1Josehf Murchison 9 years ago Unless you just want to prove you can do it, it is easier and cheaper to buy than it is to build. If you build a 5000 watt inverter with new transistors or mosfetts, the transistors can cost over $500, and that is without the cost of heat sinks, resistors, capacitors and more. A 5000 watt modified sine wave inverter can cost as little as $400. I bought 13, 2000-watt inverter boards without the signal generator or control circuits for $10. I disassembled one board to reverse engineered it, to see how it worked. Now I can build a 26,000-watt power supply for less than $100. I can give you diagrams to build an inverter if you like from a modified sine wave signal generator to mosfett or transistor inverter circuits. If you like just privet message me.