laptop voltage question

TomTomTom

TomTomTom

TomTomTom

Associate
Joined
6 Feb 2004
Posts
812
Hi,
I want to use a car adapter to power me laptop.

The car adapters I've seen have various output voltage settings, 20 volts DC being one of the settings. The standard power supply for my lappy however has an output of 19 VDC. None of the car adapters have 19 VDC specifically.

Would the laptop get damaged by just 1 volt more than it's rated to need (20 VDC)?

The reason I thought it might be possible is I used to have a GPS that could take anywhere from 6 VDC to 12 VDC.

Anyone out there with a more specific knowledge of electronics who could answer that definatively (or someone who's ever put a slight over-volt into a lappy before)?

(don't really want to use an inverter)

Thanks
 
Frank_Rizzo said:
Not worth the risk.

What you could do is get a 12v to 240v invertor and just plug your laptop psu into that.
Click to expand...
Oh ok. Bummer. My only concern with inverters is how hot they get and that they therefore also put a bit of excessive load on the bat.

However, I wouldn't exactly be screaming "Nooooo!" if this particular lappy kicked it; although it would be a bit dissappointing. Any ideas on the likelyhood of it getting fried?

Another reason I thought it could work is looking at Motherboard moniter and how none of the voltages are so exact.... hmmm.
 
If you don't mind the risk of frying it give it a go. Just beware that it could cause a fire so never leave it unattended.

+1v on the input should be fine as the laptop should regulate the voltage to 19v. What you need to check also is:

a) How stable is the adapter?
Some adapters may have poor regulation and thus vary the voltage depending on the load. What if you rev the engine etc? It will depend on the quality of the adapter.

b) Can the adapter provide sufficient amps? Check the DC amps or power rating of the laptop psu block and ensure the adapter is sufficient.

As I say, you can try it, just be aware that fires can start easily if wrong voltages are applied to a device, or if inferior devices are used as power sources. You may not mind the laptop going up in a puff of smoke but what about the car?
 
Thanks. That's good information. I'll take all that into account including the precautions. I'll bring the standard PSU with me next time to the car adapter store and compare the specs. If I do try it, I'll report back on whether the lappy is humming or sizzling (I'll be careful though and not let it get as far as sizzle).

EDIT: Just occured to me from what you said, that it could appear to work, but because of the +1VDC have a tendency for overheating, so I'll be extra careful if I try it.
 
Last edited:
lol, should've worked though. I once had to rig a laptop up to a power supply that varied from 2 to 50v DC and actually had to give it 24v (19v laptop) cause it was taking so much juice the output needle was dropping as it could'nt cope with the amperage draw, laptop worked fine once it got the right psu though, strongly doubt 1v would cause any grief. Would use a proper laptop supply though as run of the mill converters would'nt be as tight with regulation etc.. as a proper laptop psu.
 
You must log in or register to reply here.
Back
Top Bottom