Inverter/ Charger Question

[d2dave]

I have a cheap 150 watt invertor which has a crook fan so I am looking for a new one. Now one of my uses will be for charging/running laptop.

A friend of mine has used the 150 watt to run his laptop without any trouble.

However I decided to check the specs on mine and for input it says,

"100-220 volts ac 1.5 A"

My question is. If this is using 1.5 amps this would mean that it would be using 360 watts.
I can't believe that this small charger would be using this much power and if it was I would need at least a 400 watt inverter.

Am I missing something here?

[bee utey]

Switch mode power supplies like that with a wide range of input voltages will list the maximum current at the lowest voltage needed to create the output power. So at 220V in it would need less than 1/2 the maximum current specified, ie around 0.5 amps.

[Homestar]

Dave, I would recommend a 300 watt unit for charging a laptop. If you have a need to use it for anything else, then go bigger again. I just bought a Kogan 1000 watt pure sine wave inverter for $129. Works great, but not sure what life expectancy I'll get from it yet...:angel:

[iPom]

As Bacicat as said, I'd be going for at least a 300W inverter - if that suits your particular laptops power needs.

A lot of inverters are listed has having "X" amount of watts, however that may well be the max surge current of the unit - you really don't want to be running it at a max surge current, what you are looking for is the continuous current.

To be on the safe side I would be looking for an inverter with a continuous current of 25% more that what you require to be on the safe side.

[d2dave]

I am looking at a 300 watt with a 600 surge capacity. I had no doubt that 300 would do but I just did not understand how my small charger could be pulling 360 watts.

Bee utey has answered that for me.

I am looking at one of these.

SureSine ? Morningstar Corporation (http://www.morningstarcorp.com/products/suresine/)

I am waiting for a nephew living in the US to get back to me on postage.

[Homestar]

That looks like a nice unit Dave. :)

[bee utey]

That looks like a nice unit Dave. :)
But it's 110V output, so useless for anything other than some switchmode equipment.

[Tombie]

Some gear is very sensitive to modified sinewave so look for a pure sinewave.

For running a laptop, id suggest going the more efficient Dc-Dc converter route...

[d2dave]

But it's 110V output, so useless for anything other than some switchmode equipment.

Go back and have another look. It is available in both Au and US voltages.

[d2dave]

That looks like a nice unit Dave. :)

It is a bit pricy but I think it is worth it. It has no fan so has the lowest no load consumption that I have seen.

The main feature I like is that when the load falls below 8 watts it goes to sleep and draws little current.

When camped up the river in my caravan I can have it plugged in indefinitely.

[Homestar]

Yeah, I had a look at the specs and I like that feature. I bought a cheap one as it's all I can afford at the moment. I'll be mounting mine so I can get to the main switch easily to turn it off when not required. Let us know how it goes as I will be in the market for a good one at some stage.

[d2dave]

After a lot of searching I found a reasonably priced unit that also had reasonable postage, so I ordered it.

[Blknight.aus]

if its just the fan why not just replace it, the fans are usualy only 12V cpu
fans

[d2dave]

I have always wanted a pure sin wave and as I said earlier I also wanted one that goes to sleep, so it can be left on continuously.

[Red90]

If just for a laptop you do not need an inverter. Laptops run on DC. You just need a simple car adapter for the laptop power.

[d2dave]

I also want to run caravan lights.

[p38arover]

If just for a laptop you do not need an inverter. Laptops run on DC. You just need a simple car adapter for the laptop power.

My laptop requires 19 volts. The car adapters must step up the voltage using an internal inverter.

[d2dave]

Mine is also 19 volts.

[dickyjoe]

I'd just buy a power park for your laptop that steps 12 volt DC to the required voltage for your laptop. Jaycar sell these..

[Red90]

My laptop requires 19 volts. The car adapters must step up the voltage using an internal inverter.


The are just simple dc voltage converters. Much cheaper than an inverter. Most laptops use 19 volts.

[dickyjoe]

Something like one of these jiggers would do the trick. http://m.jaycar.com.au/m_productView.asp?ID=MP3472

[d2dave]

Something like one of these jiggers would do the trick. 150W Car Laptop Power Supply- Jaycar Electronics (http://m.jaycar.com.au/m_productView.asp?ID=MP3472)

You can buy an inverter for half that.

[dickyjoe]

Keep us informed on what you choose and buy.

[d2dave]

Keep us informed on what you choose and buy.

Read post number 12

[dickyjoe]

Well done!

[Bushie]

Something like one of these jiggers would do the trick. 150W Car Laptop Power Supply- Jaycar Electronics (http://m.jaycar.com.au/m_productView.asp?ID=MP3472)

I've been using one of them for years for my small laptop, hasn't missed a beat.


Martyn