DGL Fox Posted January 2, 2016 Posted January 2, 2016 We have twin 50 watt landing lights in our Sportstar which were your normal bulbed type lights, we decided to change them to LED's, very simple change, we did not have to change any wiring just take the old units out and fit the LED's in. We went a fly today and there is some sort of interference that affecting the radio, we couldn't work out where the noise was coming from until we turned the lights off once we did that the noise through our headsets was gone, never had this noise when I had the old bulbed lights in the plane. Does anyone have any idea on why we would be getting such a noise and how we can suppress it, any help would be appreciated, thanks. David
cscotthendry Posted January 2, 2016 Posted January 2, 2016 David: There may be controlling circuitry in the LED units that are generating EMI into the radio. A simple fix to try is to go to Jaycar and get some of those ferrite suppressors to put on the wires. May or may not work but it's cheap enough to try. http://www.jaycar.com.au/Passive-Components/Ferrites%2C-Inductors-%26-Suppression/Bars%2C-Beads%2C-Sleeves-%26-Cores/U15-Ferrite-Voltage-Spike-Protectors-Noise-Suppressors---Pk-2/p/LF1294 2
Blueadventures Posted January 2, 2016 Posted January 2, 2016 We have twin 50 watt landing lights in our Sportstar which were your normal bulbed type lights, we decided to change them to LED's, very simple change, we did not have to change any wiring just take the old units out and fit the LED's in.We went a fly today and there is some sort of interference that affecting the radio, we couldn't work out where the noise was coming from until we turned the lights off once we did that the noise through our headsets was gone, never had this noise when I had the old bulbed lights in the plane. Does anyone have any idea on why we would be getting such a noise and how we can suppress it, any help would be appreciated, thanks. David [ATTACH]40477[/ATTACH] [ATTACH]40478[/ATTACH] Hi David I just sent some info that may assist to your company email contact address; as it was 2MB and therefore too big to send via this forum. Cheers Mike
Kyle Communications Posted January 3, 2016 Posted January 3, 2016 Crappy switchmode power supply for the LEDS...as usual. It all goes to price...you can make good switchmodes that dont put out high freq crap...but they cost another 10 bucks in parts and no one seems to want to pay that...I would...I am sick of trying to shut up switcmode sh!t 1 1
Blueadventures Posted January 3, 2016 Posted January 3, 2016 I Have same issue, any chance of sharing fix? Hi Jetjr and Scott PM your emails and I'll send you what I sent David; its 2MB so can't post here, or if you like pm David (DGL Fox) and he could forward my emial to you. (PS I included Scotts info in my word document as it an evolving list re LED problems and fixes.) Cheers Mike
Kyle Communications Posted January 3, 2016 Posted January 3, 2016 Send it to me please mike.. [email protected] would like to see what it says
DGL Fox Posted January 3, 2016 Author Posted January 3, 2016 Yes I will chase up the correct LED's today through the supplier that supplied me the one's I fitted, I will also ask him why he didn't give me the correct ones in the first place as I did explain to him it was going into an aircraft...they needed to be EMC compliant as per the info that Mike sent me, thanks again Mike. David
jetjr Posted January 3, 2016 Posted January 3, 2016 Can the power supply board be swapped out? Problem is that very few high powered LED can fit into similar 50mm housing. Heat is another issue in enclosed housing. Plenty of low powered ones do but my experience says waste of time.
DGL Fox Posted January 4, 2016 Author Posted January 4, 2016 jetjr, From what I have found out it is the wiring/board inside the LED that creates the EM interference, not the wires or power supply, we need to find true clean LED's but that is the problem as they all say that theirs are compliant...as far as my LED's are concerned they are not...I hope to go and talk to another supplier tomorrow that seems switched on to the problem, I will keep you updated on what I find out... David
jetjr Posted January 4, 2016 Posted January 4, 2016 Ill have a look, mine are three LED, very bright, think they are just on a board by themselves, theres a small separate board on incoming power - might be overtemp temp shutdown too
Blueadventures Posted January 4, 2016 Posted January 4, 2016 jetjr,From what I have found out it is the wiring/board inside the LED that creates the EM interference, not the wires or power supply, we need to find true clean LED's but that is the problem as they all say that theirs are compliant...as far as my LED's are concerned they are not...I hope to go and talk to another supplier tomorrow that seems switched on to the problem, I will keep you updated on what I find out... David Hi David My landing / taxi light is Aero brand and strobes are Aveo brand and these given no interferrence. Cheers Mike
DGL Fox Posted January 4, 2016 Author Posted January 4, 2016 Hi Mike, Ok where did you buy your landing light, do you have a link Mike? thanks David
Blueadventures Posted January 4, 2016 Posted January 4, 2016 Hi Mike,Ok where did you buy your landing light, do you have a link Mike? thanks David Hi David From Aircraft Spruce. They have a good range. Also may be worth asking Ianwells on the forum as he has a round one on his savannah and it must not cause interferrence. Cheers Mike
Downunder Posted January 4, 2016 Posted January 4, 2016 Bit of a lucky dip whether the Auto ones cause interference...... some do, some don't. Aviation specific ones are $$$ ....
DGL Fox Posted January 4, 2016 Author Posted January 4, 2016 Yes you are right there Downunder, I think you will have a better chance buying European made lights than the ones made in China...the ones made specifically for aircraft are very expensive from what I have seen and also they don't seem to make the small 50mm MR16 type light bulbs that I am looking for ... David
jetjr Posted January 4, 2016 Posted January 4, 2016 Very few high power 50mm available, none im aware of in aviation types whatever the cost. I think theres a missing product here...........you can buy the boards, lenses and LED on ebay.
jetjr Posted January 5, 2016 Posted January 5, 2016 Whats the proper way to use ferrites in an application like this? One on each wire? Or can pos and neg go theough together? Will twisting wires the length do anything? Two passes of wire theough ferrite?
Kyle Communications Posted January 5, 2016 Posted January 5, 2016 Loop the wire as many times as you can through the ferrites. You can twist both together then wind them through or do each wire individually...you may need to try all methods and the ferrites must be right up at the source as close as possible. You are trying to stop the EM from using the length of wire to the LED as a antenna
Kyle Communications Posted January 5, 2016 Posted January 5, 2016 Also make sure the ferrites you use are for under 1 mhz most switching noise is 200 to 400 khz
DGL Fox Posted January 6, 2016 Author Posted January 6, 2016 jetjr, I don't think ferrites will stop the interference as it is coming from the LED bulb itself, not the wires...you can try I guess.. David
Kyle Communications Posted January 6, 2016 Posted January 6, 2016 I havent heard of the actual LED radiating EM it is just a chemical reaction when DC is supplied. The issue is the power supply to the actual LED. Maybe the power supply is built into the back of the actual LED then it would be difficult but it is still radiating back along the wires from the LED 1
Yenn Posted January 6, 2016 Posted January 6, 2016 Has anyone built their own LED landing lights. I have seen reports on homebuilt lights, but the LED availability seems to be in a constant state of change. Most of the homebuilts are with LEDs no longer available. From what I can work out the noise comes from the LED driversn not the actual LED.
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