LED light

Badger UK

Badger UK

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Brian Ardrey
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I've just found some 50w LED's (sadly, they're in China at the moment, but they're on their way here) and I'm going to make myself a light.

Anyone done anything similar?

Did it work?
 
I've tried in the past by using IR LEDs but as i have pretty much no grasp with electronics i almost blew up the batteries, (never seen a 9v battery heat up that quickly before)

a kind chap on youtube sent me this link http://led.linear1.org/led.wiz which should be able to write out a wiring layout for your set up and which resistors to use :D

i would so love to do this again but as i've got no idea how to workout which is the positive terminal of the LEDs after trimming them to make it neat. or whether or not just to start afresh

Mine was mounted to perspex and then to a cokin P holder so could use it as a "ring flash" styley. shall have to dig it out and try again.
 
On the LEDs there is usually a flat side which represents the negative...... helps you tell once you have cut the legs down!!

Hope this helps
 
kiko said:
I've tried in the past by using IR LEDs but as i have pretty much no grasp with electronics i almost blew up the batteries, (never seen a 9v battery heat up that quickly before)

a kind chap on youtube sent me this link http://led.linear1.org/led.wiz which should be able to write out a wiring layout for your set up and which resistors to use :D

i would so love to do this again but as i've got no idea how to workout which is the positive terminal of the LEDs after trimming them to make it neat. or whether or not just to start afresh

Mine was mounted to perspex and then to a cokin P holder so could use it as a "ring flash" styley. shall have to dig it out and try again.
Click to expand...



I'll let you know how I get on.

Badger
 
kiko said:
Mine was mounted to perspex and then to a cokin P holder so could use it as a "ring flash" styley. shall have to dig it out and try again.
Click to expand...


I like the Cokin idea. I was going to mount it on a hotshoe of some sort and try to use it a bit like a beauty dish.

See what happens.
 
5761989821_bbeeac98f9_z.jpg


thats how it ended up looking after wiring but as the battery wanted to explode i never finished it. i stupidly used superglue to fix the LEDs in place so that i think is a great waste of £15 ish on LEDs.

now that i've got an infrared camera i think i'll have to reattempt building this, although i may just wait to see which lens i end up with as i wanna get something wider than my 18-70mm
 
Kiko, I don't see a current limiting resistor in your picture. I'm assuming it's round the back. What value is it?
 
Stratman said:
Kiko, I don't see a current limiting resistor in your picture. I'm assuming it's round the back. What value is it?
Click to expand...

that's why i almost blew up a battery or two.

if i run with the same 12 LEDs again which i probably will, and run it off a 9v battery then running 3 parallel sets of 4LEDs in series i would need to have 3 '22ohm' resistors in parrallel.

thats if i've understood the diagram. look on the link i provided earlier as that can work out what resistors you need.
the maplins website actually list the specific details of the LEDs

I'm just working out how many i would need, to get upto 100W worth of power or more.
the ones i'm looking at
 
duttytd said:
Is this the same as a ring flash?
Click to expand...

kinda of, you can get on the market some LED ring lights for macro work with SLRs and Compacts. the a few of bigger ringflashes actually have 2 bulbs which give alot more power and control (i'm pretty sure on the metz ones you can offset the power to either side)


if your good at fabrication, soldering and have a spare £20-30 you should be able to make a half decent one.
 
kiko said:
that's why i almost blew up a battery or two.

if i run with the same 12 LEDs again which i probably will, and run it off a 9v battery then running 3 parallel sets of 4LEDs in series i would need to have 3 '22ohm' resistors in parrallel.
thats if i've understood the diagram. look on the link i provided earlier as that can work out what resistors you need.
the maplins website actually list the specific details of the LEDs

I'm just working out how many i would need, to get upto 100W worth of power or more.
the ones i'm looking at
Click to expand...

That concerns me. If you really have put the three 22 ohm resistors in parallel you have made a 7 ohm resistor. This will triple the current draw and make things a bit warm.

What you should have is four LEDs in series followed by one 22 ohm resistor, three times. Each 'stick' will have two wires to the rest of the world, one from the first LED anode and the other from the free end of the resistor. These wires should be joined together (like for like obviously), the LED wires to the battery Positive and the resistor wires to the Negative via the switch.

Edit: If you look carefully at the base of the LED you will see a small flat has been cast into it. This is beside the cathode terminal.
 
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That is indeed what I was describing.

BTW, I edited my post while you were posting to add this

Edit: If you look carefully at the base of the LED you will see a small flat has been cast into it. This is beside the cathode terminal.
 
They make things like this now and they have various sizes to fit a wide range of lenses, this one costs about £35.
 
I have a mate that is an electronics boffin he has made a diving torch for UW video using LEDs it took him ages to design and build the stabillised power supply. It and the expensive LEDs went phut a couple of times. It was I think at least 500W output though.
 
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