50W LED floodlight selfmade

[jesterhead]

Hello everyone,
I'd like to share my newest and finished 50W LED project with you:

Details:
- cheap 50W emitter (cold white, 32V@1,5A, ~4000 lumen seller/manufacturer rating) reflector and lens from ebay. Beamangle about 90°
- powered by 8S3P 25.6V 4Ah LiFePo4 battery. Converted to ~32V by DC/DC boost for the LED. The battery can be charged balanced with µC controlled charger or unbalanced with a normal 24V e-scooter charger (see pics).
- controlled by Arduino Nano (current limitation, deep discharge protection, fan control, LCD for battery percentage, running time left, single cell voltages etc.)
- selfmade housing using a carrying handle from a cheap halogen+lead acid flashlight

There are different modes programmed: 100% (~1h45m), 70% (~2h25m), 30%(~4h10m), 10% (~10h), 1% (stopped test after 50h), tip operation and strobe. The different power levels are not linear because of the non-linearity of the LED and constant power consumption by the µC, fan and LCD backlight.

Here some pics

The 50W LED + reflector

unit with lens, reflector, LED, heatsink and fan, on top a pt1000. Had to saw off the edges of the fan for good fitting.

Battery pack (not yet in shrinking tube)

in progress: Arduino Nano with a MCP3208 for measuring the cell voltages. Mosfets for LED and fan, little DC/DC buck for Arduino voltage. The housing for battery and controller is made of plexiglas; the closure head is made of wood (see the long screws)

Complete and painted

Adjustable stand

For size comparison: this is a DIN A 4 paper

Simple e-scooter charger (unbalanced)

Little gadget: a flexible camera stand/tripod can be attached

A bit blurry: inner "reflector" in the tube is selfadhesive aluminium tape

Beam angle


Thanks for watching

 

[Ken_McE]

:bow::bow::bow::bow::bow: We are not worthy... We are not worthy...

 

[PapaLumen]

Very cool

 

[jesterhead]

Just made some beamshots (all same exposure!):

One shot in darkness for reference (the light you see here was really there)

This is a Mag3D with 5xCree Q5 @ ~16,5W (including driver):

And this is the 50W floodlight :

 

[Davekan]

Very nice project. I like it.

 

[jesterhead]

It would be really cool to change the lens movable, so it would be a zoomable flood-to-throw light, but I think that's too complicated for me, got no heavier tools like an angle grinder, turning machine or so. Just what is possible in the living room/my desk

Here 4 more shots:

again, reference

Mag 3D:

35W HID + 2x Cree Q5@1A each mounted on the bike:

And the 50W LED (think some little insect just crossed the beam):

 

[Old-Lumens]

Fantastic! I love DIY lights. That's really something. What type of lens? An aspheric? What does the beam look like without the lens (if you know)?

 

[jesterhead]

This is the lens+reflector http://www.ebay.de/itm/78mm-Lens-82...Electrical_Test_Equipment&hash=item1e72a44386
Without the lens the LED beam angle is even wider than in the pictures with lens. It is maybe a bit wider than a Q5 or P7 without any optics since the 50W LED array hasn't any lens/optics itself:

The pictures were made at the beginning for testing when i got the LED. I think it's difficult to estimate the beam angle because the carpet doesn't let the light shine homogeneously. There is no spot though it looks like
Maybe you can see here better how wide the angle is:

 

[sunshinemore]

Amazing!! It's cool.:twothumbs:twothumbs:twothumbs

 

[AlexGroove]

This looks amazing!! Great job!

 

[Ultrawipf]

This is great. Almost missed your project.

Your build is so clean and i love your housing. What is the weight including all cells?
Are there videos available?

Some days ago i posted another thread with a very similiar project with a 100w led. (Project log here: http://hackaday.io/project/1789)

 

[StrikerofDeath]

very cool project!

how do constant current control with the arduino?

 

[jesterhead]

I'm sorry, I completely forgot this thread.
The constant current control is simple, measure current through shunt resistor, and if it is to high (current raises since the led gets warm), I lower the output via PWM.
Maybe I can make some video material in the next days.
The complete lamp weighs 3 kg.