Arial lead to earth voltage

kthomas7 · Posted: Sat Nov 18, 2006 2:21 pm Post Subject: Arial lead to earth voltage

If I measure with a multi meter from earth to my aerial lead I get a voltage varies between 10v and 80v depandant on how mant TV’s are switched on. All TV\\\'s are connected to the same aerial distribution. But TV’s are on a different ring main, I can even measure a voltage to the gas pipes!!! Any idea what the problem is? somthing seems wrong.

Big_Spark · Posted: Sat Nov 18, 2006 2:41 pm Post Subject:

Nothing is wrong, this is perfectly normal as there is always some leakage to true Earth from TV tuners. nature of the beast.

Further, you will be able to measure a voltage from the main aerial lead to true earth if you check..that is why voltage is called Potential difference..it is the potential charge difference between two electrically conductive points, material etc.

Nothing to worry about at all.

__________________
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kthomas7 · Posted: Sat Nov 18, 2006 8:10 pm Post Subject:

Thanks for your comment. But it is enough to give a small electric shock. How do large multi TV setups get over this like TV shops. Where they could get some very high voltages. This voltage is also evident on Audio interconnecting leads on the surround sound amp!

It seams if I can get a electric shock (how I discovered it) I should be worried?

GaryB · Posted: Sat Nov 18, 2006 8:37 pm Post Subject:

As Big_Spark says, this is normal. It happens on any double insulated appliance and is caused by very slight leakage through the capacitors that are present to ensure EMC (Electromagnetic Compatibility) compliance. As you've noticed, the current is tiny and is only usually measurable with a high impedance meter. It's an induced voltage - basically leakage, and is a tiny current and not dangerous.

I work for a TV/VCR/Camcorder manufacturer and we get regular calls about it.

Take a look at:
http://www.unitechelectronics.com/sparks.htm