LED MeanWell power supply?

[spark]

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.

 

Do you know many amps can the the 'D' and 'P' models take for the dimming?

 

 

Also, for the 'P' model, the signal has to be 3kHz or less or it will not recognize it.

[redfishsc]

That I don't know for sure. I think I read in the thread somewhere that the D model drew 3mA, which isn't much. I'm pretty sure any of the power supplies we have available to us will work fine, but don't take that as gospel.

[spark]

That I don't know for sure. I think I read in the thread somewhere that the D model drew 3mA, which isn't much. I'm pretty sure any of the power supplies we have available to us will work fine, but don't take that as gospel.

Thanks. I will call Meanwell and ask. There are bunches of controllers boards that can take a PWM 0-5V input and out put a predefined 0-10V PWM output at a dip set frequency like 300 Hz or 3kHz which would work with the P models. However, they produce 5-15 amps. These are $15 boards that could be a plug and play option.

 

I am continuing with my op amp design to see how it works. Waiting on my rail to rail & high speed op amps to arrive.... In retrospect, I wish I would have ordered the D models as it is pretty simple to take a pwm input and output a linear 0-10V analog signal. I have had issues with getting good linear results taking the pwm input and getting a good linear output that is still pwm without having to regenerate the pwm signal. (I unfortuntately do not have an oscilator)

 

Depending on the test with the rail to rail op amps go, I may end up having to run through a comparator to regenerate the pwm (for those of us using the "P" models.)

[redfishsc]

I was reading the data sheet on the ELN60-48 and wondering about the SRV1. Could this be turned up so to allow an additional LED, making this driver capable of 14 XRE's?

 

Supposedly if you max the SRV1 out, the max output voltage would be 52.8. 14 XRE's should require around 51.8.

 

Is this plausible?

[evilc66]

In constant current mode, the voltage changes based on the LED requirements. SVR1 won't do a thing for you. 14 LEDs is possible based on the datasheet, but 13 is what I would consider the safe limit.

[spark]

I just got to test my op amp circuit and the result are perfect. I am a happy man.

 

I tested two op amps to see how I could linearly increase and decrease the 0-5V arduino pwm signal doubling the voltage 0-10V. So I wrote a real simple program that goes from 0-5V then steps back down in a loop for testing with the Arduino.

 

Results

TLC084: A near rail to rail high speed (10MHz) op amp steps up and down between .2V up to 8.9V

TLV274: True rail to rail op amp (3MHz) steps from 0-10.05V perfectly up and down doubling the voltage.

 

Been running the program with the multimeter hooked up for about 1 hour with consistant results. So FINALLY success.

 

So here is the plan:

 

I ordered some of these boards that are generic pre-fab pcb boards for $10 each.

 

http://www.muzique.com/tech/op-amp.htm

The nicething about these boards is there is plenty of space for a lot of resistors and capacitors, but if you don't need them, you just do not put anything on the board and it work great. So no jacking around with prototype board an trying to make runs with solder. Just pop in the resistors and capacitors where needed and a quick solder job and done. The entire circuit will cost about $16.

 

I just need to order the dual version of the TLV274. The first stage will be a low pass filter that will only allow frequencies up to 3KHz (the max the 0-10V meanwell pwm can see) then run it into the second op amp on the IC op amp and give it the voltage doubling. ( I am pretty sure I can do both in one pass with one op amp, but this is a little easier and since I know each works individually, I do not want to do another 2 week stint figuring out the single op amp circuit that does both.)

 

I will post the schematics for the circuit for everyone, but I have to go because it is my youngest daughters birthday party today.

 

Basically these are the parts:

 

Low pass filter:

2- 10k ohm resistors 1%

1- 4.7 nF capacitor 2%

1 - 6.8 nF capacitor 2%

 

With the tolerances, the cut off frequency will be between 2732.7 Hz and 2901.7 Hz for maximums which falls within the spec range for the meanwell pwm (0-3KHz).

 

Voltage Doubler:

2 - 10k ohm resistors 1%

1 - 4.02K resistor 1%

1 - .1 uf capacitor 3%

 

1 - TLV272 RTR dual op amp

 

more to come...

[Gomer]

Ok, here is something I made to aid in clarification for those trying to make the pwm circuit for the "P" models.

 

 

Black lines are component leads

Red lines are bottom side solder traces

Blue lines are top side wires

 

Use a 12v or greater (up to 32v) power supply for this.

 

Is there an easy way to change this to run with 10V?

[evilc66]

Sure. Take the LM317 and the two supporting resistors out and connect 10v to pin 8 on the 555.

 

Where have you been lately? Haven't seen you hovering around here for a long time.

[Gomer]

Sure. Take the LM317 and the two supporting resistors out and connect 10v to pin 8 on the 555.

 

Where have you been lately? Haven't seen you hovering around here for a long time.

 

 

so just remove the LM317, the 1.5k Ohm and right 10K ohm.

thanks

 

I'll see how that works for me (or wait till you get a chance for the 0-10V-->PWM circuit figured out. Have "P" drivers as that was what was available at the time and have 0-10V on the APEX)

 

'I've been a little busy and haven't been posting here much (been reading though). I'll have an array going soon using 18white and 18 RBlue driven by the ELN-60-48-P at 1amp (-25%). I'll post up when I get it rolling

[evilc66]

Good deal man. I enjoyed our discussions in the early days of LEDs here on NR. It's changed a bit hasn't it?

[Gomer]

yup back then, only 3-4 of us dared touch the subject. Now it is embraced with open arms! Very cool stuff.

[cptbjorn]

I wouldn't put a low pass filter on a square wave like that, all it will do is round off the corners depending on the pwm frequency and slope+frequency of the filter.

 

I'm sure the Meanwell datasheet means a 0-3khz square wave, and if you run a 3khz square wave through a 3khz low pass filter you don't have a square wave anymore.

[spark]

That is true. It may work just fine without the low pass filter. I think the pwm from the Arduino is about 400Hz. Leaving out the filter will keep it a square wave, I am just not sure how consistant the freqency would be on the output. I don't have an osciliscope to use for testing.

 

The only way I know of doing that with an op amp is to use it as a comparator to produce the pwm, which is not difficult to do. I am open to any ideas or suggestions...

 

It may be a three pass op amp circuit that would work the best. Low pass filter to voltage doubler to the comparator to produce a pwm wave...

 

The LM555 uses two internal op amp comparators and two internal transistors. It can also be used with the pcb I have.

[Gomer]

Has anyone figured out the circuitry change to convert an ELN-60-48P into ELN-60-48D? I am sitting on three P's and really wish I got the D's (ignorance isn't bliss )

[nanotuners.com]

Gomer - we have the Ds coming back in late this month (Dec 29). Lmk if you want me to hold a few for you.

[Gomer]

Gomer - we have the Ds coming back in late this month (Dec 29). Lmk if you want me to hold a few for you.

 

I wouldn't mind the D's but I unfortunately am sitting on 3 brand new Ps right now

 

Let me see if I can sell them off or something lol.

[spark]

That is true. It may work just fine without the low pass filter. I think the pwm from the Arduino is about 400Hz. Leaving out the filter will keep it a square wave, I am just not sure how consistant the freqency would be on the output. I don't have an osciliscope to use for testing.

 

The only way I know of doing that with an op amp is to use it as a comparator to produce the pwm, which is not difficult to do. I am open to any ideas or suggestions...

 

It may be a three pass op amp circuit that would work the best. Low pass filter to voltage doubler to the comparator to produce a pwm wave...

 

The LM555 uses two internal op amp comparators and two internal transistors. It can also be used with the pcb I have.

 

Just verified from the guys on allaboutcircuits forum that the op amp will not change the frequency at all. But the op amp generally will produce more of a triangle wave rather than a square wave, but should still work. The op amp has to be run open loop. Still a digital signal.

 

However, thanks to Sgt. Wookie on the forum, I have a circuit drawing similiar to what Evil had suggested a while back. He thinks the easiest solution for still using the PIC would be to use a logic level MOSFET or a transistor on your PWM I/O pin. It apparently will would invert the logic, so that 99% ON would be 99% OFF, but that can easily be changed that programming on the Arduino.

 

1 transistor, two 1/4W 1k resistors, and a 10v Zener diode.

 

 

I am unfortunately at my in-laws this weekend and cannot build them, but will when I get home and test both to see which works the best. I think both wil probably work fine. This was info I needed to get moving on this. I hope finally put the entire led hood together over Christmas weekend and get it over the tank.

[Gomer]

I would think yes, but I wanted to check.

With the ELN drivers, can you have a common ground on the driver side (black wire)?

 

I have a 4 conductor cable that I want to use for 3 drivers.

[smorrow5773]

Has anyone succesfully built the pwm circuit for dimming? I have now built 2 different versions 4 different times and cannot get the pot to change the brightness??

[lobophyllia]

In doing investigations on how to upgrade the lighting on my BC29, this thread and others have been invaluable. Thanks a ton to all of the guys who contributed thought and analysis to developing various solutions. Plenty of wall imprints on a lot of foreheads I'm sure, but that's the cost of trailblazing! Just wanted to express my appreciation.

 

I'm still totally up in the air about what direction I'll go, but am leaning towards an Arduino controlling either version of the Meanwell. I'm going to try an Arduino program that will vary the dimming signal over the course of an hour or two, either brightening or dimming in the morning and evening respectively. Hopefully I can put this all in one enclosure with an extension on the USB cable so that I can just plug into the USB/Serial of the Arduino from the outside and have the inside clean for air flow (maybe a small fan driven by the same AC adapter that will power the Arduino... just thoughts right now. Anyone else have the same sort of thing in mind?

 

Clearly the P and D solutions differ, but people seem to have success either way- which has proven easier or more cost effective seeing as I am parting this out from the ground up? I've read some amount of "whoops I should have got the 'D' version"...

 

 

 

On a somewhat unrelated note, my dad is a machinist so I'm going to try and design a custom heatsink and maximize my surface area within the stock hood, then have him fabricate it. Should be able to add a mirror polish on the bottom (to reflect any possible wasted light) and have everything professionally cut/tapped. I might have to buy him a six pack or something, but that's good savings.

 

I'll be back as I revise plans! Not sure when I'll pull the trigger on this budget-wise. I am curious about the other solutions that are out there, from open-top to all-inclusive hood specific DIY kits, but the hands-on in me wants to figure this out from scratch, do all the math, and see it come together.

[NewBostonConst]

Has anyone succesfully built the pwm circuit for dimming? I have now built 2 different versions 4 different times and cannot get the pot to change the brightness??

 

If you have an radio controlled car or plane you can use the radio as a test. The control signal for the servos are PWM. I haven't looked up the spec's of the signal but I think it will work. I also build robots with high school students and we use PWM type signals to control speed contollers on the robot. There are many micro processors that have pwm outputs also. BASIC Stamp from Parallax is one of them that they are extremely cheap, easy to hookup and the program is free.

 

Parallax Processors

 

I don't know if this is over your head but this one is $30 plus some assesories need at the bottom of the page.

 

Basic Stamp 1

 

You might want to call them....You are used alot in colleges now for teaching and there is alot of free programming examples. I have been working with some of my old robotics students that are now in college with these.

[spark]

If you have an radio controlled car or plane you can use the radio as a test. The control signal for the servos are PWM. I haven't looked up the spec's of the signal but I think it will work. I also build robots with high school students and we use PWM type signals to control speed contollers on the robot. There are many micro processors that have pwm outputs also. BASIC Stamp from Parallax is one of them that they are extremely cheap, easy to hookup and the program is free.

 

Parallax Processors

 

I don't know if this is over your head but this one is $30 plus some assesories need at the bottom of the page.

 

Basic Stamp 1

 

You might want to call them....You are used alot in colleges now for teaching and there is alot of free programming examples. I have been working with some of my old robotics students that are now in college with these.

 

 

The issues with these for a meanwell "P" is that the frequency on PWM for servos is normally pretty high. The meanwell will only take a PWM 100-3Khz. It will not see the signal if above the 3Khz. Servos require a much higher freqency.

[Gomer]

Just a little FYI.

 

The -25% setting for 1 amp by turning SVR2 all the way counter clockwise does not set to 1 amp. It set to ~250mA.

[M@rine_lover]

Just a little FYI.

 

The -25% setting for 1 amp by turning SVR2 all the way counter clockwise does not set to 1 amp. It set to ~250mA.

 

I thought -25% of 1.3A is equal to 975mA assume you are referring to ELN-60-48 !

 

BTW, How do you measure and what formula do you used to come out the conclusion of ~250mA instead of 1mA ?

[Gomer]

I thought -25% of 1.3A is equal to 975mA assume you are referring to ELN-60-48 !

 

BTW, How do you measure and what formula do you used to come out the conclusion of ~250mA instead of 1mA ?

 

yes, -25% of 1.3 is 0.975 amps. I thought 1amp was a good approximation

 

No formula. I measured the current out of the ELN-60-48 through 12 XR-Es with a multimeter.