Did site electrics blow my laptop

[ScouseIan]

I have just returned from El Delfin Verde on Costa Brava. The power adapter for my laptop has worked seamlessly for the past 2 years and it chose this location to pack up. I thought nothing of it and simply ordered another one which was there when I returned home.

Upon discussing this with someone today they suggested it may have been a surge on the site electrics that caused this to happen.

My questions are

1. Is this feasible?

and

2. Wouldn't it have damaged the caravan 'lectrics?

I suppose I could buy a Surge Protector to ensure it doesn't happen again

 

[rob_jax]

Ian,

The switched mode power supplies used with laptops don't last for ever - my Sony laptop power pack failed over a period of months - the laptop gave an indication that the battery pack was failing but that turned out to be merely a symptom of the power pack dying...

As to a spike causing it to fail - then yes - that is a possibility, but most devices are capable of handling 25% over-voltage without issue - and any more than that will cause a cascade of problems throughout the caravan.

Surge protector? Probably not the protection you think they'll give - they work by redirecting over-voltage to the return line - and the cheap surge protectors have a trip set at 450 V - roughly x2 normal voltage. So the damage will already be done before they trip.

Likewise they have a maximum operating life - and they only provide protection for a fraction of a second - otherwise they then work like a fuse. They'll possibly provide protection against a very short, high voltage spike - but not a constant over-voltage...

Robert

 

[Stephen_374341239]

IAN

My Laptop power adaptor went U/S. Got one on E Bay third of the price then in the shops and is still working.

 

[RogerL]

A surge protector is vital for any sensitive equipment - they're recommended for UK mains supply as well as other areas where the supply is less reliable.

 

[rob_jax]

Hi Roger,

I'm going to disagree and agree.

The "cheap" home surge protectors are cheap because the varistors (the component that dumps the surge) used are high voltage, low power variants - this has the benefit of cheaper components and they last longer because they don't trigger that often.

But a good quality surge protector will use a high power varistor that clamps at a significantly lower voltage - and that means a shorter life.

The high power (more than 1000 joules) rating means these can handle the damaging spikes - the home office type are often rated below 200 joules and that's not enough protection.

So yes, a surge protector is a good idea - but the low cost home office grade of devices aren't really up to the job.

Robert

 

[Legsmaniac_374344731]

Hi rob_jax

I'm going to disagree and disagree.

The Belkin range of surge protectors for example do exactly what they are designed to do. Should they fail, they have a lifetime guarantee and a promise that they will cover and replace your damaged equipment caused by surge whilst protected. Whoever told you that they trip at 450 volts is just ridiculous.

That said, I doubt it was a surge that blew the laptop PSU and was "just one of those things".

 

[rob_jax]

Hi,

It's not ridiculous - it's a fact - look up the specifications for MOS Varistors and their suggested application.

Robert

 

[RogerP]

Hi Ian

you dont state what type of Laptop you have.

I've used laptops for many years now and my current IBM which is about 2 years old is on its 3rd power pack (as are others in my company not just mine).

Previous to that I had a Compaq which never lost its power pack in 8+ years of use. In fact its still in a cupboard at work and (without boring you) we needed to fire it up a couple of weeks ago and it all still worked.

My (conspiracy) theory is that things are being desgined to last shorter lives so we have to buy new more frequently

 

[gary]

Some confusion between 'surge' current and 'spike' voltage protection, at least as far as simple power supplies for laptops, caravan battery charging, TV's and many more applications.

All are equipped with their own inbuilt current and voltage protection to prevent fire at the very least.

Surge can be caused by outside influence, (lightning strike), more often though by the appliance itself, for this protection a temperature dependent resistor is used.

Cold the resistor has a resistance of perhaps 14ohms, this resistance creates heat and this heat reduces the resistance to zero over a few seconds. Result is the current demand of the appliance is fed in gently and does not put undue strain on the power supply as a whole. Soft start on motor moves works in a similar way and is for that purpose, not to make your life easy!

Spikes are always due to outside sources, the protection for this is a voltage dependent resistor and these are connected between the live supply and neutral return, the 'clamp' voltage for a 230v to x volt power supply is 275v at which point the infinite resistance across the component reduces to zero providing a 'dead' short.

Both these components work in conjunction with a fuse, this is of the timed variety and generally T2A or T3.15A (3amps for 1.5 seconds)

If then a current surge tries to get through to fast the resistance cannot drop fast enough and the time exceeds the fuses ability to withstand that current.

Similarly, if a voltage spikes over 275v then the dead short this creates will instantly blow the fuse.