bhazard451
New member
I'm about a weekend away from finally finishing my 120 led fixture made with these. The boards and LDDs made it so much nicer.
Meanwell LDD driver: for those who want to dim to 0 using Arduino
- Thread starter pwreef
- Start date
Quick question - I know that the arduino and drivers need to share a common ground for the PWM to work - but if I'm using a seperate AC power supply to power the arduino and fans, will the fact that they are sharing the AC Neutral suffice? I'm pretty confident I'm right in thinking it would be stupid to connect the two V- outs (48v & 12v) - so them sharing the same AC neg is the only thing I can think of! There is obviously a chance I'm being a moron and missing something obvious! That's why I need your help 
Damn - how would I get round that then? Would the arduino be able to handle the ground from it's own power supply connection, and also a ground taken from the 48v supply to one of its ground pins?
Thought I'd been clever using a seperate supply! Apparently not. Coupled with my hazy recollection of high school electronics it's fair to say I'm completely in the dark with this one
Thought I'd been clever using a seperate supply! Apparently not. Coupled with my hazy recollection of high school electronics it's fair to say I'm completely in the dark with this one
Kawi9_cf
Member
Hey guys I got the pull down resistors in today and they work well. It pulls them all the way to zero or completely off. I was under the impression that they would be on just dim.
Anyway here is what the modified board looks like if anyone us interested.
<a href="http://s1358.photobucket.com/albums/q775/kawi9_cf/?action=view¤t=0D02FEB9-CF52-4413-B2EB-44642AA28AF7-8482-000003E3AE2F1448_zps21d2e02f.jpg" target="_blank"><img src="http://i1358.photobucket.com/albums/q775/kawi9_cf/0D02FEB9-CF52-4413-B2EB-44642AA28AF7-8482-000003E3AE2F1448_zps21d2e02f.jpg" border="0" alt="Photobucket Pictures, Images and Photos" /></a>
Anyway here is what the modified board looks like if anyone us interested.
<a href="http://s1358.photobucket.com/albums/q775/kawi9_cf/?action=view¤t=0D02FEB9-CF52-4413-B2EB-44642AA28AF7-8482-000003E3AE2F1448_zps21d2e02f.jpg" target="_blank"><img src="http://i1358.photobucket.com/albums/q775/kawi9_cf/0D02FEB9-CF52-4413-B2EB-44642AA28AF7-8482-000003E3AE2F1448_zps21d2e02f.jpg" border="0" alt="Photobucket Pictures, Images and Photos" /></a>
Nice, Kawi9_cf. So I assume you're still able to increase it up to 100 with them on, right? It works just as proposed? I don't see why it wouldn't.
Did you end up needing to re-do any? I ended up missing the pad on two of them when I slipped and gave a bit too much heat. I was trying to get them down and had to use some copper braid remover and start over.
Did you end up needing to re-do any? I ended up missing the pad on two of them when I slipped and gave a bit too much heat. I was trying to get them down and had to use some copper braid remover and start over.
Kawi9_cf
Member
It works exactly as proposed I have full functionality of the lights when the arduino has power but with a loss of power the lights dim down.
Eud I was able to get all of mine on the first try. I lined them up and then scratched the spots off with a tiny flat blade screwdriver I use for iPhone repairs. Then I pre-tinned the scratched off spot and leaned the resistor up against the the solder and held it into place with my screwdriver while I reheated the solder. When the solder has hot again the resistor fell right into place. I don't know if that was proper way but it worked out for me
-Nick
Eud I was able to get all of mine on the first try. I lined them up and then scratched the spots off with a tiny flat blade screwdriver I use for iPhone repairs. Then I pre-tinned the scratched off spot and leaned the resistor up against the the solder and held it into place with my screwdriver while I reheated the solder. When the solder has hot again the resistor fell right into place. I don't know if that was proper way but it worked out for me
-Nick
sfsuphysics
Active member
That's super awesome, I'm going to have to look at my boards when they come to see how to rig it up to work like this. Not that I'll fry my LEDs or anything, but I think I'll notice no light in the tank rather than 100% light if the controller fails.
It works exactly as proposed I have full functionality of the lights when the arduino has power but with a loss of power the lights dim down.
Eud I was able to get all of mine on the first try. I lined them up and then scratched the spots off with a tiny flat blade screwdriver I use for iPhone repairs. Then I pre-tinned the scratched off spot and leaned the resistor up against the the solder and held it into place with my screwdriver while I reheated the solder. When the solder has hot again the resistor fell right into place. I don't know if that was proper way but it worked out for me
-Nick
Great. On mine I put them on the pads, put a drop of rosin flux on it, grabbed it with some tweezers, got a tiny bit of solder on the iron and touched it to the joint where the resistor met the pad and tried to wick it under the part and lap it up over the end.
Your way sounds easier.
Kawi9_cf
Member
I think the corals would survive better a day without light better than a day with the lights at 100% as well.
Just a quick note to anyone planning on using 25 pin D-SUB connectors to link their lighting rig to a control box - don't.
The connectors I used were from work rated at 4a - but when plugged in strings didn't light up, some flickered a bit but that was it. I soldered those suckers up real good too.
Lopped off the connector and wired straight to the 5up boards and now I'm partially blind.
I've already ordered some male and femal RCA connectors - but I was also looking at a 24 pin molex connector designed for atx power supplies. The cables are 18awg so will match with what I'm using now. Has anyone tried either before I waste another few hours of soldering? The molex would be a neater solution, but all I want now is a reliable connection - so one RCA per string will have to do if it's the most reliable/proven method.
The connectors I used were from work rated at 4a - but when plugged in strings didn't light up, some flickered a bit but that was it. I soldered those suckers up real good too.
Lopped off the connector and wired straight to the 5up boards and now I'm partially blind.
I've already ordered some male and femal RCA connectors - but I was also looking at a 24 pin molex connector designed for atx power supplies. The cables are 18awg so will match with what I'm using now. Has anyone tried either before I waste another few hours of soldering? The molex would be a neater solution, but all I want now is a reliable connection - so one RCA per string will have to do if it's the most reliable/proven method.
