? on Meanwell drivers for LED's - Im baffled here!

[khanb31]

Hey hey RC,

Well, Im trying to make myself an LED fixture for my new tank. I went out and purchased 4 of the Meanwell ELN 60-48D drivers.

Ive got to be missing something here because im COMPLETELY baffled with what im finding.

My Drivers (which as far as I understood) are supposed to be putting out around 48 Volts with a 120V AC input from my walls.

Can anyone tell me why im only getting a max of ~28 volts output?

Ive tried all 4 drivers and each one gives me the same results. They have ELN 60-48D written ALL over them (except for the circuit board). They have all be adjusted with the internal potentiometers and each return the SAME results. 18-28 volts through its full range. The setup is simple, hooked up the input line with a cord to my standard 120V ac wall outlet, and ive got my voltmeter on the output.

Anyone able to give me some comfort here? im not happy with how this is going.......

Thanks,

Jim

 

[stugray]

Have you hooked up anything to the Dim wires?

You need to apply 0-10 Volts DC to those lines.

10V = 100%

0V= 0%

If you just leave them floating, you caould have anywhere in between.

AND turn them drivers WAY down before experimenting or you will be ordering more LEDs very soon.

Stu

 

[khanb31]

ah ha.

That is one of two things I was thinking could happen.

1- Dimming wires need to be properly driven.

2- They sent me the wrong drivers!

Well, other than getting the profilux controller that I want.......how can I easily get this dimming line taken care of?

I guess I could follow this build.
http://reefcentral.com/forums/showthread.php?t=1662682

He has a link to some smaller pots that could work.

 

[stugray]

"how can I easily get this dimming line taken care of"

Get a 12VDC "wall wart" Get a large potentiometer ( variable resistor with a knob ).

It can be anywhere from 1000 Ohms to 100,000 ohms ( 1K to 100K ).

Hook the high side of the Pot ( either end ) to +12VDC.
Hook the low side of the Pot ( opposite end from above ) to 12V RTN/GND.
Also hook this line ( 12V RTN/GND ) to the Dim- line ( White on the Meanwell )

NOW take the "wiper" of the Pot ( this is the part that adjusts ) and hook it to the Dim+ line of the Meanwell ( Blue )

Remember to turn down the internal current adjust before trying it and you need to know how to measure the current through the LED string to adjust. I use a DMM in current mode & I adjust my max current to 700mA.

Then you can experiment with the Dim knob (CAREFULLY) until the max on the knob corresponds to the max current through the LED string.

The spec sheet of the Meanwell does not state the absolute maximum voltage that can be applied to the Dim+ Pin, so I would advise you to not just "turn it all the way up" with the above design as you could apply 12VDC to the Dim+ pin.

My guess is that it wont care, but I wont guarantee it.


Stu

 

[khanb31]

Thankya so kindly Stugray!

 

[g8gxp]

just from what i observed when testing them. You can use a 9v battery hookup just for testing purposes to make sure you are getting full output. However this will be at full duty cycle, so make sure you have enough LED's on the string to take full load (i had 13 per string). Otherwise you'll fry a bunch of LED's instantly. Guess how I know this?

 

[JaredWaites]

So Stu which internal pot do you turn? There are two I do believe.

- Jared

 

[g8gxp]

I forget the numbering but the one that is under the steel casing is Voltage and the one on the outside (at the edge of the driver) is Current. If you go to the Meanwell page I think there is a blueprint somewhere of their ELN series that shows everything.

 

[der_wille_zur_macht]

And to further clarify, you want to fiddle with the current pot, not the voltage pot. Safest bet is to turn it all the way down, wire the fixture, turn it on, and use a multimeter to turn it up to the desired current.

That procedure should be used to set the max output - do all that separately from dimming control - i.e. with your dimming circuit on 100%.

 

[chriscobb]

I'm alittle confused on the Meanwell drivers...I was looking on a site and it has the ELN-60-48P as the dimmable driver. I was under the impression that the ELN-60-48D was the dimmable. Any clarification on this area?

 

[hllywd]

They're both dimmable. The "D" uses 0 - 10VDC as the variable signal. The "P" needs a PWM.
Tim

 

[L98-Z]

just from what i observed when testing them. You can use a 9v battery hookup just for testing purposes to make sure you are getting full output. However this will be at full duty cycle, so make sure you have enough LED's on the string to take full load (i had 13 per string). Otherwise you'll fry a bunch of LED's instantly. Guess how I know this?

hmm... you fried the LEDs by using less than 13?

It's been awhile since I've played with diodes, but once they reach their voltage limit, they act like an closed circuit. So it shouldn't matter if it's 1 LED, 5 LEDs, or 13 LEDs. What am I missing here?

 

[monopolyman]

I'm alittle confused on the Meanwell drivers...I was looking on a site and it has the ELN-60-48P as the dimmable driver. I was under the impression that the ELN-60-48D was the dimmable. Any clarification on this area?

Unless your going to need to control the leds with arduino I wouldn't bother with the P version. The circuit required to dim the D version is 10x easier to build than the P version.

 

[der_wille_zur_macht]

What am I missing here?

It's easy to kill any LED by putting too much current through it. In a constant current driver, the feedback to the IC is current, and the control mechanism is altering the voltage - the IC can't directly alter the current, so it alters the voltage to achieve a target current. If the LED string's forward voltage is out of the range that the driver can create, you're either going to underdrive the LEDs or fry them. Depending on which meanwell datasheet you look at, this cutoff point is either low enough for one LED to be safe, or for any fewer than 6 to be dangerous. And there are conflicting results from people's own experiences blowing LEDs so it's hard to say.

Beyond matching the LED count to the voltage range the driver can generate, any constant current driver can be dangerous - for instance, most of them will go to "full on" if you run them with an open output circuit. If you then connect an LED array, the LEDs may all insta-fry, since the controller might not have enough time to pull the output voltage down to the correct level for your string.

That said, the 60w meanwell drivers are especially "dangerous" because their current range extends beyond what most of these LEDs can handle (all the way up to 1.3A) so it's easy to fry even a "correct" string.

 

[L98-Z]

It's easy to kill any LED by putting too much current through it.

Agreed there. I've done it many times. I even plugged AC directly into a small 20mA LED once. That made quite a little pop.

In a constant current driver, the feedback to the IC is current, and the control mechanism is altering the voltage - the IC can't directly alter the current, so it alters the voltage to achieve a target current. If the LED string's forward voltage is out of the range that the driver can create, you're either going to underdrive the LEDs or fry them. Depending on which meanwell datasheet you look at, this cutoff point is either low enough for one LED to be safe, or for any fewer than 6 to be dangerous. And there are conflicting results from people's own experiences blowing LEDs so it's hard to say.

I'm not sure I understand this exactly. It's you've built a proper constant current device, it should matter. That's the entire purpose behind the constant current device. Atleast that's my experience. The idea is typically that one or more LEDs could blow, yet the current being driven to each LED remains the same. Perhaps we're talking about different things?

Beyond matching the LED count to the voltage range the driver can generate, any constant current driver can be dangerous - for instance, most of them will go to "full on" if you run them with an open output circuit. If you then connect an LED array, the LEDs may all insta-fry, since the controller might not have enough time to pull the output voltage down to the correct level for your string.

I understand that now. Which I think people have found out the hard way on here correct?

That said, the 60w meanwell drivers are especially "dangerous" because their current range extends beyond what most of these LEDs can handle (all the way up to 1.3A) so it's easy to fry even a "correct" string.

I was under the assumption that these LEDs were capable of handeling 1.3A, but greatly reduces their lifespan. I had thought I read that somewhere. 700mA increase lifespan, 1.0A norm, 1.3A reduced lifespan. Not sure where I read that though, or even what LED. So who knows.

 

[der_wille_zur_macht]

I'm not sure I understand this exactly. It's you've built a proper constant current device, it should matter. That's the entire purpose behind the constant current device. Atleast that's my experience. The idea is typically that one or more LEDs could blow, yet the current being driven to each LED remains the same. Perhaps we're talking about different things?

Maybe we are just using incompatible terminology - but, it is definitely true that any constant current driver you'll use - DIY or off the shelf - will have a limited voltage range over which it's actually able to guarantee a constant current. This depends a bit on the topology of the driver used (buck and boost drivers hit hard walls above or below the PS voltage, for instance) and of course on the physical limitations of the circuit itself. Any time you're outside that range, all bets are off. Typically, if you fall below that range, you'll overdrive the LEDs, and if you go above it, you'll underdrive them (or roast the driver).

I was under the assumption that these LEDs were capable of handeling 1.3A, but greatly reduces their lifespan. I had thought I read that somewhere. 700mA increase lifespan, 1.0A norm, 1.3A reduced lifespan. Not sure where I read that though, or even what LED. So who knows.

You need to quote the datasheets word-for-word for each LED, since it's spelled out slightly differently for the different LEDs we're using. For instance, the XR-E datasheet contains this phrase "Maximum drive current: up to 1000 mA."

Plus, it's probably likely that some of the LEDs will operate outside their specified max current, though it's not something you'd want to trust. I have overdriven (i.e. driven above the datasheet-spec'd-max) some of the LEDs people use without blowing them, while other times I overdrove similar LEDs by about the same amount, they blew instantly. So there are definitely a lot of factors involved.

 

[L98-Z]

Maybe we are just using incompatible terminology - but, it is definitely true that any constant current driver you'll use - DIY or off the shelf - will have a limited voltage range over which it's actually able to guarantee a constant current. This depends a bit on the topology of the driver used (buck and boost drivers hit hard walls above or below the PS voltage, for instance) and of course on the physical limitations of the circuit itself. Any time you're outside that range, all bets are off. Typically, if you fall below that range, you'll overdrive the LEDs, and if you go above it, you'll underdrive them (or roast the driver).

Ahhhh, that's a good point. I didn't think about that. I see what you're saying. I've built buck and boost converters before, but that was in one of my graduate classes which has been some time. I didn't think about that.

You need to quote the datasheets word-for-word for each LED, since it's spelled out slightly differently for the different LEDs we're using. For instance, the XR-E datasheet contains this phrase "Maximum drive current: up to 1000 mA."

Plus, it's probably likely that some of the LEDs will operate outside their specified max current, though it's not something you'd want to trust. I have overdriven (i.e. driven above the datasheet-spec'd-max) some of the LEDs people use without blowing them, while other times I overdrove similar LEDs by about the same amount, they blew instantly. So there are definitely a lot of factors involved.

True. I didn't look at the datasheets, it was just a statement I read somewhere. I didn't plan to overdrive the LEDs at all.

 

[nowlan]

Did you get this sorted yet?

ve tried all 4 drivers and each one gives me the same results. They have ELN 60-48D written ALL over them (except for the circuit board)

What marking were on the board? or there isnt.


When I got mine, we had a benchtop power supply, and put 10v dc on Dim+.
Fastest way is to ues a 9v to make 100% duty.

My friend didnt realize it was PWM, and treated it as D model.
Im sure it doesnt like it, but behaves similar.

nb: if the voltage is lower, the output will drop too.
My 9v battery die after 1-2 weeks. You see the light is less as DC volts sag.

You want to adjust SVR2. Read the datasheet.
Turn off at the wall, make changes, measure on DMM. (repeat).
Start with it turned all the way down. Aim for 950ma or less for margin of safety.

Forget what we loaded output up with.