Power Inverters ???

[billt]

I'm ignorant when it comes to electricity. Can someone explain in English what a power invertor does? It looks like you're getting something for nothing. Low power in, but lots of voltage and wattage out. They seem handy enough. Could you use one to boost power with a generator? Thanks in advance.

http://www.harborfreight.com/2000-Watt-Continuous4000-Watt-Peak-Power-Inverter-69662.html?ccdenc=eyJjb2RlIjoiNjQ3MTAyMTciLCJza3UiOiI2OTY2MiIsImlzIjoiMTI5Ljk5IiwicHJvZHVjdF9p%0D%0AZCI6Ijg5MzAifQ%3D%3D%0D%0A&utm_medium=email&utm_campaign=4013a&utm_source=1010

[TAB]

BAsicly a power inverter take a low voltage direct current( tipically 12 or 24 volt)  and turns it in to 110v  alternating current.(generally speaking)    Dumbed down, it means you can take a car battery and "plug" something  into it.   there are bunch of goods and bads to go along with that, but thats it in a nut shell.   PS, get the best you can aford, hf stuff is junk.

[Frosty]

As TAB said - PS, get the best you can aford, hf stuff is junk! It's cheap a$$ crap from china, Korea etc.

[Solus]

What they give up for voltage is AMPS.  Probably can't run a heater off of it.

Also, they should be sized to your vehicles battery/charging system  capacity.  It is possible to hook up an inverter that can draw power from the battery faster than the charging system can replace it.

That one looks pretty big...likely aimed at a dual battery heavy duty charging system in a big RV.

Another thing it will drain a battery if left attached with noting drawing power if the vehicle is turned off...guess how I know that.

Perhaps they have models that will shut down the battery side if there is no load on the output side...if not disconnect it from the battery as soon as possible when the engine is not running.

[billt]

Could you attach one to the 12 volt receptacle on a generator?

[Sponsor]

[TAB]

you could. But it would be better to plug it into the generator itself.   inverts use alot of power( nothing is free)  there would be a loss of power.  Think of it like opening up a 357 mag shell, using the powder and the bullet for a light 38 load and throwing the rest away.

[Rastus]

P = E x I, or...watts = voltage * amperage

So....13.8 volts time 10 amps is 138 watts of power.

Accordingly, 120 volts (typical AC) times 10 amps is 1,200 watts of power.

So..if you want to know amps requirement, then I = P/E

Which says the amps drawn are equal to the watts divided by voltage.

So if you have a 2000 watt heater in the house on 120 volts, its 2000 watts divided by 120 volts for an amperage reading of 16.7 anps.    Use the same logic for your car or DC current.

[TAB]

Um power is rarly 120 volts.   tipically its 115-118.    if you are far away from the transformer, its even lower.  Its a range where 120 is the highest and 110 is the lowest. 

[billt]

Thanks guys.

[les snyder]

if you plan on running any electronics, you should invest in a pure sine wave inverter.... there is a lot of good information on "ar15.com"... I found this to be a very informative thread, although I have pretty much converted to 12v for hurricane backup... my setup is based on a deep discharge trolling motor, and a 12v female power tap, with inline fuse

http://www.ar15.com/forums/t_10_17/632626_Build_your_own_portable_power_station__An_ARFcom_tutorial__very_pic_heavy_.html

protective cap on the positive terminal has been removed for the pic