Homebuilt ROVs Forum

Here is another update on the Bridgelux LED's:



In the video I did a full system test with the whole power system.

The power is supplied by a 48v supply on the surface, then it is converter to 12v with a golf cart converter, then a step up converter takes 12v and steps it p to 21v to power the LED's.
I am using a Phidgets dual SSR relay to control the LED's, and my custom ROV Control board to control the relay.

Thanks,
njs552

Looks really good! Very nice setup!
I have been creating my shopping list pretty much based on what you have been demonstrating. Just out of curiosity, are you planning on having more then one of the LEDs on your ROV?

Thanks!

I am planning on having 2 of the LED's on the ROV, one on each side of the pilot camera to minimize light backscatter. I think 2200 lumens will do the trick.

Thanks,
njs552

I would think 2200lm should be MORE then enough!

Are you planning on running both LEDs off of one step up PS? I think you mentioned that the step up that you have will handle 3A?

Yes. Both LED's are running off the one step up converter, and it is rated at 3A.

I got the step up converter on eBay, and I usually only run things from eBay to about 30% to 80% of their rating, but this board is high quality, and has active voltage monitoring so no matter what your input voltage is, it will output the voltage you select. So far it is a great board.

Thanks,
Njs552

Does it happen to look like this? I have this for my setup and it works excellent.



http://www.ebay.ca/itm/2x-150W-DC-DC-Bo ... 1c35b6d343

Yes. That is it exactly.

Also, here is another update on the LED housings:


Will make another one this coming week as well and then I will test them in water in the next couple of weeks.

Thanks,
Njs552

Supply a high-power-led without driver will destroy it.

Guys what you do there. You step up from 12V onboard voltage (did you convert it still from land over thether?) to 21V only for LED? Why dont you use LEDs in your voltage-area?

High-Power-LEDs have to be driven by constant current, not constant voltage! Without (current) driver you will burn it... not today, but led will loose lumen power with time.
So its your way to loose power for step-up and you will burn led down without driver. Cant understand why you dont use LEDs like CREE T6 or something else? With constant current driver (not step down or else) you will be able to dim LEDs over PWM easily.

I use 24x Cree T6 Emitter(sorry only german link) (8x3 in line) @1000mA.

LEDs need typ. 2,9V (3xin line) so minimum 8,7V + 1V driver voltage drop = 9,7V min.
Driver works with 14,8V (4S Lipoly)... takes only ~700mA @ 12,6V (lipo minimum) for 3 LEDs
8 Driver @ 700mA = 5,6A...

So i use 24x Cree T6 with ~500 lumen/each makes 10200 Lumen at 12.6V with 5,6A... think this is much better!

@ROVER3D

I am sending 48vdc down my tether to the ROV. On board there are DC to DC converters that step down 48v to 12v. From there 12v is stepped up to 21v for the LED's.

The reason I am using 21v LED's is because a 12v LED of the same price does not produce as many lumens as a higher voltage LED's. There are 12v LED's that do produce around 1000 Lumens, but they draw on the order of 1.5A if I remember correctly, but they are also more expensive.

These LED's cost about $8, and if they break or loose lumen ouput after awhile it would not be a huge expense to replace them. My LED housings are also designed so that the LED's can be swapped out easily if need be.

Can you recommend a LED driver? I have not been able away that are good for my application. They all seem to be powered off 110vAC, and I am only using DC power on my ROV and tether because of interfernce issues. I am certainly willing to use a driver, and I have space in my pressure vessel, but I just have been unable to locate anything good.

How big is your array space wise? And do you really need 10,000 Lumen... what are you using as a driver for all those LED's?

Thanks,
Njs552

Hey,

i think this is your problem because of using LEDs for other voltages. In disco-light-equitment you find many very powerfull led-arrays but drivers avalible only for 110/220AC. So you buy a cheap LED and need other "expensive" converter and you still plan for burned LEDs. I can understand that ROVs are very expensive hobbies and you wanna try your own but think about comming costs and incorrect functionality. You wont have much fun with this way.

You will not know how your leds burn. When they do maybe something will go wrong too...

I can recommend Meanwell Drivers (http://www.meanwell.com/search/ldd-hs/LDD-HS-spec.pdf)
You can use it for your application when powering it over 22V (21LED + 1V voltage drop) and use 1000mA version.

Myself using 8 of them. I have 4x 3LED-arrays in front (each side 2x 3 vertical in line behind 30° optics)



and 4 down.(see only 3 little dots in line)



So ich can change light for many situations and have anytime enough of it. Think about shades with only 2 leds.