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Thread ID: 95096	2008-11-24 08:52:00	Lights out... TV freezes	pingu45 (13461)	Press F1

Post ID	Timestamp	Content	User
722435	2008-11-24 08:52:00	Ok so I'm watching freeview on my PC. As soon as I turn the desk lamp off, there is a *pop* on the speakers, and the TV feed freezes. Just interested in any explanation... Oh and by the way, could this mean my surge protector is faulty?	pingu45 (13461)
722436	2008-11-24 10:52:00	Hi Pingu45 Your problem is one known in the electronic digital logic world as "Contact Bounce" Basically, what we think is a simply on/off sequence is anything but to electronics. The switch contacts actually bounce, ie switching on and off many times until they finally run out of physical force. This is the pop you hear in the speakers. Now your computer, (and freeview decoder), is just one big electronic digital logic machine and these contact bounces sequences can play havoc. Your computer misinterprets these on-off pulses as a data stream!! With the small amount of voltages/current involved, I think this is a good indication things are working as they should with your surge protector. Generally these need higher amounts of energy to trigger. Ok, what can we do about it? For a start, do not plug the desk light into the same power socket as your computer. Then try spraying a little CRC on the light switch to clean the contacts internally. You might even have to renew the switch. There are electronic methods, (Debouncing Circuits), of solving the problem but I don't really think they are justified here. Excellent article on Contact Bounce HERE (www.allaboutcircuits.com). BURNZEE	Burnzee (6950)
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