How to power the 20 watt Monster :)

Hello All!

I know this is my first post, but i need some advise :thumbsup:

I want to buy this >> http://www.dealextreme.com/details.dx/sku.5848
And drive it from a 14v car battery rated around 34ah with a 120ah
alternator. I "Think" i would be able to throw this led in a reflector,
and put a good glass lense on the front of it like i see you all doing
to flashlights here. But i am concerned that the design of this
particular led may not be able to columinate properly for a "Long Throw".

Any advise would certainly be appreciated :twothumbs
I could easily build a driver curcuit with plans if anyone has them

On another note... Check this one out>>
http://www.dealextreme.com/details.dx/sku.5766
I am not too worried about efficiencies with these leds...

Thanks,
Robert M.

I powered mine with 18 x AA cells via a 3.9 ohm resistor in a cheap 6D Maglite clone similar to this this:
http://www.dealextreme.com/details.dx/sku.8488

For automotive use, you would need a driver to step up the 12.6-13.8V to the 17.5-ish this requires, so since a driver is needed, you may be better off with the flavour-of-the-month P7. Easier to find a driver, and easier to collimate.

As another alternative, how about two of these http://www.dealextreme.com/details.dx/sku.5876 each with their own dropper resistors, in parallel?

You might look at an osram 6die, or a p7. I've heard the particular LED you linked to get's crazy hot crazy fast. the other 2 I mentioned need heat sinking as well, but put out more lumens for your buck.

thanks for the suggestions guys :thumbsup:

But my design setup calls for something in the 800-1000 lumen
range for a single emitter package due to the optical requirements
i need. Is there a buck driver setup i can use? or possibly build?

Thanx!

What are you planning on doing?

You can try the Seoul P7. The C bin should be around 700-800 lumen when driven at 3 amps(slightly overdriven).

You'll need a buck driver though.

:welcome:

Gunner12 said:

What are you planning on doing?

You can try the Seoul P7. The C bin should be around 700-800 lumen when driven at 3 amps(slightly overdriven).

You'll need a buck driver though.

:welcome:

Click to expand...

Well, thats a good alternative

But which buck driver do i use when connected to a lighter socket
in a car.. I want to make some EXTREMELY POWERFUL!! Led spotlights
Thanks Everyone

I'm not sure if the SOB1000 drivers work in parallel, but if they do, they could work.

If these drivers work in parallel too, they would also work.

This sounds like an interesting project.

I am curious as to exactly what your requirements are?

Since you are powering it from a lighter socket, have you considered using a LightForce 240 Blitz? It uses a 62138 bulb that is rated 2800 lumens at 12V.
It can also be used as a host for ridiculously bright hotwire mod.

Gunner12 said:

I'm not sure if the SOB1000 drivers work in parallel, but if they do, they could work.

If these drivers work in parallel too, they would also work.

Click to expand...

The sob1000 seems okay, but at 20.00 a pop x 3=60 bones..
Unfortunately thats too much money for just a single P7 led.

The other one from KD may be okay, but can it be modified to
output more current? i need at least the maximum the P7 can
handle. I "Ideally" want to drive it at 3ah. Heatsinking would
be a non-issue for me.. My design calls for 4 seperate P7 style
leds with about 800 lumens each. They will be mounted on a
heatsink with heatpipes, and ambient air to cool them, no fans:thumbsdow
If i find a suitable driver method, then i will post up my "Actual"
intentions , but Not Before, Mwahaha!
I have a lense design that is pretty interesting to say the least

Mee needs more help pweasie!

Thanks,
Robert M.

Sabrewolf said:

Hello All!

I know this is my first post, but i need some advise :thumbsup:

I want to buy this >> http://www.dealextreme.com/details.dx/sku.5848
And drive it from a 14v car battery rated around 34ah with a 120ah
alternator. I "Think" i would be able to throw this led in a reflector,
and put a good glass lense on the front of it like i see you all doing
to flashlights here. But i am concerned that the design of this
particular led may not be able to columinate properly for a "Long Throw".

Any advise would certainly be appreciated :twothumbs
I could easily build a driver curcuit with plans if anyone has them

On another note... Check this one out>>
http://www.dealextreme.com/details.dx/sku.5766
I am not too worried about efficiencies with these leds...

Thanks,
Robert M.

Click to expand...

I just used the first emitter you listed. I'm running it in a dewalt cordless 18V worklight. I tried using the reflector, but no matter what I did it just wouldn't focus correctly, so I had to remove it and go all flood. It is probably a good thing because I have more room for the fan and heatsink, which I need all that I can get. That thing gets SO HOT! It is unreal! I have it mounted on a CPU heatsink that is 2" x 2" x .5" with a 2" x 2" x .75" fan under it that flows 11CFM (which is quite alot for a fan that size) and with the light on for 30 seconds you can not keep your finger on the sink for more than 5 seconds. It is just unreal. The fan is 12V but I did the math and used a resistor to drop the 18V down to 13V. I've also drilled a ton of breather holes in the body of the light for air to flow around to help with cooling. I didn't want to because it's now less water proof, but it's useless if it overheats. If I do this again, I won't use the same emitter.

When you first cut it on, I measured 20V and 1.6A, so that is 32W, so that is pretty serious power. So my input is that if you go with that emitter you need a HUGE heatsink AND fan. Those are a must. Personally, I wouldn't go with them. You also can not focus that emitter, at least easily.

This DC to DC boost converter would work but it's big about 5" X 3" X 2".
http://www.powerstream.com/dc-2171.htm

A-1000 said:

This DC to DC boost converter would work but it's big about 5" X 3" X 2".
http://www.powerstream.com/dc-2171.htm

Click to expand...

Thank You

Sabrewolf said:

Well, thats a good alternative

But which buck driver do i use when connected to a lighter socket
in a car.. I want to make some EXTREMELY POWERFUL!! Led spotlights
Thanks Everyone

Click to expand...

I assume you are not running the engine while running the light.
If the alternator is running you need to suppress the high voltage pulses (in both directions) it produces.

matthew

mpf said:

I assume you are not running the engine while running the light.
If the alternator is running you need to suppress the high voltage pulses (in both directions) it produces.

matthew

Click to expand...

Yeah, i will be running the light with the engine on
I'am making this for a popo officer
But i have changed my mind in the led being used.
I want to use 10 of the P7 leds with 800 lumens
in my design, and therefore need a different driver
than the on mentioned for the 20watt led earlier.
I wont consider a resistor pack due to the amount
of heat it will produce, and the reliability of the leds
when running from it:mecry:

My suggestion for powering from the lighter socket is to use one of the personal computer power supplies that run from a lighter socket. These supply 3A to 5A and come in a range of output voltages and should protect you from spikes as they are designed to power notebooks (but no guarantees).
This is what I am planning for my 12Led 42W torch. With a 15V output it could run with a small resistor, but I will be designing a multi-function buck regulator for it with a build in battery charger and the ability to isolate the battery and run directly from the socket.
Pictures of the 12led light engine are here
https://www.candlepowerforums.com/threads/198040

matthew

mpf said:

My suggestion for powering from the lighter socket is to use one of the personal computer power supplies that run from a lighter socket. These supply 3A to 5A and come in a range of output voltages and should protect you from spikes as they are designed to power notebooks (but no guarantees).
This is what I am planning for my 12Led 42W torch. With a 15V output it could run with a small resistor, but I will be designing a multi-function buck regulator for it with a build in battery charger and the ability to isolate the battery and run directly from the socket.
Pictures of the 12led light engine are here
https://www.candlepowerforums.com/threads/198040

matthew

Click to expand...

Yeah, that may be my route. But the problem is that those DC-DC
adapters are "Constant" current and not "Pulsed". Therefore, the Leds
would get much hotter than driving it with a buck driver/regulator.
Well, at least thats what i "Think" will happen.. (meethinks)

Maybee i'll cannibalize an adapter from an old laptop laying around the
house?

Sooo, the 1,000,000 question is.. If a have a laptop power supply rated
for 2.8 amps and 18v (which i doo), then all i need to do is a
Direct connection to the led? An what if i use multiple P7's in series?
Say, 5 seperate P7's in series to the same supply, would it be enough
current to run them?

Thanks !! :twothumbs

It might work for 5 LEDs in series. The current should be around 1.5-2.8 amp at that voltage depending on the bin of the LED.

Pulsed and constant current will both create heat from the LED, and for the same output, pulsed(as in PWM?) might create more heat then constant current.

You would need a pretty good heatsink for 5 P7s. Maybe a CPU heatsink with a fan would work.

Sabrewolf said:

Yeah, that may be my route. But the problem is that those DC-DC
adapters are "Constant" current and not "Pulsed". Therefore, the Leds
would get much hotter than driving it with a buck driver/regulator.
Well, at least thats what i "Think" will happen.. (meethinks)
.....

Click to expand...

Actually the DC-DC converter is just to provide power to the buck driver/regulator which inturn controls the led current. (i.e. DC-DC is just a battery replacement)
matthew