The 'Evil Cluster' revisited

[farkwar]

The 2200 pulls an average of 37v at 700mA, so that driver most likely won't work. If looking for a plug n play like the Inventronics, you'd need to use the 75w driver, but you could run two from that.

 

What size tank do you have? I've got PAR numbers in my evil cluster thread using the 1350-B, and judging by those, I doubt you'd ever need the 2200.

I have an Elos Midi on order. 36 gallon cube.

 

That power supply puts out 36v, the test spec shows the LED at 37v at 700ma. What am I missing?

 

It's my understanding that efficiency decreases at full power, thus more efficient at half power. Which I was hoping to do.

 

The 75watt power supply is too expensive($76), at this point. I might as well switch over to the separate 48v power supply plus LLD if I'm going to invest that much for power?

Wouldn't a Meanwell 60-48 (1.3A) run two in parallel, they are like $35.

[Steensj2004]

Well, I've been looking for the smile emoticon where the little smiley shakes for a bit, then his head explodes. Kinda how I feel reading and trying to understand all this. Heck, I barely have my feet wet in LEDs but need help,haha. So I will stick with this one rocking back and forth because my brain is melting,lol. Here is the deal, I have 650.00 to spend on a fixture..... If I cant find out an attractive LED scrap build for that cost, to put over top my 40 breeder I am ordering a Radion Gen2 this weekend. So all you LED wizards....I have been told I can build a fixture that will blow the Led-sticles off a Radion for 650.00. Is this true? Guideance please?

[jedimasterben]

I priced a large array for a 90g a couple of nights ago and it was just shy of $650.

[Paleoreef103]

Well, I've been looking for the smile emoticon where the little smiley shakes for a bit, then his head explodes. Kinda how I feel reading and trying to understand all this. Heck, I barely have my feet wet in LEDs but need help,haha. So I will stick with this one rocking back and forth because my brain is melting,lol. Here is the deal, I have 650.00 to spend on a fixture..... If I cant find out an attractive LED scrap build for that cost, to put over top my 40 breeder I am ordering a Radion Gen2 this weekend. So all you LED wizards....I have been told I can build a fixture that will blow the Led-sticles off a Radion for 650.00. Is this true? Guideance please?

2 BL 950s, 6 rebel Ms RB, 2-4 Rebel Deep Red (optional), 6 Rebel ES Blue, 2-4 Rebel Cyan, 12 Hyper Violets, 5 LDDs (5 700ma, you won't need 1000mA for a 40 breeder). 1 180W 48V 3.75A DC power supply. 1 24" Heat sink. 2 4" fans. Optics if you want to hang the light from well above the tank. You'll also need ways to attach the LEDs to the heat sink, a soldering iron, solder, and wires. All of that should run you under $400 for an epic light. Throw on some way to control the lights and it'll get even crazier.

 

I have an Elos Midi on order. 36 gallon cube.

 

That power supply puts out 36v, the test spec shows the LED at 37v at 700ma. What am I missing?

 

It's my understanding that efficiency decreases at full power, thus more efficient at half power. Which I was hoping to do.

 

The 75watt power supply is too expensive($76), at this point. I might as well switch over to the separate 48v power supply plus LLD if I'm going to invest that much for power?

Wouldn't a Meanwell 60-48 (1.3A) run two in parallel, they are like $35.

A 36V powersupply will not light an LED whose forward voltage is 37V. You need to have at least as much voltage coming from the power supply as the forward voltage of the LED string you're trying to light. Running it at 37V is not running the LED at full power without considering the amperage. Amps are the amount of power you're actually putting through the light. If you ran an LED that tops out at 1 A at 500mA you'd be running it at half power. You're better switching over to 48V Power supplies and LDDs if you're planning on running more LEDs than just the one. I'm not sure what you're getting at with the meanwells. Those drivers run a maximum forward voltage of 48V so a single meanwell would run one of those LEDs, but you'll have to dim the drivers down below the 1.3A or you'll burn your LEDs out.

[jedimasterben]

They mean parallel. An ELN-60-48D will run two in parallel at around 650mA each.

[farkwar]

They mean parallel. An ELN-60-48D will run two in parallel at around 650mA each.

Thank you for the clarification.

 

Do you know how many watts these MeanWells use?

 

Let's say running at the full 1.3 amps. I have been figuring my usage based on 3 watts per LED, but that can't be right because the MeanWells are inefficient and are giving off heat by doing what they are doing. A string of 12 LEDs, through a MeanWell, must be consuming more that 36 watts of power, correct?

 

 

Kinda nevermind, I found this amps to watts calculator. http://www.rapidtables.com/calc/electric/Amp_to_Watt_Calculator.htm

 

Which gives me 62.3 watts. But I don't think it accounts for entropy waste.

[farkwar]

A 36V powersupply will not light an LED whose forward voltage is 37V. You need to have at least as much voltage coming from the power supply as the forward voltage of the LED string you're trying to light.

 

I didn't know that was a minimum number.

 

From my experience, LEDs are pretty lenient or flexible on voltage requirements.

 

Thanks for the clarification.

[jedimasterben]

Thank you for the clarification.

 

Do you know how many watts these MeanWells use?

 

Let's say running at the full 1.3 amps. I have been figuring my usage based on 3 watts per LED, but that can't be right because the MeanWells are inefficient and are giving off heat by doing what they are doing. A string of 12 LEDs, through a MeanWell, must be consuming more that 36 watts of power, correct?

 

 

Kinda nevermind, I found this amps to watts calculator. http://www.rapidtables.com/calc/electric/Amp_to_Watt_Calculator.htm

 

Which gives me 62.3 watts. But I don't think it accounts for entropy waste.

DO NOT think of LEDs as a 'wattage' device or you'll wind up needing new equipment. LEDs run on a constant current but need a different forward voltage down to the individual LED. If you take that 25w BXRA 2200 and put two of them on a 50w driver that gives 48v at just over 1A, it won't light and will probably destroy something, the driver or the LEDs one, because two of those LEDs will want to pull 77v at that same 1A. The voltage that LEDs use is fairly constant, it only varies a bit, depending on the LED, but current is what you can change to just about anything up to the LEDs' maximum.

 

Keep in mind that very few '3w' LEDs actually use 3 watts of power, and only at certain currents (around 1000mA usually). The BXRA is not a normal LED, it has a very high forward voltage compared to a Cree or Rebel, but also has significantly higher output at the same current.

 

Think of it this way - a constant current driver gives just that, a constant current, let's say it is set to give 500mA. You have two LEDs on the string - one is the BXRA you picked, one is a Cree XT-E. Both LEDs will receive the same 500mA, but the LEDs will ask the driver for a different forward voltage for each. The BXRA will ask for 36v, the Cree will ask for around 2.8v, and since the driver is constant current (instead of constant voltage), it will have a voltage range that it can handle, and will adjust the voltage to exactly what the LEDs are asking for. If you turn the driver up to 700mA with the same LEDs, they will ask for slightly more voltage, and the driver will auto adjust to the new voltage.

[farkwar]

It has a different forward voltage because its just a bunch of little LEDs all wired up end to end, correct?

 

Think of it this way - a constant current driver gives just that, a constant current, let's say it is set to give 500mA

 

So what am I adjusting when I dial pot SRV2 inside the MeanWell, I assumed it was the amperage output? The other pot under the heatsink is to change voltage.

 

But I can feed a single LED different voltages and it will light up with 3v, 9v, or 12v for example. But the array is different because it is a bunch of single LEDs already wired in series inside the device, correct?

 

If I run the two arrays in parallel, I can't see how it will ask for 77v, there is only 48 to give. And just like all the 12v things in your car, they all use 12v because they are all in parallel with each other.

 

 

Keep in mind that very few '3w' LEDs actually use 3 watts of power, and only at certain currents (around 1000mA usually)

This question was not about by design. It was about energy usage. When I pulled the plug on my NC28 150w HQI my electric bill dropped $125 a month. I don't want to spend that on my next reef system.

 

I am factoring in the cost of the power supplies, or trying to. If each MeanWell is costing me 75w(not 36w) and I have 4 of them running, I'm eating as much if not more energy as the 150W HQI(which is actually higher than 150 because the ballast was warm).

[farkwar]

it will have a voltage range that it can handle, and will adjust the voltage to exactly what the LEDs are asking for.

 

I don't understand this. When I meter it, it gives me 47.7 volts(48v close enough). I need a minimum of 8 LEDs and a maximum of 14, if I hook up only 8 the voltage will drop to 24v?

 

How does it know what my usage, from the LEDs, is?

[farkwar]

Oh, and thanks for all the help and schooling.

 

It is appreciated

[jedimasterben]

So what am I adjusting when I dial pot SRV2 inside the MeanWell, I assumed it was the amperage output? The other pot under the heatsink is to change voltage.

You're not doing jack to the voltage it outputs - you're changing the maximum voltage the driver will give before it quits. I did this on my ELN-60-48P running my Rebels to accommodate one more LED per string, but I only did that because I adjusted the maximum current down to 1000mA from 1300mA, otherwise I'd be running it slightly out of spec and would reduce the lifespan.

 

But I can feed a single LED different voltages and it will light up with 3v, 9v, or 12v for example. But the array is different because it is a bunch of single LEDs already wired in series inside the device, correct?

LEDs can work on constant voltage, which is why you can test small LEDs (like XT-E and Rebels) using two AA or AAA batteries in series, which would give 3v. You run any more voltage through it and you immediately destroy it. Try running a higher forward voltage chip like the BXRA at a lower voltage than it is rated for and it will not light, not up to a certain point. Voltage from a constant voltage power source (think your typical 12v power adapter) will determine how much amperage that a constant current device will get. I am still not 100% sure how it works from a constant voltage source, blasterman or evilc66 would be better to direct that question to. It gets hairy in a hurry when you're using constant voltage, though, so I don't recommend it.

 

If I run the two arrays in parallel, I can't see how it will ask for 77v, there is only 48 to give. And just like all the 12v things in your car, they all use 12v because they are all in parallel with each other.

In parallel, no, they would ask for their normal voltage, which is about 38.5v at 1A. It will vary slightly, and therefore the current to each one will vary by a little. If the voltages of each string were different, say if you had one Rebel on one side and one BXRA on the other, the current between the two strings would be wildly different.

 

This question was not about by design. It was about energy usage. When I pulled the plug on my NC28 150w HQI my electric bill dropped $125 a month. I don't want to spend that on my next reef system.

Bullshit. In California, the most you'll pay for electricity is around 22 cents per kWh, but let's do 25. Taking that figure, and that your 150w bulb probably pulled more like 200w depending on the ballast, and if you ran your light for 12 hours daily, that would cost you a little more than 60 cents per day, around $18 per month. Even if your home's A/C kicked on more than normal, even an old unit will keep up with it for very little more per day. Even if it cost the same as the electricity to run the light (it wouldn't), that's still less than $40 monthly.

 

I am factoring in the cost of the power supplies, or trying to. If each MeanWell is costing me 75w(not 36w) and I have 4 of them running, I'm eating as much if not more energy as the 150W HQI(which is actually higher than 150 because the ballast was warm).

The LED drivers will only pull slightly more than the LEDs are pulling. If you run a Meanwell ELN-60-48 to power a single BXRA 2200 at 1A, the LED will pull around 39w, and the power supply will be around 88% efficient, and should pull around 44w.

 

I don't understand this. When I meter it, it gives me 47.7 volts(48v close enough). I need a minimum of 8 LEDs and a maximum of 14, if I hook up only 8 the voltage will drop to 24v? How does it know what my usage, from the LEDs, is?

The LEDs 'ask' for a certain voltage. I'm not sure why you're measuring that many volts unless you have that many volts being pulled. You can check the power at the wall with a Kill-a-Watt unit to be sure, but the way they work is they deliver only as much power as is needed.

 

Oh, and thanks for all the help and schooling. It is appreciated

Is no problem, keeps me on my toes

[farkwar]

The LEDs 'ask' for a certain voltage. I'm not sure why you're measuring that many volts unless you have that many volts being pulled.

 

A meter doesn't 'ask' for a certain voltage. It just measures what it is.

 

Anyway, I think I'll just order some array LEDs up tomorrow and play around with them when they get to me. Need to get one of those kill a watt meters too.

 

And go from there.