This instructable is a guide for repairing/increasing the output power of a simple dc-AC power converter (this instructable address the boost dc-dc converter based power inverter). For the record, a power inverter converts ~ 12V dc--> ~120 AC
(normally non-sinusoidal). to increase the power output, the amount of output current the device can source is increased, whereas its output voltage remains the same.
Below is an MS Paint rendition of the first stage of a boot dc-dc. the boost stage amplifies the current from a lower voltage to a higher voltage, all in a DC environment. Read about dc-dc inverters on wikipedia.dc-dc converter (boost)
The boost topology can be made smaller and lighter than huge transformer systems, like an APC or UPS power supply.
At the heart of this system is two N channel MOSFETS. (your inverters configuration could have anywhere from 1 to 4 based upon design)
For those who dont know what a mosfet is, its simple enough to say its a kinda like
a really fast switch.
The characteristics of this switch
are what determines how much current the dc side of the device can source.