BS: TV remote: fire hazard?

Subject: BS: TV remote: fire hazard?
From: Steve Parkes
Date: 22 Aug 03 - 03:42 AM

There's an entertaining piece in this week's New Scientist mag (see below). I remember hearing or reading a news item ine recent years about a fire started when a tv remote control slipped down the side of a sofa and overheated when the buttons were pressed, but there doesn't seem to be any record of it now. Does anyone else remember this?

Steve


DO YOU ever wonder how folklore factoids - like the giant alligators in New York's sewers - are born, and end up as questions on New Scientist's Last Word page?

Firetech, a British fire safety company, has been sending the press "invaluable advice" with the explicit warning that a "cause of fires in the home is the TV remote control - this slides down the sofa and a button gets pressed and this can catch fire". As we spend half our life hunting for lost remote controls, we asked whether the wayward remote turns on the TV, which then bursts into flames, or whether the remote itself ignites? A spokeswoman helpfully explained: "When it falls down the side of the sofa or armchair, one of the buttons gets pressed and stays pressed, and this causes the remote to catch fire."

Worried and intrigued, we asked if there was any documented evidence of a fire starting this way. Says Firetech's Trevor Dean, a former fire officer: "I cannot give you any examples at this point." But he was able to refer us to a 1996 report from the British government (www.dti.gov.uk/ homesafetynetwork/pdf/tvfires.pdf). Unfortunately, this report says nothing about flaming remotes. It just reassures that if there was once a risk of TV sets self-combusting while standing by for remote control commands, this was no longer a problem with new sets, even in 1996.

Says Dean: "It depends on how you read it."
(New Scientist, "Feedback", 23 Aug 2003)

Subject: RE: BS: TV remote: fire hazard?
From: Steve Parkes
Date: 22 Aug 03 - 05:19 AM

I suppose I could have out this under "Folklore", as it seems to be an urban myth now.

Subject: RE: BS: TV remote: fire hazard?
From: Amos
Date: 22 Aug 03 - 09:32 AM

I have never heard of such a thing. And considering how much heat is available I'd say it is highly improbable. Do the math.

A

Subject: RE: BS: TV remote: fire hazard?
From: Steve Parkes
Date: 22 Aug 03 - 09:46 AM

Amos, if you short a 1.5 volt cell -- even a little AAA type like you often get in these things -- through a strand of copper wire, you'll see it get red- or even white-hot in a second (and probably burn your fingers pretty badly); think of a torch bulb. You can scale the temperature down a bit for the currents that run through a remote (and a modern one won't be a danger anyway), but bear in mind they are only intended to operate in short bursts of under a second for each keypress. If you hold a key down for a long time the temperature will have time to increase, and I can easily believe that the early ones could get pretty warm. We're talking about a closely confined space between two heat-insulating flammable objects (non-fire resistant seat cushions), where the temp can build quite a lot. Bear in mind too that any domestic fires start from things that smoulder for a long time at a relatively low temperature before the heat can build up to combustion point.

Sorry about the lecture! All Ireaaly want isfor someoe to tell me I didn't dream it, it realy was on the news.

Steve

Subject: RE: BS: TV remote: fire hazard?
From: Amos
Date: 22 Aug 03 - 10:25 AM

Ibelieve the earlier remotres used larger batteries, as well. So maybe so. Not likely now, though.

A

Subject: RE: BS: TV remote: fire hazard?
From: NicoleC
Date: 22 Aug 03 - 12:50 PM

It kinda of reminds me of learning the hard way not to walk around with 9v batteries in the pocket of your jeans.

Subject: RE: BS: TV remote: fire hazard?
From: MarkS
Date: 22 Aug 03 - 01:53 PM

OOOOOOOOOH! Nicole C - Your post conjured up images I sure do NOT want to dwell on!!!
Mark

Subject: RE: BS: TV remote: fire hazard?
From: nutty
Date: 23 Aug 03 - 12:46 PM

I once put the batteries, into a remote, the wrong way round and it started to get very hot. I've no doubt that, had it been left, it could have started a fire

Subject: RE: BS: TV remote: fire hazard?
From: Rapparee
Date: 23 Aug 03 - 10:28 PM

I learned the hard way not to check whether a 9-volt battery still has juice in it with your tongue.

Subject: RE: BS: TV remote: fire hazard?
From: Stilly River Sage
Date: 23 Aug 03 - 10:35 PM

Radio Shack sells a very nice little battery checker that works on a variety of small household batteries, including 9-volt.

SRS

Subject: RE: BS: TV remote: fire hazard?
From: Steve Parkes
Date: 26 Aug 03 - 03:57 AM

I'm surprised Roger the Skiffler hasn't beasten me to it, but I have my grandad's old Ever Ready portable radio: it's about thesize of a quite small attache case, complete with handle; to turn it on, you open the lid (which contains the loop aerial). It had two batteries: a 1.5V for the valve (US: tube) heaters, and a 90 -- yes, ninety V for the main power. They heater battery comprised about six C-size cells (Ever Ready size U2) soldered together, in a card container with a little socket on top to plug the heater lead into. The 90V job was even bigger; it was made up of lots and ts of those littel flat cels ypu find in you take a 9V battery apart. You can get a shock from around 70V, so it wasnt a good idea to take one of those apart! The two cost (I think) around two or three pounds back in the sixties; that would be maybe £10-£15 today? They lasted a long time, though. Around 1970, someone gave me a mains adaptor, designed to power valve portables; a good job, because you can't get the batteries any more.

Roger will no doubt give us some reminiscences about taking the accumulators to be charged...!

Steve

Subject: RE: BS: TV remote: fire hazard?
From: Dave Bryant
Date: 26 Aug 03 - 05:32 AM

I think that an alkaline AAA cell has a capacity of about 1 amp hour.
Therefore if there are two of them, the total amount of energy is 3 watt hours. While these could, if short-circuited (especially if they were connected in parallel as this would reduce the internal resistance) produce enough heat to set something alight, I would think that the normal load would hardly be enough to produce enough heat to do any damage. Most semi-conductors which produce any heat are normally mounted on heatsinks which tend to disperse it and I'd be surprised if there are any resisters less than about 100 ohms to heat up (3v across 100 ohm would produce less than 1 watt - the heat of a torch bulb).            

Incidently Steve, I used to have a battery-powered valve radio which worked on a single battery which produced both a 1.5v heater supply and a 67.5v anode supply. There were whole families of valves made for these things and my first amplifier was based on battery valves as my dad wouldn't let me use mains power until I was older.

Subject: RE: BS: TV remote: fire hazard?
From: Rapparee
Date: 26 Aug 03 - 08:43 AM

I've used D cell batteries to start fires when I didn't have a match. Twist the ends of some steel wool (the finer the better) together and hold it to the ends of the battery (I suggest taping it). It will work, but it plain ruins the battery. Be very careful if you try this.

Subject: RE: BS: TV remote: fire hazard?
From: Steve Parkes
Date: 26 Aug 03 - 09:57 AM

Car batteries are very good (30A+ at nearly 14V), but don't expect one ever to start a car again after you've shorted it!

Subject: RE: BS: TV remote: fire hazard?
From: Roger the Skiffler
Date: 26 Aug 03 - 10:38 AM

I'll ignore young Parkes' incinerations about my venerability. He's just starting this scare story to keep his spouse and offspring away from the remote, which as any fule kno is the proper preserve of the hunter-gatherer male (as is possession of the RadioTimes/TV Guide.)

RtS
("The day war broke out...")