Aboutcleggsan Expertise All technical areas of Electronics Engineering.
Experience BSEE, MBA, Design, R&D, University Research.
Senior Life Member of IEEE. Life Fellow of AES.
Organizations IEEE, Consumer Electronics Society, Audio Engineering Society.
Broad teaching experience; work experience mostly in consumer electronics and conversion from analog to digital technologies. Pioneer in digital audio at all levels.
Question I received an electrical vibrating chair pad for Christmas. The problem is when it's on; it interferes with the TV, A slight static sound and lines in the picture. How can I correct this?
Happy Holidays,
Randy
Answer Try moving it into other positions or orientations, but appliances of this kind that put out rf fields are hard to contain.
You can try putting on a suppressor which you can get at places like Radio Shack (it plugs into the wall outlet and the cord of the pad will plug into it), but, again, there is only a 50/50 chance it will arrest the problem. There are also suppressors that can be put at the input of your tv antenna or cable connection, but I give them a 50/50 chance, as well.
Normally, in these kinds of interference cases it requires some trial and error experimentation to get to the bottom of it (no pun intended).
Small manufacturers usually donot have the engineering manpower and skill to design the interference out of their products like the big ones do. A Sony or GE appliance of this kind would have been tested and perfected for interference, I think.
Hope this helps, but my experience for these kinds of problems indicates it will be an uphill battle.
(Electrically speaking, the vibrating pad has an electronic switch that regulates the speed or intensity. The switch is a UJT or FET or something like that which switches fast enough to create a burst of high frequency energy each time it switches - which is every cycle of the 60 cycle line frequency. That is what creates the lines and the static field. This rfi field is induced into the tv - probably directly into the circuitry via air transmission - and maybe through the power line as well. If you try a portable radio nearby the pad you will probably get similar horrible sounding interferfence because the spectrum of the switching components is wide range. A good manufacturer would have designed the switching circuit to be more gentle in its characteristic and/or added shielding to keep the radiating energy contained.)
Very best wishes. Have a great holiday season. Thanks for sending in your question.
