Reef Discussion
If your running the ldd boards then im not sure how you could safely switch the individual strings. The pwm take the signal from your controller to the led via the driver. If you had a controller I'm not sure why you would still need a switch. If you we're not using a controller someone else would have to advise if you can switch via the pwm as I don't know the answer to that but doesn't sound likely given it would be no different to having no controller and therefore the ldd would just run at 100% would be my thought.
Again I'm not sure so don't take my word for it though.
Again I'm not sure so don't take my word for it though.
Any thoughts on this @MagicJ ?
Apologies for not responding earlier - I have been trying to get the controller sketch finished off ;)
What you are trying to achieve is best down in your Arduino sketch.
As for using a physical switch, I would need to do some testing - switching the PWM control wire MAY work but this is not the same as outputting a zero duty cycle PWM signal so I am not sure. Putting the switch on the LED string would obviously work and shouldn't do the driver any damage although the minimum output voltage as per the spec sheet is around 2v so I would not guarantee that some smoke would not escape somewhere.
I will see if I can do some testing tomorrow night.
What you are trying to achieve is best down in your Arduino sketch.
As for using a physical switch, I would need to do some testing - switching the PWM control wire MAY work but this is not the same as outputting a zero duty cycle PWM signal so I am not sure. Putting the switch on the LED string would obviously work and shouldn't do the driver any damage although the minimum output voltage as per the spec sheet is around 2v so I would not guarantee that some smoke would not escape somewhere.
I will see if I can do some testing tomorrow night.
And how is it going ehre @MagicJ ;)
How's everyone progressing with the new drivers? Anyone got them up and fully running?
I decided to add some exotics to my setup seeing as it was easy now to add further LED strings with the new driver and thanks to @MagicJ's neat board.
My new LEDs have arrived so I'll be doing some Easter soldering/wiring.
I mentioned before about wanting to be able to 'switch' off/on each string so that I can see them individually for their effect.
I've worked out that I'll have a series of buttons that will work from the arduino sketch that will do the individual on/off functions. Hopefully that will work OK.
Has anyone tried to turn the individual strings on/off?
I'm hoping the previous sketch for dimming will be workable for the new setup also. Has anyone written a sketch that works for the new drivers?
I decided to add some exotics to my setup seeing as it was easy now to add further LED strings with the new driver and thanks to @MagicJ's neat board.
My new LEDs have arrived so I'll be doing some Easter soldering/wiring.
I mentioned before about wanting to be able to 'switch' off/on each string so that I can see them individually for their effect.
I've worked out that I'll have a series of buttons that will work from the arduino sketch that will do the individual on/off functions. Hopefully that will work OK.
Has anyone tried to turn the individual strings on/off?
I'm hoping the previous sketch for dimming will be workable for the new setup also. Has anyone written a sketch that works for the new drivers?
Hey guys, just joined thereefuge, long time lurker, never needed a post before though. Very interested in these drivers, was looking at building a cat4101 based driver to run my DIY LED setup but may just run these instead. Can I please ask of those of you organising the boards and chips, what are the costs atm, I am looking at ~100 leds, but will need to modify my layout to make better use of these drivers. Then I will know exactly how many I am looking at.
Cheers and thanks for having me.
Glenn
Cheers and thanks for having me.
Glenn
@Terminatermule :welcome
Hi Glenn
For 100 leds you will need around 9 drivers (based on a 48v power supply and around 12 leds per driver) - the boards we have hold 5 drivers so lets up it to 10 drivers and 2 boards. Please note that there is no requirement to use these boards - they just make it easier and cleaner. The boards + IC sockets + screw terminals are around $9 each.
The drivers are around $5 each - so the total cost is around $70 for 10 drivers and 2 boards. Given the cost of these drivers it is hardly worth the time and effort of making the cat4101 drivers any more.
You will also need a suitable power supply, but you would need that with the cat drivers anyway.
Cheers
Hi Glenn
For 100 leds you will need around 9 drivers (based on a 48v power supply and around 12 leds per driver) - the boards we have hold 5 drivers so lets up it to 10 drivers and 2 boards. Please note that there is no requirement to use these boards - they just make it easier and cleaner. The boards + IC sockets + screw terminals are around $9 each.
The drivers are around $5 each - so the total cost is around $70 for 10 drivers and 2 boards. Given the cost of these drivers it is hardly worth the time and effort of making the cat4101 drivers any more.
You will also need a suitable power supply, but you would need that with the cat drivers anyway.
Cheers
Thanks magicJ,
A quick question about these, I have 8 channels (colours) that I wish to run all separately, and dim separately but some of the strings will have different input requirements, with the LDD (I know I could just read the Datasheet but thought you guys may have practical experience with this in the real world) how much difference can it tolerate, and does it get really hot when there is such a difference? I know with the cat4101s it can be a serious issue, I had designed my drivers with a reg in front of every cat with a trim pot for this very reason. That way I could run the highest voltage needed for the highest/longest string on the LED array and a run a volt or so less for a few of the other strings. Is this not needed on these?
Edit:
Ok so I just read the data sheets, and aside from a drop in efficiency by driving fewer LEDs at a higher input voltage, it can cope with it just fine, unlike the CAT4101's. I like this chip more and more, so just to be sure, from those of you doing this, I have most of my strings now laid out to run 48v input, but there will be a couple that are 24 volt strings, however this seems to be perfectly fine, just not as efficient. Is that correct? I guess this chip being buck type oesn't need to sink the remainder, it just doesn't generate it?
Also MagicJ, how many of the boards/sockets/pins do you have atm? I think I would like to buy three lots of those if you have them spare. Other wise I will put in an order with seeed.
Also ( I may have asked this prior) do you have an eagle file for this board? Would like to tinker with it a little.
Cheers Glenn
A quick question about these, I have 8 channels (colours) that I wish to run all separately, and dim separately but some of the strings will have different input requirements, with the LDD (I know I could just read the Datasheet but thought you guys may have practical experience with this in the real world) how much difference can it tolerate, and does it get really hot when there is such a difference? I know with the cat4101s it can be a serious issue, I had designed my drivers with a reg in front of every cat with a trim pot for this very reason. That way I could run the highest voltage needed for the highest/longest string on the LED array and a run a volt or so less for a few of the other strings. Is this not needed on these?
Edit:
Ok so I just read the data sheets, and aside from a drop in efficiency by driving fewer LEDs at a higher input voltage, it can cope with it just fine, unlike the CAT4101's. I like this chip more and more, so just to be sure, from those of you doing this, I have most of my strings now laid out to run 48v input, but there will be a couple that are 24 volt strings, however this seems to be perfectly fine, just not as efficient. Is that correct? I guess this chip being buck type oesn't need to sink the remainder, it just doesn't generate it?
Also MagicJ, how many of the boards/sockets/pins do you have atm? I think I would like to buy three lots of those if you have them spare. Other wise I will put in an order with seeed.
Also ( I may have asked this prior) do you have an eagle file for this board? Would like to tinker with it a little.
Cheers Glenn
Hi @Terminatermule, my highest demand string is only about 45 volts and fair to say most of my strings would be well under that even. Early days for my set up but I haven't experienced any issues with my 48 volt supply set up yet.
@Terminatermule
I just read your post on Reefcentral :D
O2Surplus designed these boards and made the Eagle files freely available for anyone to use - I thought that rather than a number of members order the boards seperately that we could do a Group Buy sort of thing and order a number of them.
I wish I could design PCB's like O2 :p
I just read your post on Reefcentral :D
O2Surplus designed these boards and made the Eagle files freely available for anyone to use - I thought that rather than a number of members order the boards seperately that we could do a Group Buy sort of thing and order a number of them.
I wish I could design PCB's like O2 :p
As you noted in your edit, these LDD's are pretty handy things - they don't need to sink the excess voltage. I had some concerns over generated heat and ran a test with one led running through a 500mA LDD and a 48v power supply - this is a graph of the heat of the LDD (as measured by a DS18B20 fixed to the LDD)
So, it got about 7 degrees above ambient - you have to be happy with that :)
Refer to this post for details : http://www.thereefuge.com.au/thread...nt-current-led-drivers.5722/page-4#post-82349
Some of the members on Reefcentral have been doing some other tests - it appears that you can actually supply a current less than that required by the LDD's and the correct current will still be supplied to the led's provided that there is some overhead with the power supply. To put this another way, providing the rated wattage of the power supply exceeds the total wattage of the led's then everything should work - try this at your own risk.
I can manage 3 boards + extra's - shoot me a PM and we will get it sorted. And, yes, I do have the eagle files - include your email in the PM.
Cheers
so @MagicJ i will need a power supply with a 48 volt supply and going by your excel spread sheet 1 by 120w and 1 by can not remember?
so 48v 120w correct?
so 48v 120w correct?
Yeah I had started to gather that, it can modulate excess voltage into current flow internally, quiet efficiently too by the look of it. Very cool little device.
Thanks for that Gordon, good to hear someone doing it in real life, sometimes data sheets can skew information or put it on unrealistic terms. I have seen this many times, I used to work as a telco tech, its common for something to not go as smooth in real life as a data sheet may suggest it would.
I have worked with DC electronics a lot over the years, just not much with LEDs and their finer points. This has been an interesting project, quite enjoying it. I am steadily getting used to eagle, I have been able to build a nice (in theory) Cat4101 driver with individual trimmed voltage regs for every unit, this was to overcome the difference in string voltages. These don't need any such thing, so that is awesome.
Thanks for the info and reply. I will shoot you a PM shortly. So glad I found this thread ( and the reef central one for that matter)
Cheers Glenn
Ps - Yeah MagicJ I was like, damn gotta be that same dude, lol. It was the pic that made me think that, lol.
Thanks for that Gordon, good to hear someone doing it in real life, sometimes data sheets can skew information or put it on unrealistic terms. I have seen this many times, I used to work as a telco tech, its common for something to not go as smooth in real life as a data sheet may suggest it would.
I have worked with DC electronics a lot over the years, just not much with LEDs and their finer points. This has been an interesting project, quite enjoying it. I am steadily getting used to eagle, I have been able to build a nice (in theory) Cat4101 driver with individual trimmed voltage regs for every unit, this was to overcome the difference in string voltages. These don't need any such thing, so that is awesome.
Thanks for the info and reply. I will shoot you a PM shortly. So glad I found this thread ( and the reef central one for that matter)
Cheers Glenn
Ps - Yeah MagicJ I was like, damn gotta be that same dude, lol. It was the pic that made me think that, lol.
I can't remember if we put this up or not so here goes again if we did lol.
LDD-700H - these will be shipping from Mean well next month so I have a mid May delivery
LDD-1000H - these are not shipping until Mid May giving a Mid June delivery. Mean Well have run out of stock.
I also inquired about 500mA LDD's today, only have 3 in stock at the moment so we have put 50 of these on back order also.
So at the last count after what went out today, we have the following left........
3x 1000mA
11x 700mA
15x 350mA
Ken & Jen:)
LDD-700H - these will be shipping from Mean well next month so I have a mid May delivery
LDD-1000H - these are not shipping until Mid May giving a Mid June delivery. Mean Well have run out of stock.
I also inquired about 500mA LDD's today, only have 3 in stock at the moment so we have put 50 of these on back order also.
So at the last count after what went out today, we have the following left........
3x 1000mA
11x 700mA
15x 350mA
Ken & Jen:)
Hi guys. I just thought I'd share a solution to an issue that I was having as we'll as @macca_75 mentioned to me as well. While these boards are outstanding and make life very neat and simple, the screw shields can be difficult to get your wiring into.
Two solutions:
1. Unlike me you could use more appropriate sized wiring
2. I soldered pins out of my arduino build to the wires. You can get enough of these for about 1 buck from jaycar. Works like a dream and I easily had two wires coming out of the one hole! Big improvement from not being able to get one in easily prior to doing this.
Just thought I'd share :)
Two solutions:
1. Unlike me you could use more appropriate sized wiring
2. I soldered pins out of my arduino build to the wires. You can get enough of these for about 1 buck from jaycar. Works like a dream and I easily had two wires coming out of the one hole! Big improvement from not being able to get one in easily prior to doing this.
Just thought I'd share :)
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