I have been enjoying changing my lighting over to LED. However, I have now discovered the downlight replacements to LED, from 12V halogen (MR16), is causing interference of DIgital TV reception. The RF noise may be coming from the transformers being under powered. Anybody else suffering from, or overcome, this problem?
LED Lighting
(136 posts) (40 voices)-
rsigmund
MemberAre you certain of the type of voltage regulator you are using?
.....
Transfomer type - Heavy
Switch Mode type - light (most mobile phone chargers are this type)
It would seem a bit strange for a transformer to produce UHF interfernce from 50 Hz
Rod.
Posted Tuesday 25 Nov 2008 @ 1:16:20 am from IP # -
photomac
MemberThanks,
If I turn the downlights off the interference disappears. Analogue on a different TV is affected. I went to a ligting store and they had transformers specifically designed for LEDs and up to the 50w rating if an halogen is reinstalled. I am yet to install the new "transformers" - the manhole is surrounded by aircon ducts and Im not a Houdini
An access hole via an end gable has been initiated - lol - how little jobs grow!
CheersPosted Thursday 4 Dec 2008 @ 8:50:14 am from IP # -
Inspector
MemberI searched for this topic before but the forum was down, so I created a new thread on another forum (with no suitable replies as yet)...
I have experienced the same symptoms as the creator of this topic.
Analog TV reception has two fuzzy horizontal bars across the screen when the 12v LED lights are turned on. Digital reception becomes very blocky and no sound, or completely blanks out, regardless of whether it's the living room TV or the USB DVB-T tuner card in the PC, at the other end of the house! Channel 7 stations tend to be the worst affected, while channel 9 stations seem almost unaffected (unless I have all seven globes turned on).
Some things I have tried to eliminate the problem include wiring all seven globes from one transformer, and even changing the lighting circuit to a different phase at the switchboard, in case the transformer was causing "feedback" on the phase used by the power circuits running the TV and the TV-antenna amplifier.
Other testing I did was to wire up a transformer using a 3-pin plug lead for supply, and two 12v LED globes running off the output, so I could carry it around and test in various power points. I found that holding the globes and transformer in specific angles caused the interference in TV reception. Interestingly, plugging this "tester" into the power point in the room behind the TV didn't cause any interference, however plugging it into the power point in the room directly above the TV-antenna amplifier caused lots of interference.
I have tried two different brand electronic transformers, which had the same affect, and I was going to try an old iron-core transformer, but I don't think that would make any difference.
I have four GU10 240v versions of the same LED globe in the kitchen, and they don't seem to have any affect on the TV. My next step will be to make up a tester with 240v globes instead of the 12v globes, to see if they cause interference at different locations in the house (particularly the lounge room). If they work, I'll try and exchange the MR16's with GU10's with the eBay seller.
There's no way I could afford seven "brand name" $200 LED fittings - and be sure they wouldn't have the same problem!
Posted Monday 29 Mar 2010 @ 6:27:11 am from IP # -
Inspector
MemberUpdate:
The torroidal transformer made no difference; the interference is still present with only two 12v LED globes connected to it.
I bought four GU10 globe-holders from the wholesaler, and with four globes fitted, there was no interference whatsoever, so that is a success.
It was also suggested on the other forum that I try winding down the gain on the TV-antenna amplifier, but I don't think it'll make any difference, as the interfering signal is probably already stronger than the TV-station broadcast signal (due to proximity ti amplifier) and I suspect both signals will go up and down proportionally with adjustment of the amplifier gain.
The following link was provided in the other forum which might be suitable for anyone else wishing to claim a refund or persue the matter further with relevant government department (Fair Trading?)... http://www.acma.gov.au/webwr/_assets/ma ... 20fs35.pdf
Posted Wednesday 31 Mar 2010 @ 8:34:30 am from IP # -
Inspector
MemberI replaced all cabling with new, and it has helped somewhat, but still not perfect. I now get channel 9 without interference when five 12v LED globes are turned on, and channel 7 is jittery (better than the blank screen I got before).
I also bypassed the amplifier and disconnected all other leads from the splitter box so the main TV was the only one connected directly to the antenna, and that made no difference either.
Contemplating which is better option: to relocate the antenna to a point on the house further away from the globes (as new cabling seems to have helped), or replace the 12v LED globes with 240v LED globes which would require rewiring that section of the circuit (the existing wiring will not reach far enough as it was made exact-length to loop in and out of transformer terminals).
Does anyone know if regular antenna installers carry a device to measure interference levels?
Posted Thursday 8 Apr 2010 @ 10:19:45 am from IP # -
The Antenna Handbook from Digital TV Switchover Australia provides good information on installation standards. On pages 25 - 30 they have a check list and signal measurement information. Pixelation from impulse noise generated by all sorts of devices is one of the weak spots of digital reception.
http://www.digitalready.gov.au/publications.aspx
General TV reception advice is available from the Better TV and Radio Reception Handbook.
http://www.acma.gov.au/WEB/STANDARD/pc=PC_300044
Page 5 of the Consider Digital document refers to impulse noise.
Posted Wednesday 21 Apr 2010 @ 10:31:15 pm from IP # -
LanceTurner
Key MasterThe problem isn't electrical noise in the wiring getting into the TV etc via the mains wiring, what happens is that electronic devices, such as the switchmode drivers inside the LED bulbs, will emit noise into their supply wires which then act as antennas, so it affects reception by swamping the TV signals.
New cabling on the TV leads will help a bit as it will probably have better shielding than the old cable, but the trick is to stop the noise getting into the bulb supply wires.
There's a few ways to do this, including putting a small value capacitor, say a 10nF, across each socket, as well as clipping an RF suppression bead on each supply wire close to the bulb socket. You get these from mobs like jaycar etc, they are just a 2 part ferrite bead in a clip together plastic case. You see this sort of suppression on laptop power cables and other devices that use switchmode supplies to drive sensitive electronics. The barrel shaped lump in the cable is a suppression bead...
Posted Thursday 22 Apr 2010 @ 12:27:07 am from IP # -
ahhhh ... I have the same problem. I installed 3 LED 12V downlights in my kitchen. Was just playing around with it to try to save some money in the house and get my electricity usage down. My TV was affected when the LED lights are on ... (lights off = TV works ... lights on ... nothing works).
@Lance: I understand the ferrite bead ... easy to install. But this capacitor ... mhhh... sounds complicated ... thanks for these tipps.
Posted Thursday 22 Apr 2010 @ 10:48:35 am from IP # -
alfresco24
Member1. Could you name the LED globes in question?
2. Can you test the LED globe separately?
The conducted radiation and re-transmission interference through home wiring is a real consideration, but the noise may not come about if the LED globe is driven properly.
(It's no excuse for LED globes being sold that are so obviously vulnerable)
Can someone take one of their problem globes and connect it to a battery and move it to and away from TV's, tuners and antenna cables. If the globes emit enough interference to be visible under these conditions then the LED globes are CRAP.
If you're using a 'transformer' that is really a small switch-mode power supply (SMPS) to drive the LED globes then it will also inject some noise back into the power line and Yes, low load does change the frequency and period of the charge circuit in those SMPS (some good some terrible). This noise might also couple with the LED globe itself which often contains its own current management circuit (some good some poor) as well.
Try using a 'real' transformer with smooth linear DC power supply. If that still makes TV signals fuzzy then you're on your own;)Posted Friday 23 Apr 2010 @ 3:59:13 am from IP # -
Inspector
MemberSuch a pity I didn't keep one of the globes or think of the battery test before I sent them all back last week!
I am 95% sure it is EMITTED noise, as I can affect the TV reception by moving the globe and transformer around - some angles cause interference, while other combinations of angles cause it to go away (globe AND transformer need to be in the correct direction for the interference to go away). See my post earlier in this thread a few weeks ago.
I tried these combination directional tests with the electronic transformer, but not with toroidal transformer. Regardless, if it was electronics injecting back into the house wiring, the direction of the transformer or globes would have no affect on this.
Posted Friday 23 Apr 2010 @ 4:18:47 am from IP # -
GBD - can you let us know which LED brand you are using and confirm that they are 12volt (as these seem to be the LEDs that interfere with TV reception)?
Posted Tuesday 8 Jun 2010 @ 3:09:59 am from IP # -
I just purchased a 240V 3W LED Reflector GU10 MV 45deg lamp from Woolworths for $6.98 on special this week. It is a 2800K Warm white 110 lumens. They have the 12V version for $12.98 as well. About time the prices were more in line with their value.
I'll hook it up and see if it looks any good.
Posted Tuesday 8 Jun 2010 @ 11:49:19 pm from IP # -
LanceTurner
Key MasterYou get what you pay for, 110 lumens from 3 watts is well under 40 lumens per watt, not exactly great efficacy compared to current standards which are up around 3 times that. You get what you pay for, but low output lamps like those are going to give LED bulbs a bad name...
Posted Wednesday 9 Jun 2010 @ 12:57:28 am from IP # -
I just hooked it up Lance and I must say I am impressed. The light is very nice and the 45 deg angle is quite impressive. Couldn't look into it as it is so bright. Barely warm after 15min running. I'm off to clean out the shelf as there was only a few left.
My friend has been buying the Jaycar $39.90 ones and I will do a side by side comparo tomorrow. Having seen his I think for an extra $33 mine is very close and is definitely better value. As for getting what you pay for, this is the same argument against cheaper chinese modules and it doesn't stand up in reality.
Update: After one hour they are hotter but still able to be held. And just under 40 lumens / watt at 36.666/W.
Posted Wednesday 9 Jun 2010 @ 1:07:40 am from IP # -
LanceTurner
Key MasterOh, I'm not saying they aren't good value, but a 50 watt halogen replacement they aren't, not even close. That's what people will be looking at them for, there's no reason they couldn't have used a better LED than the one they did, even a cheap Cree P4 is only a few $ more and would double the light output.
Sub 40 lumens per watt is really poor by nowadays standards, but maybe they are listing the lamp output lumens, not the LED chip lumens (which is before optic and other design losses), so could be the LEDs are more typical of the current crop of chinese LEDs at around 60 L/W. I might have to grab one of these with my next trip to woolies...
Posted Wednesday 9 Jun 2010 @ 2:23:43 am from IP # -
I suspected the rating may also be a bit low but it also states they are 20W equivalents not 50W so there is no misleading claim. I could put 6 of these in for just over the price of one Jaycar unit so the value is there. Probably great for mood lighting.
Posted Wednesday 9 Jun 2010 @ 2:32:05 am from IP # -
LanceTurner
Key MasterA 20 watt halogen produces around 400 lumens, so that is a bit of a stretch, but they go by lux levels (the LEDs have a narrower beam angle to keep the lux levels equivalent to a 38 degree halogen, but the area the LED lights will be less).
Posted Wednesday 9 Jun 2010 @ 3:59:47 am from IP # -
The Jaycar catalogue shows the 3W warm white CREE at 220 lumens for $59.95 which is still only about half the output of a 20W halogen at 400 lumens. This is about $0.27/lumen for a narrow 38deg. The woolies LED light is about $0.06/lumen with a wider 45deg angle that is closer to a std halogen at 38deg. I suspect a side by side test is going to show only a marginal difference in performance with a massive difference in price.
Edit: the cheaper 60 deg warm white at $34.95 is 100 lumens and looks much better value but is still way overpriced. The warm white GU10 fittings are 100 lumen for $39.95 compared to the 110 lumen woolies for $6.98. More light for a fraction of the cost.
Posted Wednesday 9 Jun 2010 @ 6:05:21 am from IP # -
LanceTurner
Key MasterAh, yes, but who buys LED globes from Jaycar!
Posted Wednesday 9 Jun 2010 @ 6:31:38 am from IP # -
Unfortunately people do and my good friend did. That is what gives alternative technologies a bad reputation, overpricing because of that 'green inner glow' they push in the catalogue right next to the globes, not the product.
It's our job to show members any good choices they stumble across and that's why I posted the woolies special. Next week they will be back up to $12.98.
Posted Wednesday 9 Jun 2010 @ 6:44:57 am from IP # -
LanceTurner
Key MasterThe problem with jaycar is that they have 6 tiers of pricing structure, 3 wholesale (through electus) and 3 retail, so they are always going to be expensive. Their LED prices are just nuts. Other retail stores are similar, you have to go offshore to get good prices in most cases. For instance, have a look at http://www.dealextreme.com/details.dx/sku.39027 , I have this and the cool white version on test here (albeit in a completely open fitting), the cool white has been running 10+ hours a day every week day for around 4 months with no issues, and they are nice and bright.
The biggest problem we have found with many LED bulbs, and virtually all MR16 types, is that their drivers use electrolytic capacitors in them. Because the driver is mounted on the heatsink or close to it, and is above it when the lamps are mounted pointing down, the drivers get hot. This dries out the electros which eventually can't filter the rectified AC properly and the driver ICs either shut down or go bang.
Electros are about the worst type of capacitor you can use in a circuit that experiences regular heating, yet virtually all the manufacturers use them. Most use the higher temp 105 degree types, but this just delays the failure of the driver. In short, you have a LED bulbs where the light source may well last 50,000 hours, but the driver may only last 5000-10,000, kind of pointless really...
Posted Wednesday 9 Jun 2010 @ 6:54:24 am from IP # -
Imagine paying $60-$75 for one that fails just out of warranty. Until the technology improves I'll stick with the $7 woolies ones. I managed to get 9 for $63. Long term testing starts today.
I'll leave one on 24/7 as the leaflet says 30,000 hours or about 3.5 years. The packaging says "We guarantee that if you're not 100% satisfied with this product we will refund you the purchase price at your nearest store." Doesn't talk about a time limit and I reckon they will still be there in 4 years. Can't beat that and no overseas supplier to haggle with.
PS good link
Posted Wednesday 9 Jun 2010 @ 7:16:46 am from IP # -
This site has a good power savings calculator for LEDs vs halogens.
http://www.ledcentral.com.au/online-store?page=shop.browse&category_id=12
Posted Wednesday 9 Jun 2010 @ 8:21:30 am from IP # -
This electrician on Whirlpool reckons CoolMax Led lights are good. Still pricey but 10 packs are lower. Another point of view anyway.
Partial quote "Point 1
Colour comes in a frequency & a temperature range.
Halogens are 2800k & roll down to 2400k as they get older. If this is the colour you like , then you will need to buy a LED globe to come close to this colour temp.3000k is a good start.
Point 2
Most LED globe makers take a small chip & run it hard, hence a heat problem & a high colour temp. (to maximise the amount of light, Lumens)
The hotter a LED runs , the shorter the life,(forget 50,000 hrs)
You are best of getting a bigger chip (9watt) & driving it at 75%.
Lots of light & little heat = long life
Point 3 To get the longest life you need to use GU10 240 volt LED's"http://www.ecosparks.com.au/index.php?cPath=1
http://forums.whirlpool.net.au/forum-replies.cfm?t=1439403&p=4
Posted Wednesday 9 Jun 2010 @ 9:02:56 am from IP #
