor heat sink.

 

[Howell]

Sounds fun. I have popcorn.

 

[LunarMist]

Asbestos suit and emergency services on speed dial...

 

[jtr1962]

I hope you are both well insured if things go south.

Asbestos suit and emergency services on speed dial...

Not sure much can go wrong here. I've already dealt with the power levels these things will use from years of playing with thermoelectrics. Heat output and heat sinking requirements are similar. As for the light output, it's certainly not intense enough to start fires, at least not unless I'm stupid enough to hold a piece of paper a few inches away.

 

[jtr1962]

I'm ordering the regulators today since they'll probably take ~10 days to get here from China. I'll order 20 for now. Later this week, or early next, I'll order the emitters and other parts. The number will depend upon how much interest there is in having me build these beyond what me and Dave want. For now I'm leaning towards a 4 to 8 emitter light for myself and Dave wants a 12-emitter light. That leaves us 5 to 9 pieces short of reaching the next price break for 25 pieces.

 

[jtr1962]

Regulators and optics ordered, 20 pieces of each.

 

[Stereodude]

How can the regulators have both adjustable voltage and be constant current? :scratch:

 

[jtr1962]

How can the regulators have both adjustable voltage and be constant current? :scratch:

The adjustable voltage would be the maximum the output reaches under no load conditions, or when the current is less than the constant current setting. Since these emitters are ~35V @ 2.7A, maybe I would adjust the output under no load to slightly more, perhaps 36V. Unless the emitter fails, the regulators would then be operating in constant current mode all the time.

 

[Stereodude]

The adjustable voltage would be the maximum the output reaches under no load conditions, or when the current is less than the constant current setting. Since these emitters are ~35V @ 2.7A, maybe I would adjust the output under no load to slightly more, perhaps 36V. Unless the emitter fails, the regulators would then be operating in constant current mode all the time.

It's an oddly worded listing if it works how you describe. Then again, the seller is in Asia and their English skills may be lacking.

 

[jtr1962]

It's an oddly worded listing if it works how you describe. Then again, the seller is in Asia and their English skills may be lacking.

I think that's the case. I've seen product listings with far worse descriptions than that.

 

[LunarMist]

Not sure much can go wrong here. I've already dealt with the power levels these things will use from years of playing with thermoelectrics. Heat output and heat sinking requirements are similar. As for the light output, it's certainly not intense enough to start fires, at least not unless I'm stupid enough to hold a piece of paper a few inches away.

I'm kind of joking there, but David could do something wild and crazy.

 

[ddrueding]

I'm kind of joking there, but David could do something wild and crazy.

I think commisioning such a thing at all is pretty wild and crazy. I have my pilot friend checking with the FAA for restrictions on either pointing it towards the sky or operating it from an aircraft.

 

[ddrueding]

For mobile applications, I'll likely power it with a bank of these. Not sure what the power distribution will look like, worst case I run a few off each battery and run them completely independently.

 

[Stereodude]

For mobile applications, I'll likely power it with a bank of these. Not sure what the power distribution will look like, worst case I run a few off each battery and run them completely independently.

Why hardcases? I'd recommend ChinaHobbyLine's LiPos. Nice quality at a great price, but they've been offline for a few months working on a new website. According to their facebook page you can still e-mail them to buy batteries. However, I realize you probably want to be able to browse and don't know exactly what you want.

 

[LunarMist]

For mobile applications, I'll likely power it with a bank of these. Not sure what the power distribution will look like, worst case I run a few off each battery and run them completely independently.

Why don't you attach it to the bars on the truck?

 

[jtr1962]

For mobile applications, I'll likely power it with a bank of these. Not sure what the power distribution will look like, worst case I run a few off each battery and run them completely independently.

Figure about 8 amps per module. In theory that battery might be able to power all 12 modules but you'll get 3 minutes run time if you're lucky. I'd probably recommend getting as many batteries as you can afford to maximize run time. I can connect as many or as few modules per battery as you want. Let me know the mating connectors for the battery so the finished product will be plug and play.

 

[Stereodude]

I wouldn't use a 20C pack though. 40C or 50C would be better.

 

[LunarMist]

I wouldn't use a 20C pack though. 40C or 50C would be better.

Sure, but I'd rather have a larger battery pack. Who wants a big honking searchlight that only runs for a few minutes? :scratch:

 

[ddrueding]

Why hardcases? I'd recommend ChinaHobbyLine's LiPos. Nice quality at a great price, but they've been offline for a few months working on a new website. According to their facebook page you can still e-mail them to buy batteries. However, I realize you probably want to be able to browse and don't know exactly what you want.

I feel more comfortable hard-mounting hardcases to the sides of heatsinks. I'll probably use brackets of some kind.

Why don't you attach it to the bars on the truck?

When it is on a vehicle or other machine I can draw power from them. When it is handheld I'll need another power source.

Figure about 8 amps per module. In theory that battery might be able to power all 12 modules but you'll get 3 minutes run time if you're lucky. I'd probably recommend getting as many batteries as you can afford to maximize run time. I can connect as many or as few modules per battery as you want. Let me know the mating connectors for the battery so the finished product will be plug and play.

I'd be running at least 4-6 of them, possibly more.

I wouldn't use a 20C pack though. 40C or 50C would be better.

If I'm running multiple packs 20C should be fine. The $/Ah goes up considerably with the faster batteries.

 

[LunarMist]

When it is on a vehicle or other machine I can draw power from them. When it is handheld I'll need another power source.

How much does that whole setup with all the lights and battery packs weigh? Is it really all handheld or does something go on your back? You must be a pack mule.

 

[Stereodude]

Someone sent this to me yesterday. It seems fitting here too.

http://xkcd.com/1603

 

[Handruin]

Someone sent this to me yesterday. It seems fitting here too.

http://xkcd.com/1603

The secondary mouse-over joke is the best on that one.

 

[Stereodude]

The secondary mouse-over joke is the best on that one.

Heh, I didn't notice that one until you pointed it out.

 

[ddrueding]

Awesome. I've shared this project with a few IRL friends (OK, I only have a couple IRL friends...) and not one asked "why?". This is why they are my friends.

 

[Handruin]

When these get built, if you all decide to share it elsewhere in the world, just give me a heads up so I'm aware if our site goes down due to traffic. :-D I can certainly understand why you would want this...it's hella-geeky and fun. I just don't have that kind of disposable income at the moment for a project like this otherwise I'd be on board with this fun.

 

[ddrueding]

I'm actually really excited by the scalability of this project. I have some friends with more disposable income and a slowly blooming geek streak that might like one 5x to 10x the size.

 

[jtr1962]

I'm actually really excited by the scalability of this project. I have some friends with more disposable income and a slowly blooming geek streak that might like one 5x to 10x the size.

Assuming you have some way to power this, it could of course be scaled up to 20 modules, 50 modules, etc. For the time being I'm ordering 16 emitters-12 for your light, 4 for mine. We won't hit the price break for 25 pieces this time, but who knows in the future?

 

[LunarMist]

I'm actually really excited by the scalability of this project. I have some friends with more disposable income and a slowly blooming geek streak that might like one 5x to 10x the size.

At some point it would be more practical to have fewer, more powerful lights, no? What do the pros do?
It reminds me of the commie rocket in the 60s that had a crapload of smallish engines and kept blowing up.

 

[ddrueding]

At some point it would be more practical to have fewer, more powerful lights, no? What do the pros do?
It reminds me of the commie rocket in the 60s that had a crapload of smallish engines and kept blowing up.

The pros don't do this kind of thing, as there is no practical or commercial application. There are very few more powerful LEDs, you are quickly approaching scanning laser levels of power. The current most powerful light is the one on top of the Luxor in Vegas, and they use 39x 7kW Xenon bulbs that heat the entire room they are in to 300F and require two full-time staff. This is clearly old tech (built in 1993).

 

[sdbardwick]

Was in Vegas this weekend and heard a local refer to the Luxor light as the "bat beacon", so I had to find out why.