Powering an Astrolux FT03 via 12vdc system

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RiverRat
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Powering an Astrolux FT03 via 12vdc system

After toying around with my new FT03 sst40 light, it dawned on me that I could make an impressively bright light bar, with five or six of the flashlight heads.
My son and I spend nearly every weekend, rain or shine, prowling the waters near us, on a 50ft houseboat.
I have a home brew HID spotlight on the roof, but I made it with an old halogen setup, that’s controlled by a handle inside the cabin. In rough seas, it can be challenging to run the light and steer the boat.
I’ve searched for an answer to my question, but still can’t seem to determine the best power supply for running the lights from the boat’s 12v wiring.
I can weld, braze, and solder, so a housing and associated hardware isn’t a concern, but I’ve thus far seen an overwhelming amount of step down converters, and can only wonder if I’d need to ensure that they yielded 30amps of 3.7v current to the fixtures.
With the cost of reflectors and such, purchasing a handful of complete lights seemed like a big head start towards the desired result. From there I’d have to figure out whether to bypass the internal flashlight switches/drivers,

RiverRat

dougjones31
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The ft03 lights would need a 4.2v constant current power supply. That is easy….the problem is the drivers are probably 6amp drivers, So your dc to dc converter would need to handle 30 amps or you would need multiple converters. A quick amazon search shows adjustable dc to dc power supply that is 12amp rated for $17. buy 3 of those. That power supply is adjustable so you should even be able to dim the light bar from one knob if you even want that option. Just put all the lights in turbo mode, which is direct drive, and adjust the input voltage down to dim them.You may be able to find an adjustable “dc buck converter” that is 30 amp rated and just use 1. If you drill the tail caps and mount a plug in them then you could even make it where you could remove the flashlight from the light bar and use it like normal. The thing you probably are not considering is the light thermal protection is going to kick in and limit the output brightness,,,,,so a water cooled solution should be considered.. which should not be too hard since this is for a boat! I am thinking PVC pipe mounts with gaskets to encase the flashlight head. Water pumped from the livewell pump.

Jake TheTool
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Thanks! That is exactly what I needed to know, and I appreciate the detailed explanation.
I have a pile of heatsinks, and a handful of small dc fans, but might be tempted to plumb some tubing from one of our 100 gallon fresh water tanks.
One water tank is currently heated with a dc element that serves as a dump load for a solar charge controller, but with intermittent use of a light bar, I’d expect the 100 gallons of cool water in the other tank to help prevent any thermal issues.
Hopefully I’ll have a few pictures to post, someday soon. Thanks, again!

dthrckt
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Sounds like a fun project, and a fun boat. Looking forward to pictures.

dougjones31
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Remember…Wiring them parallel will keep voltage requirement at 4.2v no matter how many lights you use. but you still need 6 amps for each light.

Do not try to wire 3 lights straight to the battery. 14.4v for a fully charged battery divided by 3 for 3 lights in series will give you 4.8 v which will probably fry the drivers in the lights. You have to use a constant current dc to dc power converter, The one I mentioned that I saw on amazon was 12 amp. I would wire 2 lights in parallel and set the output voltage for 4.2 v for that one. this would insure fullpower Turbo all the time….assuming you cool the lights!

djmcconn
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This is sounding crazier and better every post. I’m following and if you need, I’ll hold your beverage of choice!

dthrckt
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I agree, I would suggest a bunch of rerail lights, but obviously there is something in the works.

SammysHP
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How do you want to turn them on all at the same time? Just connecting power won’t do anything. A constant current source with all in parallel will fry all lights because they use direct-drive drivers and rely on the internal resistance of the battery.

If you want to use the FT03, just use the head with the reflector and LED. Cut off the head just below the shelf, mount a big heatsink onto it. Then use an appropriate driver for every light that accepts 8-18 V input and outputs 6 A (the FT03 pulls more with a fresh battery, but I assume you want a bit more lifetime). The output will be around 3 V, so a switching converter will be mandatory.

dougjones31
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They will run off of a constant current power source….been there…done that. Memory mode will turn them all on turbo when you power them. If he runs pairs on the 12amp power supply and runs 3 power supplies with 6 lights….he can turn them all on by putting a switch on the battery power to the 3 power converters.

Those magical DC Pixies are the same whether they come from a lithium cell or a power supply! the power supply has resistance anyway and the wires to the led are the main resistance in the circuit.

BUT,,,,,,,looks like maximun surge current for the SST40 is 8 amps. oops my bad. https://download.luminus.com/datasheets/Luminus_SST-40-W_Datasheet.pdf

So go a little bigger than that 12amp power supply. Worst case is you fry the power supply though.

Bart1080
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why not keep it simple and just put a big LED bar light on top….you know, the ones the put on 4WD’s. They just connect to 12 volts or 2 or more LED driving lights.

No issues with thermal cut out of tourches, just plug and play.
At 9,600 lumens, 441,000cd and a distance of ~500 to 600m (1500 to 1800 feet), runs on 12v or 24v, made for outdoors, you cant go wrong.

https://www.stedi.com.au/st4k-22-inch-double-row-40-led-light-bar.html

dougjones31
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What fun is that? lol

Besides, those light bar specs are waaaay overstated as we all know.

SammysHP
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dougjones31 wrote:

BUT,,,,,,,looks like maximun surge current for the SST40 is 8 amps. oops my bad. https://download.luminus.com/datasheets/Luminus_SST-40-W_Datasheet.pdf

So go a little bigger than that 12amp power supply. Worst case is you fry the power supply though.


LEDs are current controlled, not voltage. If you provide 10 A or more to a SST-40 its bond wires go poof and there is no more light. A power supply with 3,5 V and 12 A will kill it easily.
Jake TheTool
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I appreciate the help, and value all input.
My son and I have light bars, on the front of our ATVs, and although they do a good job of illuminating a wide area, the throw has never impressed me.
I enjoy metal working, and keep a stockpile of various types of metals
The boat Id mount the light to is our beloved 50ft houseboat. All of our navigation, and interior lighting, is of a home brewed type, and when we wanted rod holders, I made those too.
We’ve traveled an estimated 4,000 miles on the boat, doing mostly short trips of 60 to 150 miles, typically with a smaller boat in tow behind us. Before beginning our adventures, we completed a gasoline to turbo diesel conversion, with the addition of a surface piercing drive.
The boat came with a large, high voltage solar panel, mounted to the roof, but the panel hadn’t been wired. We ran welding cables from it, to an MPPT charge controller, and then to 400ah of lead acid deep cycle storage. We also have a smaller PWM panel charging a group 8D starting battery, and controlling our navigation lights. When there’s no output from the panel, our lights turn on.
I hope to switch to lithium iron phosphate storage batteries, before next summer, and in doing so, reduce our hull weight significantly. .
We see plenty of boats running LED light bars, and can’t help despising them(the light bars). Most of the users seem oblivious to the fact that they’re blinding all oncoming traffic, and on many occasions, my 13yr old son will illuminate in front of them, as they pass by, with one or two of our FT03 lights. It’s never possible to determine the exact type of light bar they’re using, but I have yet to see one that will out throw the little handhelds.
An impressively powerful thrower, custom made and mounted roughly 14ft above the water, might be overkill, but we’d use it responsibly, in rough seas or remote areas, and we’d build it together.
Even at 10yrs old, my son was more confident and competent, in the woods and on the water, than many of my grown friends, but he’s been prowling the woods with me, in pursuit of archaeological finds, since he was one!
Throughout the many miles traveled on our boat, I’ve spent very little time at the helm. He’s the captain, and has been, since day one.
He too wants to build an impressive light of our own, and the way I see it, he’ll learn a little, along the way. .