Your CXA3590 Mission Should you Choose to Accept It !

[Kuifje76]

The reason I ask is that you can only get high efficienty drivers with high voltage.
It seems a bit silly to me to get the highest bins and then use a cheap driver and loose lumen/watt through that driver
Will the situation above work ? can I connect 8 cobs on that driver ?

 

[SupraSPL]

Yep O&R nailed it. I am a absolute fool for doing this, but I work on live wires all the time, to save time. I am much more careful working on live 120V AC wires than live 12V DC wires, even though car batteries are capable of delivering massive amounts of current. I have been shocked dozens of times by 120V, but only once from 12V, for example.

Have you ever put a 9V on your tongue to see how much juice it has left? Weird sensation.

"The present method for electrocution in Florida is as follows:
2,300 volts, 9.5 amps, for 8 seconds;
1,000 volts, 4 amps for 22 seconds;
2,300 volts, 9.5 amps for 8 seconds.

Other states vary."

 

[Kuifje76]

Thanks for the explanation Supra, and how about max voltage, can one use a driver with max 286V and use 288V or is it a hard cap ?

 

[SupraSPL]

The Vf of the CXA3590s will vary and it will decrease as they warm up. But the HLG Mean Wells are strict about their upper Vf limit. If you go above it even slightly it will reduce the current very significantly. Since the current will be so low it could take a long time to warm them up so cutting it very close to the upper Vf range is not advised.

Yes it is true that the higher voltage HLG series create a more dangerous situation in terms of electrical risk as opposed to a ~40V circuit. There a things you can do, primarily covering every part of the circuit thoroughly and grounding your heatsinks. It also requires that you mind the voltage rating of the wire jacket on the DC side, which may be a significant inconvenience. The drivers have over voltage and short circuit protection so there are some built in safety precautions.

 

[Kuifje76]

The Vf of the CXA3590s will vary and it will decrease as they warm up. But the HLG Mean Wells are strict about their upper Vf limit. If you go above it even slightly it will reduce the current very significantly. Since the current will be so low it could take a long time to warm them up so cutting it very close to the upper Vf range is not advised.

Yes it is true that the higher voltage HLG series create a more dangerous situation in terms of electrical risk as opposed to a ~40V circuit. There a things you can do, primarily covering every part of the circuit thoroughly and grounding your heatsinks. It also requires that you mind the voltage rating of the wire jacket on the DC side, which may be a significant inconvenience. The drivers have over voltage and short circuit protection so there are some built in safety precautions.

Could you explain this sentence for me, i'm a total noob when it comes to electricity, but i'm learning

 

[SupraSPL]

Basic "hookup wire" is very affordable but it has a plastic jacket that is only rated for about 50V. TEW wire is more expensive but the jacket is rated for 600V. One of the most convenient wires for our designs is 18 awg CL2 security wire. It comes in 18/2 18/4 and 18/6 and other configurations, really smooths out the the wiring nest. Unfortunately the CL2 wire is only rated for 30V if it is carrying any current (150V with a miniscule current). I use it for 36V circuits with no worries but I would go by the book when it comes to 286V circuits.

So another option is extension cord/lamp wire. Home Depot is temporarily selling 3 packs of these for $3 in their Christmas section, normally cost $1.37 for a 6 footer at Walmart. Gives you plugs, outlets and 30ft of 300V rated, 16 gauge wire, $0.10/foot, normally $0.40/foot for lamp wire by the foot and the plugs themselves can be expensive.

 

[Kuifje76]

thanks, a little less chance to electrocute myself ...

 

[dimebagor]

hey guys n what this kind of driver ?
I can see there is emplacement for the led wire , the dim conector , but how do you power this thing ?
With an universal transformator ?

anyway outp volt max 80V , available at 1.5A or 2A and dimmable... could be fine for cxa3590 ?
cuz its 40$ , so not very expensive

 

[dimebagor]

Guys , I am SO lost ....
Definitively there is something I really didn't understood .
Thx Supra and others for explications but , with my poor English and technic vocabulary ... you know ....

Here I found someone who have post on another forum, he run single vero29 with this driver : Mean Well LPF 90-48
http://www.mouser.fr/ProductDetail/Mean-Well/LPF-90-48/?qs=b6MN4iAoYlyAdqlEXPzVfQ==

output 48V output current 1.88A !!
Than he said " At 40 volts, it should supply about 2250 mA of current."
and it runs !!
https://mycotopia.net/topic/92773-building-a-cob-style-led/

How it is possible ,first the driver is 1.88A max, and as far as I know the vero29 at 40V seems to have 4.2A output !!??!!
And for you , why he didn't buy ( except the stock reason ) the LPF-90-42 ( output 42V ; 2.15A max )
Should be better for vero29 huh??

Led is gonna be to drive me crazy really

 

[Observe & Report]

Guys , I am SO lost ....
Here I found someone who have post on another forum, he run single vero29 with this driver : Mean Well LPF 90-48

If you check the _Electrical Characteristics and Driver Selection Voltages_ table in the datasheet, you'll see that the Vf of the '29 could be over 42V when cold @ 2.1A. Forward Voltage is higher when the LED is cold, lower as it heats up. Maybe the LPF90-42 can start your '29s when cold but they might not even if everything is within specification. That makes the 48V version of the LPF90 the conservative choice.

 

[JavaCo]

Guys , I am SO lost ....
Definitively there is something I really didn't understood .
Thx Supra and others for explications but , with my poor English and technic vocabulary ... you know ....

Here I found someone who have post on another forum, he run single vero29 with this driver : Mean Well LPF 90-48
http://www.mouser.fr/ProductDetail/Mean-Well/LPF-90-48/?qs=b6MN4iAoYlyAdqlEXPzVfQ==

output 48V output current 1.88A !!
Than he said " At 40 volts, it should supply about 2250 mA of current."
and it runs !!
https://mycotopia.net/topic/92773-building-a-cob-style-led/

How it is possible ,first the driver is 1.88A max, and as far as I know the vero29 at 40V seems to have 4.2A output !!??!!
And for you , why he didn't buy ( except the stock reason ) the LPF-90-42 ( output 42V ; 2.15A max )
Should be better for vero29 huh??

Led is gonna be to drive me crazy really

He is wrong the LPF-90-48 will not put out 2250mA . It might put out 50 mA more then the rated 1880mA but thats about it. Voltage has nothing to do with the current output. These are Constant Current Drivers. So A lpf-90-48 Will put out roughly 1880 mA between 28.8 to 48 volts.

I agree with Observe on the LPF-90-42 it is cutting it really close on the upper voltage. You could have start up problems when cold. The Vero 29 data sheet has 42.5 volts as a maximum Vf @ 25 C and 43.5 Vf @ -40 C. But they Also list 38.6 Vf as the typical forward voltage for a Vero 29 @ 25c . So looking at the data sheet i would say most Vero 29's would work with the LPF-90-42 @ room temperature, But i also would not be surprised if a few didn't, especially if it is cold. It is right there on the edge.

 

[dimebagor]

If you check the _Electrical Characteristics and Driver Selection Voltages_ table in the datasheet, you'll see that the Vf of the '29 could be over 42V when cold @ 2.1A. Forward Voltage is higher when the LED is cold, lower as it heats up. Maybe the LPF90-42 can start your '29s when cold but they might not even if everything is within specification. That makes the 48V version of the LPF90 the conservative choice.

ok for the vero29 my bad , but for the driver ?
How can it provides 2.2A as the max is 1.88A ?
Even if 5% tolerance , it provides 940mA more ...

 

[Observe & Report]

ah, I didn't see the claim about the current. JavaCo is right on. The driver design has a maximum power (90W) and with slight adjustments they can produce models with higher currents and lower voltages or vice-versa as long as the power is under 90W.

 

[dimebagor]

He is wrong the LPF-90-48 will not put out 2250mA . It might put out 50 mA more then the rated 1880mA but thats about it. Voltage has nothing to do with the current output. These are Constant Current Drivers. So A lpf-90-48 Will put out roughly 1880 mA between 28.8 to 48 volts.

I agree with Observe on the LPF-90-42 it is cutting it really close on the upper voltage. You could have start up problems when cold. The Vero 29 data sheet has 42.5 volts as a maximum Vf @ 25 C and 43.5 Vf @ -40 C. But they Also list 38.6 Vf as the typical forward voltage for a Vero 29 @ 25c . So looking at the data sheet i would say most Vero 29's would work with the LPF-90-42 @ room temperature, But i also would not be surprised if a few didn't, especially if it is cold. It is right there on the edge.

Haha , ok , I'm not totally disappointed lol ...
So the 48V model is better than the 42 even the 48V got 1.88A
So after read the graph datasheet , the vero29 at 1.88A should run at 40.5V~ ???

Hope I'm correct

 

[JavaCo]

After it is warm it will typically run about 38 volts maybe even in the high 37 volts @ 1.88 amps. Vf is set by the resistance of the LED array when powered on. So it will very from chip to chip.

 

[SupraSPL]

I recently tested a Vero29 @ 2.23A. At startup (Tj 23C) it was 39.2Vf, warmed up it was 38.6. Based on that, the LPF-90-42 should be no problem. But for about the same price, the HLN-80H-42 should work and it is dimmable if that does anything for your design. I plan on testing the HLN-80H-36 to see if I can make it work with the Vero29.

 

[Kuifje76]

I wonder why buck puck's aren't used more, is there a reason ? seems you can dim all the way to 0.
do you lose to much efficienty ?

 

[JavaCo]

I wonder why buck puck's aren't used more, is there a reason ? seems you can dim all the way to 0.
do you lose to much efficiency ?

They only go up to 32 volts on the output and so they wouldn't work for the cobs we are using. The AC input models require low AC voltage 7-24 volts. So not something your average DIY'er is going to want to deal with. They do have a boost puck that goes up to 48 volts but you have to power it with a DC power supply. Once you go that route it make is more inefficient since most DC power supplies are are in the 80%'s efficiency. So you are much better off getting a Driver that has 120 volt AC input and high efficiency.

 

[SupraSPL]

Well put Java.

You can dim to almost zero with the Mean Wells that use external dimmers (B versions), although I recall someone warned not to take it below 10% for driver safety? I can verify my HLG-185H-C1050B dimmed a pair of CXA3070s down as low as 20 MA smoothly.

 

[dimebagor]

They only go up to 32 volts on the output and so they wouldn't work for the cobs we are using. The AC input models require low AC voltage 7-24 volts. So not something your average DIY'er is going to want to deal with. They do have a boost puck that goes up to 48 volts but you have to power it with a DC power supply. Once you go that route it make is more inefficient since most DC power supplies are are in the 80%'s efficiency. So you are much better off getting a Driver that has 120 volt AC input and high efficiency.

When you talk about buck puck , you mean this things like this ?
http://www.taskled.com/techhboost.shtml

Becuz the thing can outp 80V @ 1.5A it seems