Inverters

Scotty

I run a Pure Sinewave 150 watt inverter to charge batteries and run my night light.

I run my laptop off a Kerio DC charger through the cig lighter socket.

Cheers

A pure sinewave inverter is worth getting if you're not going to get a Kerio as Willem has. Modified sine wave inverters tend to stuff batteries after a while, and laptop batteries aren't real cheap. I'm sure that someone has a technical explanation as to why the pure sinewave inverters are best.

Andrew

Scotty,
I was told that the Pure Sine Inverters have a Cleaner Current as apposed to Modified Sine that’s why I picked up a 600W Pure Sine Inverter from DSE from Memory for $189.00! I think? I run the Xbox and a 15' LCD Screen of it no worries plus it charges the Lappy, iPod and Camera Batteries….ect

Matt

we use 150w sine wave inverters in our reps cars to charge the laptops for $200
have one in the caravan to charge the laptop and other batteries. In summer we use a 240v fan as no noise more air and less power cheaper than 12v fan
http://members.dodo.net.au/~landline/inverters.htm

I've had 2 digitor 300w burn out in last 12 months so changed brands. Mine is mounted to the cargo barrier by flat OKI straps.

Ah, Inverters.
Modified sine wave == square wave with the sharp corners removed.
Good for equipment that have switch mode power supplies in them.
ie TV, videos, some laptop power supplies.

Pure sine wave == 240V AC supply.
good for any equipment.
esp fridges, and other equipment that need a real power supply. ie not switch mode.

simple explanation:
power dissipated = voltage X current.
for "modified" the switching transistors are either fully on or off.
ie
On 0V * 10A = 0 watts
Off 240V * 0A = 0 watts
minimal power dissipation in transistors. rating is in transformer
Modified is more efficient but has limited uses depending on equipment.

for pure sine wave the transistors are transient
ie in middle of cycle 120v * 10A = 1200 Watts
so power during one cycle of 240v changes from 0 watts to 1200 watts and back to 0 watts.
Therefore pure produces less output for size and has less efficiency (some power is dissipated in the switching transistors) but will power any 240V ac device.

ps. is there some way one can upload graphic details for things like this for all to view? A section of the site for people to find answers instead of asking the same questions over and over again? A way of helping people to understand what is actually happening and helping members for future problems?
Techie

Sorry, I should qualify my "stuff batteries" statement. Running a laptop from a "non pure sinewave" inverter using the normal 240v adapter seems to stuff batteries, in my limited experience. I don't know if this is any different to using a battery charger for, say, video camera batteries the same way. I've used mine for video and digital camera batteries with no trouble, but I suppose it's a bit different to using a laptop from in inverter. Ultimately, if you use a laptop from AC power all the time, after a while the battery will cease to work. I suppose that's why laptop manuals usually recommend cycling the battery by using it on battery from time to time. I'm still not sure about the difference between pure sinewave inverters and laptop batteries,

Andrew

I certianly don't have the technical guru advice mentioned above, but I have very dsimple 80W Inverter I purchased from Dick Smith for about $80. I have it mounted under the passengers seat and I modified it so rather than havng to plug into it under there.. there is a switch on the center console and a power point next to the gear stick. I runa ;laptp off it just fine (when running off 240V Laptops should always have the batteries removed otherwise you are overhcarging them) (oncve they are fully charged of course) I also charge mobiule phoe and run battery charger for the torch AA and D cells..
All I can say is it all works beautifully for 12 months now. Have just moved to new Nissan and wil lbe reinstalling the same set up...

I knew I saw it somewhere. Try this: (hope it works)

link text

Any one run an Engles fridge off the inverter and for how long?

Thanks for all the advice guys.
I ended up going with a 300W (1000W surge) mod sine wave inverter from Jaycar for $99.
I consulted with my father, who is a former electrician and a whiz on all things electrical.
Hope this also helps others!
Cheers,
Scotty

Page 233 of the DSE 04/05 catalog has a bit of a blurb on inverters, efficiency and power usage etc. THey also mention about the potential for "actually destroy the laptop battery packs". So it seems that intermittent usage on a normal inverter won't hurt the laptop battery, but they are not real clear about how long they can be used without damage. I've seen one stuffed, so with batteries being between $100 and $300, it's sort of line ball between a normal inverter and a sine wave inverter.

Whats the saying, "Caveat Emptor"

Andrew

Volante -
sign up for electrical engineering - I am one.
Have been doing this since mid 70's.
I only give the knowlege I have - Not tear down someone elses.
Techie.