How dangerous is a laptop charger?

McGraw · 24-01-2009, 13:51

Hi.

Strange question I know but I have a couple of reasons for asking and they both revolve our 12 week old kitten.

We have two laptops, one is new and I've caught her chewing the wire a couple of times.

The other one is really old, slow and has been patched together numerous times but is still useful for web browsing.

Before Xmas, the pin connector inside the laptop snapped off. I shoved some foil in the power adapter and superglued the connection shut (the battery only lasts 8 mins on full charge). It works fine.

However, I'm very reluctant to use it as if the superglue connection was to break, there would be a touchable metal connection coming from the power supply.

What's the risk to humans and cats alike?

Thanks a lot.

Delta Whiskey · 24-01-2009, 14:22

I had a friend who was in a band in the 1970's. He did the same thing with tin foil on his amplifiers power supply cable, one day it short circuited, the next time he touched it killed him.

xpod · 24-01-2009, 14:23

The cat has 9 lives so should be ok for a few shocks but not so sure about you

I`ve superglued broken DC Jacks back onto laptop motherboards without problems but i dont like the sound of your tinfoil

Stuart · 24-01-2009, 14:25

Quote:

Originally Posted by Delta Whiskey

I had a friend who was in a band in the 1970's. He did the same thing with tin foil on his amplifiers power supply cable, one day it short circuited, the next time he touched it killed him.

Although that was probably mains electricity.

McGraw · 24-01-2009, 15:00

Quote:

Originally Posted by Stuart C

Although that was probably mains electricity.

That's what I mean, it's DC output so should be ok shouldn't it?

p.s. the tinfoil is rolled into a very tight cylinder so it's not wafer thin or anything.

Jon T · 24-01-2009, 15:28

Quote:

Originally Posted by McGraw

That's what I mean, it's DC output so should be ok shouldn't it?

p.s. the tinfoil is rolled into a very tight cylinder so it's not wafer thin or anything.

The fact that it's DC might actually make it worse. DC current passing through you(or the cat's) body will either

a) Make muscles contract, therefore making it impossible to remove youself(or the cat to remove itself) from the cause of the shock.

or

b) Fling you(or the cat) along the room, maybe causing more damage than the original electric shock.

24-01-2009, 15:32

I thought AC current flung you away and DC current kept you stuck? (not claiming I know btw)

Jon T · 24-01-2009, 15:44

Quote:

Originally Posted by zinglebarb

I thought AC current flung you away and DC current kept you stuck? (not claiming I know btw)

AC will normally fling you way

With DC it depends what muscles the current is flowing through, Some muscles are in groups of two, one called the flexor that closes the joint, and one called an extensor that opens the joint.

Edit: Just found this: http://www.pat-testing.info/electric-shock.htm so I suppose what i've put above isn't quite correct.

fireman328 · 24-01-2009, 16:29

Just give me a call when the fire starts, and the insurance wont pay out on your smouldering house.
As the old saying goes "its volts that jolts but mills that kills"

Delta Whiskey · 24-01-2009, 16:45

Quote:

Originally Posted by Stuart C

Although that was probably mains electricity.

Yes it was. A short in the laptop could cause a problem in the power pack causing it to fail perhaps putting mains voltage through to the laptop. Hopefully the fuse will blow, but are you sure there is a 3amp or less fuse in there?.

While fixing a set of DJ mixer/turntables, I plugged a microphone into the mic in socket and was thrown across the room (luckily I pulled the cable out as I went). Later inspection showed that a dead short on the transformer was sending 240volts through the whole system. I was dammed lucky.

Kymmy · 24-01-2009, 16:51

It also depends greatly on whether the PSU is a standard regulated model (i.e. transformer, rectifier, smoothing and then a regulator IC) or a switch mode PSU...

Switch mode regulates the AC input (so 230VAC becomes more like 400VDC which is then sent through another oscilation circuit that chops the waveform to give you the lower voltage... (yes I know it's not quite right but trying to keep it simple)...What it does mean though is that on a switch mode PSU if anything overheats or shorts out there's a great chance of the output voltage spiking to a lot higher than on a standard regulated PSU... I believe that 95% of laptop PSU's are of this type as they are smaller formfactor for the range of current they can handle

Oh and on the arguement of AC/DC shocks the DC is more dangerous than the same AC voltage as DC will cause more extensive burning..

Stuart · 24-01-2009, 16:53

Quote:

Originally Posted by McGraw

That's what I mean, it's DC output so should be ok shouldn't it?

p.s. the tinfoil is rolled into a very tight cylinder so it's not wafer thin or anything.

TBH, I wouldn't risk it. Even if no one is electrocuted, there is still a risk it could catch fire

I'd buy a Universal power supply such as http://www.amazon.co.uk/Universal-La.../dp/B000KBAO7I

McGraw · 24-01-2009, 17:43

Thanks, I'll probably leave it

rogerdraig · 24-01-2009, 18:41

from the 12 to 18 volts not much but any intermittent short could cause problems for the converter which if it over heats could cause you problems

do you know any one handy with a soldering iron ? as putting a new power socket on a laptop isn't that hard ( other than having to take the thing apart anyhow lol )

the one i am on now has had to have that done

i am even tempted to suggest that you get them to ( as i am doing the next time i need to do this ) to attach a cable to the board and use an external socket as most damage i see is from tilting laptop with supply in and not from pulling the cord out accidentally

24-01-2009, 21:23

Why take the risk - just bloody buy a new adapter!!!