# Did my inverter burn out my computer?



## stevensir (Apr 6, 2009)

Hello everyone.

We recently returned from an amazing first motorhoming trip to france. Thanks to all the advice before leaving. 

We took our laptop which is under a year old. Used it loads as the little one watched cbeebies on it whilst traveling. I used a 500w (cheapish) I think (£50) from go outdoors to charge the battery. I used it whilst driving and when stopped. It was connected directly to the leisure battery. I did notice the transformer for the pc hummed a bit louder than it does when plugged in at home. But it worked fine and was plugged in for several hours during our trip. Once we got home I plugged the laptop in as normal and it worked fine. After being home a day the computer crashed and stopped working altogether. Had an engineer look at it and it's been completely condemned! THe motherboard and Hardrive have burnt out. I was asked if I had had an electrical problem, ie was the house hit by a bolt of lightening? This may all be coincidental but was wondering if the inverter could have caused this? Once whilst the invertor was charging the red light on the invertor came on and stopped working. But I turned it of and back on then it worked fine again. Could this have been an over surge of electric? 

The inverter has charged the phones and new hair straighteners fine. Though it didn't work at all on my wife's previous hair straighteners. 

so the question is has anyone else experienced inverters blowing things up. is it possible that it was the inverter? Or am I being paranoid and the computer is faulty?


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## stevensir (Apr 6, 2009)

to clarify

I used a 500w (cheapish) I think (£50) Inverter from go outdoors to charge the computer battery. I used it whilst driving and when stopped. It was connected directly to the leisure battery.


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## clodhopper2006 (Aug 13, 2006)

No it's coincidental Stevensir. I cant think of any way you could have damaged your computer with an inverter. All the engineers at work use inverters to power there laptops with no ill effects. Dirt cheap 300w jobs too. Even if you got the polarity wrong it wouldn't harm you laptop. You'd kill your inverter but your laptop would be ok.
Motherboards and hard drives do fail!

bob


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## stevensir (Apr 6, 2009)

thanks Bob.

it is reasurring? any explanations why the computer's transformer hummed louder than when plugged into normal mains?


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## Patrick_Phillips (Aug 17, 2006)

clodhopper2006 said:


> No it's coincidental Stevensir. I cant think of any way you could have damaged your computer with an inverter. All the engineers at work use inverters to power there laptops with no ill effects. Dirt cheap 300w jobs too. Even if you got the polarity wrong it wouldn't harm you laptop. You'd kill your inverter but your laptop would be ok.
> Motherboards and hard drives do fail!
> bob


I agree with clodhopper but...
It is unusual for the motherboard and harddrive to both go at the same time...
I suspect it is the power supply.
Before you bin it, I'd get second opinion 8) 
Patrick


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## Pudsey_Bear (Sep 25, 2008)

Not likely, the charger box would stop anything nasty getting to the PC.

Kev.


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## stevensir (Apr 6, 2009)

thanks but still not sure why the transformer should buzz louder than when plugged in at home


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## Alemo (Mar 11, 2008)

I have the same problem with the laptop transformer making a noise when used on modified sine inverter. It makes no noise at home or when motorhome is on EHU.

Am concerned for inverter (1800w) or transformer (Sony).

Does anyone have any knowledge about this?

Laptop is Sony Vaio.

Alec


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## GerryD (Sep 20, 2007)

The transformer was buzzing because that is what they do. All transformers buzz to a certain extent. Your inverter would not produce AC mains voltage as clean as the power in your house so the transformer had to work harder and would therefore buzz louder.
As to what caused the motherboard and hard drive to go faulty, that is anybody's guess, but the most likely cause was a component failure somewhere that affected them both. Quite often with modern electronics the original fault is separate from the visible failure.
Important thing is that the computer failed safe and did not cause any problems externally.
Gerry


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## CliveMott (Mar 10, 2008)

Interesting one this.
I have used a modified sine wave (square wave with gaps) inverter to power my Laptop for years and recommended the same to a friend. He reported that as soon as he connected his laptop power supply to the inverter that the inverter stopped and the fault light came on. He brought round both his laptop and his converter.

I connected my laptop to his converter. Worked fine (Toshiba)
I connected his laptop to my spare converter. I grunted then the fault light came on.
I turned the inverter ON and OFF several times in quick succession and a small puff of smoke from the inverter indicated its demise. It went in the bin. I presume I was lucky I did not also wreck the laptop.

So, some laptops work off modified sine wave but not all. If you want to be sure then it has to be pure sine wave and deep pockets or the laptop manufacturers own set of 12 volt leads and power supply.

C.


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## Jean-Luc (Jul 21, 2005)

I don't know why people power low voltage DC equipment via an inverter, why expose the habitation battery to the unnecessary additional load used to invert up to mains AC voltage and then transform back to low voltage DC :? 
I choose DC to DC conversion when at all possible, for my laptop I use one of these and have no worries about the effect of modified sine wave power hitting my stuff.
BTW I also use it to power my 16V Philips LCD TV
Colin


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## GerryD (Sep 20, 2007)

Jean-Luc said:


> I don't know why people power low voltage DC equipment via an inverter, why expose the habitation battery to the unnecessary additional load used to invert up to mains AC voltage and then transform back to low voltage DC :?
> I choose DC to DC conversion when at all possible, for my laptop I use one of these and have no worries about the effect of modified sine wave power hitting my stuff.
> BTW I also use it to power my 16V Philips LCD TV
> Colin


Have to agree, always go DC to DC where possible even if stepping up. Clean power will always be better than the dirty electricity of an economy inverter. I only use an inverter where there is no alternative and I do not have the option of EHU.
Gerry


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## Pudsey_Bear (Sep 25, 2008)

I have to agree, but I should imagine it's partly cost, partly unsure of the technology, and partly having to have so many different 12v adaptors.

We run all ours of a small inverter, and not had any problems so far.

As a non techy type, may I propose a question in non techy type terms.

Assuming you have a fully charged 110ah battery.

You also have a 300watt inverter, you want to run a laptop, and a LCD TV.

Quite by chance you also have a 12v adaptor to run each item, which would run the battery down first, and how much faster.

IE both on inverter or both on 12v

Kev


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## Bagshanty (Jul 24, 2005)

Well I had always assumed the dc to dc converter is just an inverter with a different name. OK, no need to invert to 230V, but it must produce ac in order to transform the voltage to something higher than 12 V, then simply rectify and smooth the output at the required voltage.

I NEVER use my inverter with the engine running, because of the transient voltage spikes likely to be present. If one of these spikes (similar to a lightning strike on a 230V supply) arrived enough of it could get through to produce exactly the symptoms described.


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## stevensir (Apr 6, 2009)

Really interesting replies but now still not sure of the answer??? I like the idea of turing my 12v to 18v without inverting it to 230v. How do I do this? where can I get something that converts 12 dc to 18v dc so I can run it directly to my computer?


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## SpeedyDux (Jul 13, 2007)

Am I missing something here? I'm trying hard to remember some basic stuff about electricity. 

I'm assuming that the Maplin DC converter in Jean-Luc's link is basically a DC transformer and there is no AC conversion required at any stage in that device. I thought that the output voltage can be raised from 12 volts input in a DC to DC transformer (unless my brain is totally fried today) according to the coil ratios. 

If I am wrong I will go and stand in the corner with a pointy hat. :roll: 

SD


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## Pudsey_Bear (Sep 25, 2008)

I don't believe I just read that, wonders will never cease. :twisted: :roll: :wink: :lol: 8)


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## erneboy (Feb 8, 2007)

I got mine here,

https://www.laptopshop.co.uk/car-adapters.htm

Alan.


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## clodhopper2006 (Aug 13, 2006)

SpeedyDux said:


> Am I missing something here? I'm trying hard to remember some basic stuff about electricity.
> 
> I'm assuming that the Maplin DC converter in Jean-Luc's link is basically a DC transformer and there is no AC conversion required at any stage in that device. I thought that the output voltage can be raised from 12 volts input in a DC to DC transformer (unless my brain is totally fried today) according to the coil ratios.
> 
> ...


Get yer pointy hat out and stand in the corner forthwith :lol:

No such thing as a DC transformer as transformers work by creating a changing magnetic field across the windings. AC changes 50 times a second and this changing induces a voltage in the secondary proportionate to the number of turns in the windings.

DC to DC converters work in a variety of ways but I think the ones were taking about here work by temporarily storing the voltage and then releasing it to give a pulse affect which again by induction it is raised and smoothed at the new voltage.


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## Alemo (Mar 11, 2008)

Stevensir,

Maplin have three versions of a laptop power supply that runs off 12v

Each unit has a variety of plug versions to suit your laptop.

Walked into one of their shops today and found one on offer (was 39.99 selling for 29.99)

input voltage 12v - 16v
outputs selectable from 15v - 24v
120w

My laptop requires 19v so just the job.

Go on line and look for their nearest shop or order on line.

I hope this helps.

Alec


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## stevensir (Apr 6, 2009)

once again thank you for all the replies and wealth of in depth knowledge. The conclusion is 'use a 12v dc to 19v dc and the links provided seem a good purchase. Whether my inverter did any damage, seems unlikely, but I guess I'll never know for sure. N E way I'll await my replacement laptop and only use dc.


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## Jean-Luc (Jul 21, 2005)

Kev_n_Liz, in answer to your question about which is easier on your battery below is some findings which I posted a while ago when this issue was being discussed.

(all you old members, remember George Telford, I wonder where he is now !!!)

Following George Telfords dismissal of RoadDemon's (and myself's) questioning of his opinions I ran some tests today to get some facts regarding the relative power consumption of inverters and regulated d.c supply, for power for electronic equipment, here are my findings.

Appliance being tested : Mitsubishi Black Diamond 15 inch LCD (Maximum power consumption 30 watts) supplied ex factory with an external transformer supplying 12 volt dc from mains supply.

1.Using 250 watt modified sine wave invertor and mains transformer
Current draw from battery - no load = 0.67 ah - powering tv = 3.81 ah

2.Using 150 watt pure sine wave inverter and mains transformer
Current draw from battery - no load = 1.56 ah - powering tv = 4.98 ah

3.Using Amperor regulated 12 volt supply
Current draw from battery - no load = 0.00 ah - powering tv = 2.80 ah

Conclusion (for me)
Staying with dc current is best, Mod. sine wave is second best and leave the pure sine wave switched off unless absolutely necessary for sensitive equipment.
Someone else can do the relative percentage efficiencies but staying dc seems to use at least 30% less battery than inverting.

About how a DC to DC works, think of a mobile phone car charger, this is a DC to DC charger in common use, there is no 'pulsing' or any other kind of 'alternating' characteristics (AC) to the power they deliver, it is smooth direct current (DC) just like what comes out of a battery. 
Those used to power TV's Laptops etc are similar only built to deliver higher currents, some also have the facility to select the voltage output from a variety of options, usually between 12V and 24V. The main benifit is that they produce a stable DC voltage and will not subject the item they are powering to variations in voltage.


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## CliveMott (Mar 10, 2008)

The small Laptop DC-DC power supplies are inverter-rectifier-regulators. If one of these is sufficient for your needs then its probably the best solution. But if you have various bits of mains kit you want to run and your van has a built in inverter that feeds the sockets then you need to put a price on convienience. 

Horses for courses - and are you really that tight on battery power?

C.


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## clodhopper2006 (Aug 13, 2006)

Jean-Luc said:


> About how a DC to DC works, think of a mobile phone car charger, this is a DC to DC charger in common use, there is no 'pulsing' or any other kind of 'alternating' characteristics (AC) to the power they deliver, it is smooth direct current (DC) just like what comes out of a battery.
> Those used to power TV's Laptops etc are similar only built to deliver higher currents, some also have the facility to select the voltage output from a variety of options, usually between 12V and 24V. The main benifit is that they produce a stable DC voltage and will not subject the item they are powering to variations in voltage.


I think you'll find we're talking electronic switch-mode DC - DC converters here. This uses a method known as pulse width modulation from which it;s output is filtered and regulated. If you put a scope on it you'd find the output like a saw edge not particularly smooth.


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## Jean-Luc (Jul 21, 2005)

Clive and clodhopper2006, you guys seem to be qualified professionals in the filed of electronics, which I am not. 
My question to you is, are there differences in the characteristics of the DC power output when an external power supply unit connected to,
a) a true (pure) sine wave inverter, 
b) a quasi (modified) sine wave inverter, 
c) a DC supply
If there is, which one is the same as, or is closest to, that which is delivered when the power supply unit is connected to the domestic grid.

Colin


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## clodhopper2006 (Aug 13, 2006)

Jean-Luc said:


> Clive and clodhopper2006, you guys seem to be qualified professionals in the filed of electronics, which I am not.
> My question to you is, are there differences in the characteristics of the DC power output when an external power supply unit connected to,
> a) a true (pure) sine wave inverter,
> b) a quasi (modified) sine wave inverter,
> ...


I'm a bit confused now Colin, we were talking about DC DC converters and now inverters. The output from an inverter is AC not DC so clearly C is completely diferent to the national grid. Can you run your question past me again rephrased a little?

thanks,

Bob


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## Jean-Luc (Jul 21, 2005)

Sorry to confuse Bob.
I know the OP was about an inverter, however as you guys seem to be qualified experts I was just trying to solicit your opinions as to which option for the supply (input) side if a PSU (transformer) ultimately best matches that which is delivered when using a national grid mains connection. Opinions expressed seem to indicate if using technical measuring equipment differences can be seen, are these significant to the long-term health of the lappies, tv's camcorders, chargers and other equipment designed to operate on a low voltage DC supply.
Option C would be a different piece of kit as it would have a DC input (cigar lighter socket connection) as opposed to options A & B which would have an AC input (mains socket connection). All ultimately supplying a low voltage DC current.

Colin


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## clodhopper2006 (Aug 13, 2006)

Yes as you say there are differences between inverter outputs and non will give as pure a sinewave as mains supply. In the same way if you raise a DC voltage to a higher one it will never be a true DC in the sense of a battery.
In all honesty I cant tell you which is going to be kinder your laptop as it's not my area. I don't really think anyone else could say for sure either except the laptop manufacturers who will know the tollerences of their equipment.
That said and going back to the OP I think it's highly unlikely that the inverter killed the laptop.


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