📨 Have you signed up to the Forum's new Email Digest yet? Get a selection of trending threads sent straight to your inbox daily, weekly or monthly!

why does the tv transmit infra red

Options
i bought a new lcd flat screen sony tv. nice. but as soon as it is switched on a nearby digital clock, about 1.5 metres away, starts going berzerk, the time keeps changing, the alarm on led flashes on/off etc...

the only way i could stop this was to block the infra red sensor/receiver on the clock.

in case it was the tv remote i took batteries out remote and it still happened.

Is this normal?

My concern is this:
The tv is sending out signals, what are these infra red signals for, what is there target?
the tv should be sending out infra red signals, but only have a receiver for its remote.
would these almost continuous signals being sent out have adverse effects on health or any other hardware nearby?

any one else have this prob?
Hi, we’ve had to remove your signature. If you’re not sure why please read the forum rules or email the forum team if you’re still unsure - MSE ForumTeam

Comments

  • aerostar
    aerostar Posts: 1,738 Forumite
    Part of the Furniture 1,000 Posts Name Dropper Combo Breaker
    Infra red is heat radiation, you body even puts out infra red radiation, what is happening is that the leds that do your display/backlight are constantly being pulsed on and off, your clock is picking this up and probably because the infrared receiver/decode system in it is of poor quality, it is reacting to the signals.

    Not a lot you can do about it but to mask the sensor in the clock.

    There were infra red headphones a few years ago, but if you walked under or near a fluorescent light, you just heard a buzz. Similar effect.

    The infrared is not dangerous to you or other hardware.
  • S0litaire
    S0litaire Posts: 3,535 Forumite
    Part of the Furniture 1,000 Posts Combo Breaker
    what's the make and model of the TV?
    Laters

    Sol

    "Have you found the secrets of the universe? Asked Zebade "I'm sure I left them here somewhere"
  • Spank
    Spank Posts: 1,751 Forumite
    Tenth Anniversary 1,000 Posts Photogenic Name Dropper
    It's the presence sensor, if there's no movement after awhile i switches off the picture
  • rafhelp
    rafhelp Posts: 365 Forumite
    Part of the Furniture 100 Posts Name Dropper Combo Breaker
    sony, i know it has a light/ambience sensor
    Hi, we’ve had to remove your signature. If you’re not sure why please read the forum rules or email the forum team if you’re still unsure - MSE ForumTeam
  • Joe_Bloggs
    Joe_Bloggs Posts: 4,535 Forumite
    Congratulations are deserved for isolating the cause of the problem.
    Are there any guidelines as to what infra-red radiation TVs typically radiate.

    It would take a photo diode, resistor and oscilloscope to find out.

    The LED illuminated LCD screens probably use pulse width modulation to vary the brightness.

    J_B.
  • closed
    closed Posts: 10,886 Forumite
    which clock has the infra red sensor, and what's it for? Same socket?
    !!
    > . !!!! ----> .
  • rafhelp
    rafhelp Posts: 365 Forumite
    Part of the Furniture 100 Posts Name Dropper Combo Breaker
    digital clock. different socket. the clock tells you what time it is the whole day long..
    Hi, we’ve had to remove your signature. If you’re not sure why please read the forum rules or email the forum team if you’re still unsure - MSE ForumTeam
  • closed
    closed Posts: 10,886 Forumite
    edited 17 September 2011 at 3:27AM
    rafhelp wrote: »

    the only way i could stop this was to block the infra red sensor/receiver on the clock.

    I've seen those time keeping devices before, but never seen one with an infra red sensor/receiver or infra red receiver decode system - so if that's correct and your clock has such a sensor, what's it for (auto dimming, remote control, movement sensor, something else), and which clock is it?
    !!
    > . !!!! ----> .
  • if its a 3D tv then you may be seeing the active shutter sync signal ...
This discussion has been closed.
Meet your Ambassadors

🚀 Getting Started

Hi new member!

Our Getting Started Guide will help you get the most out of the Forum

Categories

  • All Categories
  • 351.1K Banking & Borrowing
  • 253.1K Reduce Debt & Boost Income
  • 453.6K Spending & Discounts
  • 244.1K Work, Benefits & Business
  • 599K Mortgages, Homes & Bills
  • 177K Life & Family
  • 257.4K Travel & Transport
  • 1.5M Hobbies & Leisure
  • 16.1K Discuss & Feedback
  • 37.6K Read-Only Boards

Is this how you want to be seen?

We see you are using a default avatar. It takes only a few seconds to pick a picture.