Mobile Phones and Computer Temp Sensors

[Bryce W]

Today I was talking to my girlfriend on my mobile phone and I noticed my screens were going crazy because of the disturbance caused by the phone, I wanted to find out which part of the phone causes the disturbance so I started to move the phone around my screens in front of the glass, near the back, around the sides and down below.
It seemed that below the screens it had the most effect so I thought it could have been the cable that it was effecting (as the cable was below the screen). I put the phone near where the cable goes into the screen - no effect, I moved the phone to the middle of the cable - no effect, I put the mobile phone near where the screen plugs into the case and alarms start going off, this happened:


http://www.knuckles10.com/files/ComputerHeatWTF2.gif


According to the computers heatsensors over the course of 3 seconds it went from 52C, to 72C and then back to 52C. Very Strange…
I am going to try and duplicate this next mobile phonecall I get.


Has anyone else seen or heard of this?

[Stealth]

It's quite a normal effect on electronics. Electromagnetic interference (EMI) can induce a higher current in the sensor, so it detects the wrong value. In ideal circumstances, if it had been oriented the other way you would've detected a slight decrease in temperature.

The same thing happens with the monitor - the coils around the cathode ray tube that focus the light get a higher current circulating through, so the effect is a wobbly screen.

[Bryce W]

The same thing happens with the monitor - the coils around the cathode ray tube that focus the light get a higher current circulating through, so the effect is a wobbly screen.
Ive seen this happen plenty of times to my monitor, Ive known about the effect it has on monitors for a very long time, but I didnt know it would effect a CPU temp sensor.

I wonder if this same thing applies to LCD screens seeing they havent got a cathode. Hmm...

[Kiwwa]

You shouldn't ever see an effect from a mobile on an LCD monitor, there's no way for it to particularly interfere with the display, perhaps the sensor is receptive to, or poorly shielded from EMI...

Who knows :)

[Stealth]

LCDs are usually better encased than CRTs. CRTs are about as shielded as your average TV, which means a plastic outer shell, air, and the cathode tube with coils in the middle. Plastic doesn't hinder the magnetic field much, and neither does air, so of course they're susceptible.