eelm Posted November 24, 2013 Share Posted November 24, 2013 Hi to everyone and sorry if this has been already asked over and over but I am a bit confused and would like to be sure of one thing.I am about to order a CMB16D-QC to control my DC lights and I have a question regarding the psu I will have to use.Considering that there will be between 12 to 14 rope lights that are for some 24vdc and for most of the others 36vdc, what type of psu would then be needed ?I assume a 12v 300w would not be sufficient right ? I would more have to go for one like this http://www.ebay.com/itm/Mean-Well-MW-27-36-48V-350W-450W-600W-1000W-1500W-AC-DC-Switching-Power-Supply-/111223740822?pt=LH_DefaultDomain_0&var=&hash=item19e5739996 like (36v 350w) Thanks Seb Link to comment Share on other sites More sharing options...
eelm Posted November 24, 2013 Author Share Posted November 24, 2013 Or would it be more advised to go for a 48v 350w ? Seb Link to comment Share on other sites More sharing options...
k6ccc Posted November 24, 2013 Share Posted November 24, 2013 Since you have both 36V light rope and 24V light rope, you would need 2 power supplies. The controller has 2 power banks and they can be different voltages. You would connect a 24V power supply to one bank and the 36V power supply to the other. For this example, I am viewing the board with the input power connections at the bottom of the board and output channels 1 - 8 on the right side and channels 9 - 16 on the left side. Let's say for example that you connect your 24V power supply to the right side power inputs, then you would use channels 1 - 8 for your 24V light rope. Then connect your 36V power supply to the left side power inputs and connect your 36V light rope to channels 9 - 16. The ebay power supplies in your link should do the job. Add up your load before selecting the wattage rating for each power. Remember, you will need two of them to get the 2 different voltages (one 36V and the other the 27V - which should be adjustable down to 24, or at least close enough). If you have additional questions about this, feel free to ask. Most of my LOR controllers in use are DC, so I am quite familiar with them. Link to comment Share on other sites More sharing options...
eelm Posted November 24, 2013 Author Share Posted November 24, 2013 Thanks Jim. It s clear for me now. Seb Link to comment Share on other sites More sharing options...
scubado Posted November 24, 2013 Share Posted November 24, 2013 You can also have more than 2 different voltages on the same controller. You can have 5v, 12v, 24v and 36v and more if you wish. You run the '+' off the PS directly to the element. The controller only needs to control ground. Sometimes the PS doesn't need to have the ground hooked up to the controller. Link to comment Share on other sites More sharing options...
scubado Posted November 24, 2013 Share Posted November 24, 2013 You can't do the above trick on a three channel DMX controller, not sure if the bigger dmx controllers can do it or not. Link to comment Share on other sites More sharing options...
k6ccc Posted November 24, 2013 Share Posted November 24, 2013 You can also have more than 2 different voltages on the same controller. You can have 5v, 12v, 24v and 36v and more if you wish. You run the '+' off the PS directly to the element. The controller only needs to control ground. Sometimes the PS doesn't need to have the ground hooked up to the controller. That's an interesting concept. Certainly not a supported operating mode, but I don't see any reason why it would not work. You are completely correct that other than powering the controller board itself, there is no need to supply the + side of the power supply to the controller. I think you would have to have all the various power supply - voltages connected to the - input (or inputs) on the controller. I can post a drawing if desired... BTW Seb, since you said that most of your light rope is 36 volts, a variation of this might help you if you need more than eight 36V outputs. Link to comment Share on other sites More sharing options...
scubado Posted November 24, 2013 Share Posted November 24, 2013 It does work, I do it all the time. In my garage, I have an old computer PS, I only use one hot lead off of it, no ground. Computer power supplies use neutral ground, thereby not needing to homerun a ground wire. On the single voltage power supplies we all are using, the output ground seems to be isolated from neutral ground and needs to connect to the controller. It is also safe to connect the ground outputs together. Link to comment Share on other sites More sharing options...
eelm Posted November 25, 2013 Author Share Posted November 25, 2013 ok you managed both to lose me on that one Not sure I really get it but I have ordered one 36 and one 24 psu. Still have to look for a ventilated enclosure as this might become warm I suppose as this will be outside as I don t have a garage.I might soon order an extra controller anyway as I found some more lights lying around from previous years so even if I use only one psu today, I will use the other one one day or another as this all lighting thing is a bit like pringles (once you pop you can't stop) Scubado, you said that you could have more than 2 different voltages on the same controller with the + connected directly to the element and the - on the bank but you would have to change the power output on the psu for this right ?What I don't understand and correct me if I am wrong is that you don't specify on the controller itself the power per channel. So how do you manage to do this ? The +/- option on the psu is for the whole output no ?And if you don t put the + on the board how does it get powered ? Do you need an extra power connected on the auxiliary one on the side plug ? As per what I understand in the manual the board is powered with bank 1-8. I will have a look as we have a pile of old computers. Maybe this also is something to look into. Sorry to have so many question and to be such a pain but this is fairly new to me. This year it is already too late to come up with something but next year will be fun. Seb Link to comment Share on other sites More sharing options...
scubado Posted November 25, 2013 Share Posted November 25, 2013 The controller has to have 12v to run the controller and used to run lights that require the 12v. When you have an RGB item, the + leg is common to all three colors in that item. The item receives it's + voltage constantly, always on, the controller channels supply ground to turn ON the item. The + voltage for the item can come from any source, whether it's from the controller or directly from the PS. I have a LOR ticket opened on this topic because looking at the specs of the controller, this controller only allows up to 30v connected to the board. My 16 channel controllers allow 60v connected to controller. It should still work, but want to hear what LOR says about it. I wonder if LOR can revise the controller since new high powered leds are using 36v to keep current levels down. Link to comment Share on other sites More sharing options...
scubado Posted November 26, 2013 Share Posted November 26, 2013 According to LOR at this time, the 24 channel cannot use the 36v leds. My ticket is still active with Dan, he wanted some more info from me. I pointed Dan to this thread as one of my reasons for the ticket. Link to comment Share on other sites More sharing options...
eelm Posted November 26, 2013 Author Share Posted November 26, 2013 Indeed, because of the 30v limit I ordered the cmb16d-qc otherwise would have gone for the 24.Been looking around in shops here and as you say most of the led strings are 36v. Link to comment Share on other sites More sharing options...
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