Browse Forums Lighting + Lighting Design 1 Mar 29, 2010 10:53 am Hi, I wondered if anyone else has come across this phenomenon in the past??? I bought four 5w 240v downlight globes (from eBay) for the kitchen 4-spot light fitting, and while they are slightly less output than the 50w globes they replaced (not a bad thing, as 200W in the kitchen was just too much!), they are alot cooler, and I am very happy with them. I then bought some 4w 12v downlight globes from the same eBay seller to replace all the downlights in the lounge room. I changed just one of them, and found channel 7, 72 and 7-HD no longer worked on the LCD TV (very pixelated/blocky image, and no sound). Interestingly, the TV signal strength indicator shows it's just as good as other channels. The analogue TV in the bedroom shows two fuzzy horizontal bands across the screen, but otherwise is watchable (but no digital channels anyway). Replacing the rest of the globes meant only channel 9 stations worked on the digital TV. At first I thought it was the dimmer, so I disconnected it. It might be worth mentioning that the LED globe dimmed proportionally with the halogen globes when I used the dimmer, but when all globes were replaced, the LED globes no longer dimmed, but flickered at a very fast rate unless the dimmer was at maximum (ie: not dimming). I thought possibly the TV and/or TV-antenna amplifer were on the same supply phase as the light circuit, so I changed the light circuit to "A" phase (which has no power circuits), and that didn't help either. The TV-antenna amplifier is under the house, as is the antenna wire, and it's nowhere near the light circuit wiring, so that rules out that possibility... As I was disconnecting the globes, I found that one of the globes nearest to the TV seems to allow channel 7 to work properly when I drop it down from the ceiling (hanging by it's cord), and thought the aluminium "heat covers" over the globes might be reflecting any signal generated by the LED globe's "elecronics" back into the room, but this theory didn't work with any of the other 6 fittings. The globe on the other side of the room directly opposite the TV seems to have the same affect when facing it east (90-degrees perpendicularly away from the TV, and regardless of which way it is rotated (thinking the interference generated by the electronics in the globe might be directional)). This test was done with all globes removed, and only using one globe testing from each fitting to the next. The transformers are electronic type (a couple of different brands as some failed over the last few years). My next option is to connect all the globes to just one transformer, as it might be possible the 4w globe may be such a small load that it is causing the transformer to create feedback or more interference than it normally might, but the previous experiment may mean this is not the case. My last option is to replace the transformers with old iron-core transformers, before replacing all globes with 240v versions (and cross my fingers that it's not the globes themselves causing the interference!) Any ideas??? I have contacted the eBay seller to let him know of my findings. Re: Help! 12v LED downlight globes = TV interference 2Mar 29, 2010 11:10 am I'll be interested to see what gets said about this because my mum and dads house has the exact same problem! Re: Help! 12v LED downlight globes = TV interference 3Mar 29, 2010 11:31 am There are certain certifications that electronic devices need to get to ensure they don't radiate electrical noise. Sounds like this certification has not been obtained and therefore these bulbs woudl not be allowed to be sold in Australia. Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Help! 12v LED downlight globes = TV interference 4Mar 29, 2010 11:39 am Casa2 There are certain certifications that electronic devices need to get to ensure they don't radiate electrical noise. Sounds like this certification has not been obtained and therefore these bulbs woudl not be allowed to be sold in Australia. I am aware of some of these requirements. The packaging has "RoHS" and "CE" logos/labels on them, but I have also read (on the net) that some certifications are self-administered. Do you know where I'd be able to find specific requirements? Eg: Fair Trading website? Re: Help! 12v LED downlight globes = TV interference 5Mar 29, 2010 12:56 pm I've changed all the globes to run from one transformer, and the problem remains. I tried one of the older "soft-start" electronic transformers and none of the globes came on (so I changed it back to one of the other transformers). Next option is to try and old iron-core transformer - hopefully I have one ****** around the garage somewhere... It's also worth noting that the USB digital TV-tuner card in the PC also has the same reception problem, and it's in another room altogether (further away than the kitchen!). There must be quite significant interference put out by these globes! I wonder if next door's reception is affected?!?!?! I also tried swapping two of the LED globes with the halogens in the dining room (L-shaped lounge/dining) and they also affect the TV reception. I am thinking it's more to do with the 12v LED globes themselves rather than the transformers. The 240v LED globes in the kitchen (next to the dining room) don't seem to have any affect on the TV reception, and the kitchen is closer to the Tv-antenna amplifier than the lounge room. I made up a tester consisting of a transformer with a 3-pin plug on the end (for input power) and four 12v globe-leads and plugged the tester into various power points throughout the house. I get the interference on the TV reception at almost all locations throughout the house with just two 12v globes connected to the tester, however only some combinations of directions of globe and transformer seem to affect it. I plugged the tester into the power point in the bedroom behind the big TV and it didn't affect reception at all, however when I plugged the tester into the power point above the TV-amplifier (at the back of the house, nowhere near the big TV) it affects reception just as bad as having all the LED lights on in the lounge room. Perhaps the sum of the LED globes in the lounge room increases the interference signal strength enough to reach the TV-antenna amplifier... Probably no point in trying an iron-core transformer. I think I'll just get some 240v globe-leads and try the four 240v globes from the kitchen in a tester, then the lounge room if the tester works OK... Re: Help! 12v LED downlight globes = TV interference 6Mar 29, 2010 5:21 pm Equipment that needs to be EMC compliant must carry the c-tick (see http://www.acma.gov.au/WEB/STANDARD/pc=PC_2796). Not sure if light bulbs fall under the requirments. Will check. Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Help! 12v LED downlight globes = TV interference 7Mar 29, 2010 5:23 pm Take a read of http://www.acma.gov.au/webwr/_assets/ma ... 20fs35.pdf Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Help! 12v LED downlight globes = TV interference 8Mar 29, 2010 6:20 pm Thanks for that. I have brought it to the attention of the seller. I wonder what will happen once he becomes aware *he* is responsible for ensuring compliance? I know there was a contact at the end of the document, but would Fair Trading be responsible for enforcing compliance? Re: Help! 12v LED downlight globes = TV interference 9Mar 29, 2010 8:38 pm Hi all I have the exact same problem. I just invested in $600 of LEDs bulbs (MR16 9W 3x3w) LED and drivers and apart from the flickering, its the reception interference that is most annoying. I have tried all sorts of combinations with the drivers but to no avail. I bought my bulbs from a Queensland distributer. Re: Help! 12v LED downlight globes = TV interference 10Mar 29, 2010 9:12 pm Masada, do you know what certifications the globes have? I've googled the certifications my globes have... CE = http://en.wikipedia.org/wiki/CE_mark RoHS (Restrictions of Hazardous Substances) = http://www.rohsguide.com/rohs-faq.htm I am not surprised about the possible confusion between "CE" and "China Export" using almost the same logo, as mentioned in the wiki page... The CE logo on the packaging with my globes is in fact the correct one, and not the "China Export" copy Re: Help! 12v LED downlight globes = TV interference 12Mar 29, 2010 9:39 pm borg what could be making things worse is that you have a near by amplifier. This will make noise a even greater issue. I assume you're referring to the TV-antenna amplifier and not the stereo amplifier... The only way I could move the Tv-antenna amplifier further away would be to enclose it in a weatherproof case and mount it on the wall at the back of the house. Not exactly practical, but doable. I wonder if it's the antenna cabling that is picking up the interference and not the amplifier itself. The cabling is clipped to the beams under the timber floor. It is fairly new cabling (I put it in a few years ago). I wonder if it's worth trying to shield the amplifier by placing a sheet of metal between it and the timber beam it's mounted on (to possibly reflect any interference back up, away from the amplifier)? Doing the same for the anetanna cabling would take a long time. I could also re-route the cabling around the house so it's away from the lounge-room floor. Re: Help! 12v LED downlight globes = TV interference 13Mar 30, 2010 8:22 am The coax cable should have some level of protection. It may also be the connectors. Are there any corroded connectors?? Are they installed correctly. Are there any or where there any kinks in the cable. Can you adjust the gain of the amplifier? if so reduce rather than increase it. If not then add a splitter on input of the amplifer to reduce the power by 3dB approx half. Trouble is with amplifers is that they amplifiy good signal as well as bad. Re: Help! 12v LED downlight globes = TV interference 14Mar 30, 2010 4:10 pm The connectors should be fine as I only installed them about 6-9 months ago, but will check. Cabling is all OK too. I can adjust the amplifier gain so will give it a try. It might be up too high to compensate for the number of outlets I have. Re: Help! 12v LED downlight globes = TV interference 17Mar 31, 2010 6:28 pm Progress this afternoon after finding a torroidal transformer in the garage (salvaged from an old Crompton surface-mount halogen fitting) and picking up four GU10 globe-holders from the wholesaler... The torroidal transformer made no difference; the interference is still present with only two 12v LED globes connected to it. The four GU10 globes however, was a success. I still have to try winding down the gain on the TV amplifier which I hope to try tomorrow, but I don't think it'll make any difference, as the interfering signal is probably already stronger than the TV-station broadcast signal and I suspect both signals will go up and down proportionally with adjustment of the amplifier gain. No response from the eBay seller since I emailed him with the link to the PDF document above... Re: Help! 12v LED downlight globes = TV interference 18Mar 31, 2010 6:34 pm ended up a jaycar today to get the ferrite chokes and whilst buying them the sales assistant was very sincere in suggesting that I was barking up the wrong tree and what I should be doing is just earthing the antenna as he says this is a common issue with digital TVs and the solution is earthing so will try that because the ferrite chokes didn't help Re: Help! 12v LED downlight globes = TV interference 19Mar 31, 2010 7:37 pm This is some great info guys! Re: Help! 12v LED downlight globes = TV interference 20Mar 31, 2010 8:36 pm I would be interested to see the response from reducing the gain. There is a small possibily that the amplifier is going into current limiting if it is picking up to much signal meaning that all the signal in the band is not being amplified correctly. This is a stab int he dark as you should always get rid of the source first. Hi there, long-time lurker but first time posting. I've bought a house 2 and a bit years ago and last year we had some major water damage on a converted pergola area… 0 7889 Yes, unless you are in a low intensity rainfall area or the area is protected from rain. Do you have access to NCC Part 2 or can you download it? I can email you a copy… 10 12376 |