Beware Dodgy Xmas Lights!

Neil · 08-12-2004, 13:20

Quote:

Dodgy Christmas lights are being blamed for knocking over broadband connections with imported flashing lights that don't meet UK electrical standards fingered as the worst offenders.

Source: The Register http://www.theregister.co.uk/2004/12...adband_lights/

Paul K · 08-12-2004, 13:35

Saw that a little while ago, thankfully it's never affected my connection in the past evn though the house in Peterborough looked like a reject from Close encounters of the third kind

Mind you, we never bought cheap lights so that probably helped

**Mick** · 08-12-2004, 14:45

I never buy cheapo ones either - bought some ones that play all the christmas tunes and the lights go along with the song....

themelon · 08-12-2004, 15:03

Well it only affects ADSL by the sounds of it. Oh well!

Must have to be some seriously dodgy lights. Hope none of the major retailers are selling these.

I brought some smartprice lights for about ÃƒÆ’Ã†â€™ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â£4 seem alright

AndrewJ · 08-12-2004, 18:57

You tend to get what you pay for in this country.

08-12-2004, 19:00

thought this was going to be a tacky house light show picture thread

AndrewJ · 08-12-2004, 19:03

LOL I remember hearing once the most commonly broken into homes in Xmas are those with lights everywhere on them.

To the theives its all birthdays in one.

Perfer my Xmas stuff to be indoors and suttle.

Raistlin · 08-12-2004, 19:11

Quote:

Originally Posted by AndrewJames

You tend to get what you pay for in this country.

Unfortunately you don't though - that's the problem.

Theodoric · 08-12-2004, 19:54

Ah.

"When the lighting control unit is set to any mode other than a steady state it may generate high levels of radio frequency noise and may cause the broadband service to lose synchronisation."

Will it? The lights are probably going on and off at about 1Hz. So you've got a squarish wave which can be expressed as as a Fourier series, that is a sum of sin and cos terms of higher and higher harmonics. Does it actually extend to rf frequencies? I suppose it's possible. Fridges switching on and off used to be blamed for interference. I await a reasoned response from an electrical engineer.

Raistlin · 08-12-2004, 19:58

Quote:

Originally Posted by Theodoric

So you've got a squarish wave which can be expressed as as a Fourier series, that is a sum of sin and cos terms of higher and higher harmonics.

I was just about to say that

Theodoric · 08-12-2004, 20:04

Quote:

Originally Posted by Raistlin

I was just about to say that

You were? Sorry I pipped you to the post.

Stuartbe · 08-12-2004, 20:05

It depends as to the type of energy being radiated . All electrical devices create an electo-magnetic field when current flows through them. The CE testing is there to ensure that that radiation is kept to a minimum and devices are suitably sheilded against it. I believe that it is an offence to sell devices that do not meet this standard in europe. If it is radiated rf energy then the low voltage cable from the switched mode transformer to the cable modem can pick this up like a mini anttena. A ferite ring wound around the cable can help supres this.

Since the coax cable on the modem would filter the majority of rf interference the most likely source is reflected rf noise or pulses traveling through the mains system back to the equipment. I decent surge supresor with rf filtering could help stop this happening. After all everyone should have a surge supresor/filter as an absolute minimum, A UPS would be even better

It would be interesting to get a set of these dodgey lights and watch the mains supply on a fast sample scope for pulses or noise. The srarp increase and decrease of current that is drawn could well create pulses that cause the problem....

If the problem ocurs when the lights are some distance away then I would go with the noise/pulses down the mains supply theory.

HTH.

Alanmelon · 08-12-2004, 22:02

Say wha'..........?!

dilli-theclaw · 08-12-2004, 22:06

Quote:

Originally Posted by Stuartbe

It depends as to the type of energy being radiated . All electrical devices create an electo-magnetic field when current flows through them. The CE testing is there to ensure that that radiation is kept to a minimum and devices are suitably sheilded against it. I believe that it is an offence to sell devices that do not meet this standard in europe. If it is radiated rf energy then the low voltage cable from the switched mode transformer to the cable modem can pick this up like a mini anttena. A ferite ring wound around the cable can help supres this.

Since the coax cable on the modem would filter the majority of rf interference the most likely source is reflected rf noise or pulses traveling through the mains system back to the equipment. I decent surge supresor with rf filtering could help stop this happening. After all everyone should have a surge supresor/filter as an absolute minimum, A UPS would be even better

It would be interesting to get a set of these dodgey lights and watch the mains supply on a fast sample scope for pulses or noise. The srarp increase and decrease of current that is drawn could well create pulses that cause the problem....

If the problem ocurs when the lights are some distance away then I would go with the noise/pulses down the mains supply theory.

HTH.

Yeah - thanks for all that.
I'd respond - but my brain hurts now....

All my electrical stuff in the house is running through a surge protector is that helps?

Yours confusedly

Dilligaf

danielf · 08-12-2004, 22:36

Quote:

Originally Posted by Stuartbe

<snip>
It would be interesting to get a set of these dodgey lights and watch the mains supply on a fast sample scope for pulses or noise. The srarp increase and decrease of current that is drawn could well create pulses that cause the problem....

If the problem ocurs when the lights are some distance away then I would go with the noise/pulses down the mains supply theory.

HTH.

Hmm, very interesting, if you're into that sort of thing