inverters

[Guest]

Where can I buy an inverter suitable for running a laptop on board without paying marine "premiums" I cannot find any on the RS site?

Also thoughts on PC chart software choice would be appreciated.



brian mackenzie

 

[davel]

You have a couple of approaches.
1. Buy a DC to AC inverter - widely available - check out the stores in the YBW shopping mall or other on-line chandlers. Maplin also have a low cost version. Advantages are, low cost (for a low power device), can be used to power a variety of mains driven low power appliances (small TV, Phone charger etc). Disadvantages are size (relatively large) and power drain on batteries (your effectively doing a double power conversion - 12v DC to 230v AC to "x" volts DC - and each conversion is inefficient, hence excess battery drain).
2. Buy a DC to DC power convertor. Targus do a product that's specifically designed to convert 12 volts to a range of voltages demanded by various laptops (you buy a cheap plug to adapt to the particular laptop you're using). Advantages - more efficient so less power drain, smaller size. Disadvantages - relatively expensive (circa £80) and not as versatile (can only use for PC power). As a variation on this approach - if your confident with electronics, I could provide you with a circuit diagram so you could build your own version at a cost of a few pounds.

I guess a final alternative would be to try and find a laptop that can be driven by 12 volts directly - they may exist.

Hope this helps

Dave L.
Location: 50 51.0 N 1 18.6 W

 

[billskip]

Maplins do a 300w(600wsurge) for £49.99 see www.maplin.co.uk and type inverters in the search..or you can check on www.ebay.co.uk..they also sell them but not much cheaper at moment..at least with maplin you can get some sort of gtee.

Bill
www.aegeansailing.co.uk

www.macsyachting.com

 

[alastair]

The Dc to DC converter seems a good idea. Id be keen to build one! Grateful if you could supply me with the details.

Regards
Alastair

 

[ean_p]

Re: Voltage supply

Could you send me a copy of the circuit diagram please Dave.....iananji@hotmail.com

ta
Ian P.

 

[Buck]

I have one of the £50 jobs from Maplin although when I bought it it was only £40 so you can guess I've had it a while, I use it a lot for the lap top, the lap top supply is very voltage tollerant i.e. it accepts power levels from 100 to 270 volts 40 to 70 hz and it always runs great.

Buck

The thing about men and fish is one is always trying to eat the other.

 

[AndrewB]

Small warning

I've used inverters for about 5 years. A lesson - they don't seem to deliver sustained power at the maximum for which they are rated, so you should specify an oversized inverter. PC power transfomers need more power than they used to. My latest requires 1.1 amps, and my £120 Maplin's "Handy Mains" inverter (product code CC86T), though rated at 1.1 amps simply cuts out.

I prefer DC-DC converters, they seem more reliable and hit the battery less hard. Your PC manufacturers will probably be able to supply one in place of the usual transformer. (Don't make the mistake of confusing these converters with transformers though, as I did some years ago!)

 

[billskip]

Re: Small warning

Re AndrewB..maybe you can explain why £120 for a 200w (500W) is better than £50 for a 300w (600w)..before I go and buy one next week..many thanks

Bill
www.aegeansailing.co.uk

www.macsyachting.com

 

[davel]

Send me a PM with your e-mail address and I'll send you a copy

Dave L.
Location: 50 51.0 N 1 18.6 W

 

[Bluefin]

Hi

I have just bought a 12V to 230V converter, but have not used it yet. It's output is only 150W, but the supplier said it should be more than enough for a laptop, I hope so!

Do I need to earth it too? If so where to?

Re chart software I would suggest Oziexplorer. It is easy to use and not so expensive to register. You can download a trial version from theie website.


Thanks

Ed

 

[davel]

Should be fine. Check the power requirement on your laptop power supply for confirmation (there'll be a labelon it giving this info). My Toshiba PSU is rated at 240 volts, 0.55 amps which equates to 240 x 0.55 =132 watts.
All equipment should be Double insulated so no earth requirement.

Agree with recommendation of OziExplorer - I use it as well.

Dave L.
Location: 50 51.0 N 1 18.6 W

 

[pauln]

I'd be grateful for cct diagram as well.

pnewton@tesco.net

Thanks

 

[Guest]

Most reletavily modern Laptops have a 12v power option from the manufacturer. Trouble is the lead costs £50+. You can get one made up at an electronics shop for about £20.

 

[Buck]

Re: Small warning

1.1 amps, what the hell is it? A valve running Kray mainframe? My laptop psu draws 0.4 to 0.5 amps at 230v.

Buck

The thing about men and fish is one is always trying to eat the other.

 

[AndrewB]

Re: Small warning

Its the s***ing transformer that's power hungry, not the PC!

I guess some marketting genius thought that if the PC bombed, the transformers could be used as heat units in an electronic pop-up toaster.

(Its a DELL Latitude C400).

 

[rogerm]

For non marine invertors ie 12v -> 240vac (or convertors 12v -> 15 or so vdc) try looking at www.cpc.co.uk. They are distributers like RS/Farnell but cater more for the entertainment industry rather than industrial. They are quite happy to deal with indivuals waving credit cards. They have at least 6-8 in their catalogue. I can't really remember the prices off the top of my head but think of about £50 up +VAT. I think the smallest is about 150W and they go up to at least 600W. BUT don't go buying a MUCH bigger inverter than your needs. Inverters tend to draw quite a bit even if nothing is plugged in. The bigger the inverter the bigger the draw. So buy one the size you need + say 25-30%. Laptops are not that bad in the power-on surge area but if you want to use it for other things as well then you need to check that the inverter will handle it.
As someone else said the most 'efficient' way is to get the 12v convertor (ie car adaptor) that is specified for your laptop (and this is usually more than just a lead! If it is really just a lead then it runs on 12v anyway....).
The most universal is the inverter (but watch the current draw).
Roger

 

[billskip]

just been to maplins and asked why they said on the net 300w cont 600 w surge when on the box it says 300w contin 310w surge they sadi its mistake..bought one and then read instructions which said max cont use 150 w went back and they said take no notice its ok for 300 w !!

Bill
www.aegeansailing.co.uk

www.macsyachting.com