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LED MeanWell power supply?


zingtaw

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Hello again, :)

 

Is there any risk in running 3 meanwell driver 1-10v dimming circuits in parallel?

 

My understanding is that there is a risk in running the actual LED's in parallel if preventative measures are not taken i.e. current mirror, however it has been raised in reply on the above posted profilux topic that this could also be a risk.

 

Re the limitation of the L-ports on the profilux the reply I got was:

 

...You have only to keep in mind that you don't draw more than approx. 10mA from one 1-10V-interface (check the datasheet of the LED-driver).

and then I had another helpful person provide this information:

These drivers run at 3.3ma at 10v.

3 of them should be the limit per channel.

So I appear to be ok on the Profilux front.

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I may be overcomlicating this, but I am going to try an Noninverting Ampliflier Op Amp solution for doubling my Arduino PWM from 5 to 10V to use the ELN-60 P. My only concern is if this will be jittery. With a low pass filter combined, should work on a "D" as well. A low pass filter will eliminate any jitters.

 

Anyway I am going to give it a try.

 

I think this can be accomplished with a LM741 op amp or what I am going to use is the TL082CP Op Amp.

 

So I am going to try these parts:

1 - TL082CP (these can be either single or double to run two off the same chip)

 

3X10K .1% tolerance resistors (these are pretty precise so the .1% tolerance is a good price/performance - any lower and you are looking at $7-8 resistors which is pricey) so with .1% tolerance, worse case, you could hit 10V on the high end and 9.5 on the low end as you will never go higher than the Op Amp Voltage source.

 

Here is the Op Amp calculator link that also shows the schematic. Use 5V on the Rs input and 10K all around on the resistors. ( you could do 22/22/10K to get the same result, but your voltage for the Op Amp would have to 12V and not 10V )

 

There really should be a couple lines on the Op Amp showing the pos & neg power source for the Op Amp, but seldom are put in the drawing.

 

Op Amp Circuit link

 

Like to get feedback on this. Any thoughts?? Am I way off base...

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I was finishing up a 10 led pico light when i had some issues with my meanwell 60Ds. I have two Meanwells each running 5 Cree 3w leds one for white and the other for blue. I tested my led strings as I soldered them up and everything was working great until I mounted everything on the heat sink. Once they were on the heat sink and fired them up they flashed real quick and they were all toast. So I narrowed it down to two possible variables which could have caused the failure. 1) My soldering job could have had shorts in it which became an issue when i mounted it to the heat sink. OR 2) When I was plugging it all in, I plugged in the meanwells in before plugging in the transformer for the dimming circuit.

 

So i guess my question is whether or not energizing the meanwell with no dimming voltage could burn up a string of leds?

 

Thanks in advance for the help!

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1. Most likely

 

2. Not likely.

Thanks Evilc66, yeah after thinking about it seemed highly unlikely for the dimming circuit being at 0v at startup causing any issue.

 

This is off topic for the thread thread, but what is usually the problem with or solution for LEDs that are shorted when metered but show no visible connection to the back plate of the star?

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Have you tested each led? I just used 2AA batteries and soldered wires on the ends and tested each led after it was wired. Pos wire to the + pad on the led and the Neg to the heatsink. If it lights up you have a short. If it didnt turn on when you touched the heatsink place the Neg wire one the - pad and see if it lights up. If it doesnt, they are toast.

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Have you tested each led? I just used 2AA batteries and soldered wires on the ends and tested each led after it was wired. Pos wire to the + pad on the led and the Neg to the heatsink. If it lights up you have a short. If it didnt turn on when you touched the heatsink place the Neg wire one the - pad and see if it lights up. If it doesnt, they are toast.

I really don't want to hijack this great thread on Meanwells with my inability to successfully solder some LEDs together. Yeah moovinfast I did check them and it appears I fried the whole array. I have built a good number of electronics projects more sophisticated than this so its frustrating to have botched this one up. I guess I underestimated the issues of building LED fixture. :huh:

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That's one approach. You could also use a boost inverter too for a little more powerful and cleaner output.

 

Okay so my first try on the op amp method did not work well. It works fine when there is a constant 5V pwm feed from the arduino. I get a steady 10V output (double). But when I fed a pwm signal from the arduino that was fading in and out, results were sporadic and all over the place. I think my issue is that the op amps I tried (lm741, tl082 and the lm324) are not Rail-to-Rail and significantly less accurate. So when the voltage goes up or down, only a RTR op amp can linearly handle the fluctuations correctly. Non RTR can only hit within 1.5 volts at best. I am going to try the LMV358, which is a quad op amp which is RTR version of the LM324.

 

I am also going to make a simple transistor boost to see how that compares to the op amp. I will use a PNP transistor but with a voltage regulator (LM8910) which will give a fixed 10V source. I will see which works the best.

 

Spark Fun Op Amp

 

I also found these at Spark Fun: It is a RTR LMV358 op amp circuit that has possibilities for the "D" version with (or without) an Arduino. From the schematics, it looks like it runs through two op amps with all 10K resistors and should double the voltage (is adjustable on the circuit with a trim pot), runs through a low pass filter to smooth out the signal to a true analog signal and then the second amp will boost the voltage. Has good potential for people with the “D” meanwell, but since the capacitors filter into a much higher frequency analog signal, not so great for the” P” version. The only thing I am not 100% sure of is the frequency of the analog output (which is set at 15.9kHz ). It should work, but I could not find anything in the ELN .pdf besides the pwm 0-10v has to be below 3kHz. Nothing for the “D” 0-10V. But at a higher frequency, the signal should be very clean for analog. (could also poss. also switch the caps to lower the frequency if needed.) SparkFun might even switch those out to meet specs…

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EXTREMELY IMPORTANT INFORMATION:

 

The Meanwell ELN-60-48 has a limitation that I had not noticed before, that seems to be causing some people some headaches. It will require a minimum of 6 LEDs connected to regulate properly. I know I have said that one LED should be fine for testing, but it seems that this is a recipe for disaster. I know this message is a little late for some, but for those looking to use these, please pay attention to this.

 

Sorry for any inconvenience that this has caused people.

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EXTREMELY IMPORTANT INFORMATION:

 

The Meanwell ELN-60-48 has a limitation that I had not noticed before, that seems to be causing some people some headaches. It will require a minimum of 6 LEDs connected to regulate properly. I know I have said that one LED should be fine for testing, but it seems that this is a recipe for disaster. I know this message is a little late for some, but for those looking to use these, please pay attention to this.

 

Sorry for any inconvenience that this has caused people.

 

Thanks for the info! I wish I had read this an hour after you posted it because I spent another Saturday cooking LEDs. This time I used Teflon insulated wire to minimized the issues of melting the insulation and causing shorts to the star. Then I spent 30 min poking and prodding the whole built with my DMM to check for any shorts, and also tested each LED separately for function. After all that fun I hooked my two meanwells up to the 5 LED strings. One of my meanwells did just fine the other was blinking the blue string intermittently every ~ 6 sec for ~1/2 sec. First I thought there was an issue with my blue string wiring so I flipped the power supplies and it flashed the same was with the whites. So I started poking around and checking everything and no red flags came up. I then went to check the current out of the supply on more time and hooked it to the LED string instead of a dummy load and at that time the meanwell decided to cook the string for good. I putting these on the shelf for a bigger build in the future and I am going to order some buckpucks. Nanotuners made good money off me every week of this project as I beat my head into the wall with these meanwells. FML

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Sorry about the issues you are having with your build. Considering that I have not had issues with lighting up one and two LEDs on a driver, it was something that I overlooked. Sorry it had to come to you damaging some LEDs for me to actually look at it.

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As a side note, I sent an email to Meanwell about the dimmer's tolerance for excess voltage. He called me back today.

 

He stated pretty clearly that 10.6v is the maximum tolerance. Anything over that can be damaging.

 

10.6 is the max.

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Hey Evil, no sweat. I appreciate you hunting that info down and now I don't have to troubleshoot an issue that I probably would have just given up on. The weird thing is that one of the power supplies seemed fine with 5 LEDs the other did not and cooked the string. Weird... -_-

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As a side note, I sent an email to Meanwell about the dimmer's tolerance for excess voltage. He called me back today.

 

He stated pretty clearly that 10.6v is the maximum tolerance. Anything over that can be damaging.

 

10.6 is the max.

 

Hrm... if 10.6v is the max over voltage and the most you can turn them down via the SVR1 pot is ~41v then you would need a voltage drop of about 30v which would be more than 6 LEDs. With the Cree 3w having a forward voltage of 3.3v you would need 9 to be safe. Does that sound right?

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Hrm... if 10.6v is the max over voltage and the most you can turn them down via the SVR1 pot is ~41v then you would need a voltage drop of about 30v which would be more than 6 LEDs. With the Cree 3w having a forward voltage of 3.3v you would need 9 to be safe. Does that sound right?

You're talking about two different things. The 10.6V is referring to the dimmer circuit (0-10V), not the driving voltage for the LED's.

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Hey Evil, no sweat. I appreciate you hunting that info down and now I don't have to troubleshoot an issue that I probably would have just given up on. The weird thing is that one of the power supplies seemed fine with 5 LEDs the other did not and cooked the string. Weird... -_-

 

If I had to guess, the difference wasn't in the drivers, it was in the LED's. All you'd need is a single LED in one of the 5 that couldn't handle what the driver was putting out, and when it fried, you were down to 4-- . I don't know then if the voltage stacks up on them when you have too few like things happen when wired in parallel and one dies, though.

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In my experience LEDs really like to fail short. Are there any factors that contribute to whether or not they fail open or closed?

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