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Binghamton, NY
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I want to drive 4 of these LEDs http://www.rapidled.com/royal-blue-moonlight-led/
3.3V @350mA

I want to use PWM from the arduino for dimming.

It's going into a fixture with 3 other drivers form the ELN60 line (1X 48P, 2X 27P) http://www.meanwell.com/search/eln-60/ELN-60-spec.pdf

I chose the other 3 because they were recommended by the website I'm buying the LEDs from. I would guess I could use the ELN60-12P, Which is $24. Would be nice to keep the footprints consistent, so if this driver is a suitable option, I would prefer to use it. I'm just not completely confident in my knowledge, so I figured I should ask.

Also thought it might be possible to just drive them from the arduino its self? I don't know.

EDIT: I'll keep looking, but I guess I just don't know how to look at the spec sheet to see what I need. I have 4X 3.3V@350mA, so I need 13.2V @ 350mA, right? There are two sections on the spec sheet that talk about voltage output; LED Operation Voltage, and Voltage ADJ Range. Could someone explain these further? My 13.2V lands within LED Operation Voltage on the ELN-60-12P, but in Voltage Adjustment range of the ELN-60-15P

« Last Edit: April 10, 2013, 11:43:51 am by Longarms » Logged

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Eugene, Oregon
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That will be too much current for any arduino, you will need an external power supply.

You will also probably want some transistors, and resistors. Assuming you want to turn them all on and off at the same time, and not individually, you could use one big transistor, and one big current limiting transistor (and probably another  couple resistors on the transistor.)

If you try to hook even one of those up to your arduino, and run it at full current, it will most likely damage or break it.
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Binghamton, NY
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I think I might have not worded my original post well enough. The arduino is only used to engage the dimming function of the drivers, using PWM.



My question is; to power 4X LEDs 3.3V@350mA, which driver should I use.

I had a side question, asking if the arduino could supply power to this string, instead of using a driver, and maybe that's what you're referring to. I assume that's not possible, but figured I would ask.
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Eugene, Oregon
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If you want to power Four 3.3v 350mA LEDs, you will need about 1.4 amps (350 x 4 = 1,400) at 3.3v, or you could run them in series at 13.4v at 350mA. Either way should work, but parallel is probably the better way to do.

I dont know any of those products listed, so I cant really advise you on that.

There are many different arduinos out there, some can handle quite a bit of power (like the mega), but Im pretty sure that none will do 1.4A. They do have 3.3v and 5v power sources, but not enough current to run those LEDs directly.
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Valencia, Spain
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My question is; to power 4X LEDs 3.3V@350mA, which driver should I use.

4 x 3.3 = 13.2

The  ELN-60-15 can output that many volts, so that's the one to go for. Get the "P" model for PWM control.

nb. You have to open it up and adjust the output current to 350mA before you can use it. I assume you connect up a multimeter on the 10A range and twiddle the knob until it says 0.350
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Valencia, Spain
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If you want to power Four 3.3v 350mA LEDs, you will need about 1.4 amps (350 x 4 = 1,400) at 3.3v, or you could run them in series at 13.4v at 350mA. Either way should work, but parallel is probably the better way to do.

Rubbish. Connecting LEDs in parallel is a BAD idea, especially power LEDs.
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Binghamton, NY
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I was leaning towards the 15P, thanks for the confirmation.

Any insight into what the "Voltage Adjustment Range" spec on the datasheet means? It's in the same table as the "LED Operation Voltage"

On the 15P, VAR is 13.5~16.5 (This was my only concern, as this is above the 13.2V the LEDs will take.)

I just got the bright idea to email Meanwell customer service. I'm betting on the 15P, but I'll report back either way.

Thanks for all the replies!

EDIT: BONUS ROUND! I dono how electricity works; do I need to adjust the voltage the driver provides, or will the LEDs only suck out as much voltage as they need? (There are both voltage and current trim pots in the driver)
« Last Edit: April 11, 2013, 01:22:15 pm by Longarms » Logged

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Valencia, Spain
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I was leaning towards the 15P, thanks for the confirmation.

Any insight into what the "Voltage Adjustment Range" spec on the datasheet means? It's in the same table as the "LED Operation Voltage"

It has a voltage adjustment knob, you need to set it above the minimum needed.
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Binghamton, NY
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So, for my case, I can turn it all the way down. Thanks for the help!
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