Biopowered - vegetable oil and biodiesel forum
General => Chatter => Topic started by: Julian on December 18, 2012, 08:17:34 PM
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Trying to fit LED lights in the kitchen. I want two strips of multi coloured and two white. Jules expertly pointed out that the little controllers sold with the multicoloured strips are only rated for one strip and I want to run two.
No problem I thought and bought a higher rated controller and transformer. On opening the transformer it's electronic, what ever that means, and requires a load of 35w to work. It is not marked with positive or negative, just 11.6v output. I understand for a normal lamp (for which the transformer is designed) the pos and neg are unimportant, but these LED strips are positive cathode so obviously polarity is important.
When I put a multi meter on the transformer output, it measured nothing ... needs a 35w load thinks I so I stuck a lamp on it (which lit) and tried testing for polarity again. The merer still refuses to show any reading and obviously polarity.
Anyone any idea where I'm going wrong ... I'm obviously doing something stupid, but I'm not smart enough to work out what.
Can I damage these strips or the controller if I get the polarity wrong?
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Sounds like the transformer is outputting AC not DC. Try the AC reading on your MM and see what you get. You will need to put a rectifier on it to get DC.
Dick
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You could try putting a diode in series with your lamp (use a decent current rating rectifier diode - 5A or so).
If it lights with the diode in either polarity then your transformer is putting out AC
If it lights with the diode one way round but not the other then you can work out which is the positive and which is neutral.
Alternatively, could you not use two controllers but just one remote. I'm pretty sure (although not tested this theory) that the remotes all use the same codes so, presumably, proving both IR receivers were able to 'see' the remote then both controllers would react identically.
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Dick ... I tried the meter on AC and got a reading but only 0.7v!
The more I think about it, it may well be AC. The transformer is for these dichroic 12v lamps ... are they AC or DC?
Jules ... I can just about handle rudimentary electrics, but electronics has always baffled me. I think I can tell a diode from other components, but how would I know the rating? My only source of parts will be electronic gadgets I have hanging around.
I did think of a separate transformer and controller for each strip and I also though that the signals would be the same, but they aren't always very responsive and would probably not control simultaneously. Th one I bought is wireless instead of IR so the receiver can be tucked to the back out of sight.
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Trying to fit LED lights in the kitchen. I want two strips of multi coloured and two white. Jules expertly pointed out that the little controllers sold with the multicoloured strips are only rated for one strip and I want to run two.
No problem I thought and bought a higher rated controller and transformer. On opening the transformer it's electronic, what ever that means, and requires a load of 35w to work. It is not marked with positive or negative, just 11.6v output. I understand for a normal lamp (for which the transformer is designed) the pos and neg are unimportant, but these LED strips are positive cathode so obviously polarity is important.
When I put a multi meter on the transformer output, it measured nothing ... needs a 35w load thinks I so I stuck a lamp on it (which lit) and tried testing for polarity again. The merer still refuses to show any reading and obviously polarity.
Anyone any idea where I'm going wrong ... I'm obviously doing something stupid, but I'm not smart enough to work out what.
Can I damage these strips or the controller if I get the polarity wrong?
You wont damage the strips by putting the wrong polarity across them they just wont light, you will need a 12v ish dc supply for them to work.On the other hand the controller is likely to get damaged from wrong polarity.
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Trying to fit LED lights in the kitchen. I want two strips of multi coloured and two white. Jules expertly pointed out that the little controllers sold with the multicoloured strips are only rated for one strip and I want to run two.
No problem I thought and bought a higher rated controller and transformer. On opening the transformer it's electronic, what ever that means, and requires a load of 35w to work. It is not marked with positive or negative, just 11.6v output. I understand for a normal lamp (for which the transformer is designed) the pos and neg are unimportant, but these LED strips are positive cathode so obviously polarity is important.
When I put a multi meter on the transformer output, it measured nothing ... needs a 35w load thinks I so I stuck a lamp on it (which lit) and tried testing for polarity again. The merer still refuses to show any reading and obviously polarity.
Anyone any idea where I'm going wrong ... I'm obviously doing something stupid, but I'm not smart enough to work out what.
Can I damage these strips or the controller if I get the polarity wrong?
You wont damage the strips by putting the wrong polarity across them they just wont light, you will need a 12v ish dc supply for them to work.On the other hand the controller is likely to get damaged from wrong polarity.
Thanks for that, I could test it using the white strips (although they appear to be the multi coloured strips wired differently) as they don't need the controller. What if the output is AC ... will that do damage?
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Just put my glasses on and strained to read the tiny printing on the transformer ... it's inconveniently located on top of a tall larder unit and I can just make out a small squiggle after the 11.6v, so I'm guessing that means it's AC ... bugger!
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I suspect you would have no issues feeding AC, but i dont know whats in the box.
However,
If youre only after 35w, then a diode ring would be, well, 4 diodes, and then youre to DC, all be it with some ripple (which, on somthing like this, wont be an issue, im sure!)
Here you go -
(http://www.transtutors.com/userfiles/image/GLOSSARY/Diode%20rectifier(1).jpg)
Personally, id just plug it in a see if it worked. I think the chances of the magic smoke leaking out are slim.
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It was 35w minimum load to get the transformer to operate, it's rated at 25 amps on the secondary.
I did a bit of Googling on rectifiers for LEDs and several forums said that you needed capacitors along with the rectifier, I'm guessing from a perspective of little electronic knowledge , to smooth the output.
Anyhow realising that it's an AC output, it's not what I need, so I've ordered a 30 amp output dedicated LED driver which is cheaper. The 25 amp unit was from Screwfix so hopefully they'll take it back.
Thanks to everyone for the assistance ... fingers crossed everything works this time!
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Can't believe you lot are letting him get away with this thread, I for am going to retaliate by excessive use of the following:
:) ;) :D ;D >:( :( :o 8) ??? ::) :P :-[ :-X :-\ :'( :'( :'( :'( :'( :-* :-\ :-X :-[ :P
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i got a question on therse RGB lights if i cut the strip into 3 do i need 3 controllers?
i got 1 box/remote and 1 strip light
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No, if you can join the three strips with wire, they will still run off the one controller.
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No, if you can join the three strips with wire, they will still run off the one controller.
kool
but if i only want 2 jioned and the third with just an off on switch via 12 volt is the odd strip ok for this?
i guess i have to jion 3 wires togethrer and thats the live, and 4th the earth, is this right?
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Re the third strip on 12v, I'll have to check. I've got multi colour bought as white with only two wires attached (they obviously don't need the controller) ... I'll check how they are connected an report back.
In joining the other strips, there are four wires, 12v positive and the three colours (RGB), you'll need one wire for all 4. I bought some connectors that work quite well, but as Jules stated, you can just solder to the contacts once the silicone is cleaned off.
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Re the third strip on 12v, I'll have to check. I've got multi colour bought as white with only two wires attached (they obviously don't need the controller) ... I'll check how they are connected an report back.
In joining the other strips, there are four wires, 12v positive and the three colours (RGB), you'll need one wire for all 4. I bought some connectors that work quite well, but as Jules stated, you can just solder to the contacts once the silicone is cleaned off.
cheers
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OK, pulled a connection appart on a "white" strip ... referring to the four copper connections where you cut the strips, positive is connected to (surprisingly) the positive wire and the other three are joined with a bridge of solder and connected to the negative wire.
Logically to make the primary colours you'd connect positive to positive and then the negative to either R, G or B as required.
On one of my strips RGB isn't marked, but it appears that the standard colour sequence is + G R B
If it's any help the new uprated RF controller is a vast improvement on the IR controller usually supplied with the strips.
Hope that helps.
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thx got a link or pic of that new rf thing?
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I got it here ... http://www.ebay.co.uk/itm/170778529916?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648
It's only really necessary if you want to run more than one strip and have them work in sink (in which case you'll need an uprated transformer too), or if you want the controller hidden away.
Waiting for this to arrive (you can choose the rating to suit the number of strips ... I chose the next size up just to be on the safe side) ... http://www.ebay.co.uk/itm/230845090623?var=530075032447&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648
It all starts to add up if you want something other than one standard strip!
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This gets worse!
My nice big 30 amp power supply arrived today and the bloody thing is cooled with a fan ... a noisy fan. No mention of fans in the advert that I remember. So I can have nice pretty light only when accompanied by an annoying drone.
And the double sided tape on the strips obviously doesn't like Melamine because they are detaching when mounted on a horizontal surface.
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Did you wipe down the melamine with IPA first? That is what I did in the caravan and they have stuck to the underside of cupboards and the like ncely. The caravan vibrates and flexes whilst being towed (certainly compared to a house anyway) and they are still stuck.
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Yes scrupulously.
Played this game recently for a large retailer, trying to get doublesided tape to stick to powder coat. Ended up having shelving tested at 3M Bracknell who are recommending the 4th type of tape for the job.
I re-taped the strips with one of their previous recommendations for low energy surfaces and it worked fine.
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If it is over rated can you disconnect the fan or put a resistor in series to slow it down and cut the drone?
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It was well over rated ... I felt it best with cheap items made in the East!
Seller has agreed to swap it for a 20 amp version without a fan which is still slightly over rated for my application, so hopefully all will be good.
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It was well over rated ... I felt it best with cheap items made in the East!
Seller has agreed to swap it for a 20 amp version without a fan which is still slightly over rated for my application, so hopefully all will be good.
That's good to hear.