Power Inverter Without a Transformer? Please Help

[Hardergamer7]

Hi, I'm new here and looking at this True Sine Wave Power Inverter from AliExpress, but I have never seen any inverter without a transformer?
How do they work without one, and how does this one's build look for a cheapish China one? (£125)
As I'm not abele to spend much money as it's to power a 75w 240v fridge with a 900w start up load (30 seconds), a small 600w kettle and a microwave oven with a 1400w peak load, the kettle and oven won't be run at the same time, and the power for the inverter is coming from a 400w panel and 300ah of Lb batteries all in a garden shed on an allotment.

Also, I just had to return another inverter I got off ebay that was claiming to be a true sine wave, but I soon found out it was a modified wave which made the fridge loud as hell.

So please feel free to tell me what you think.

Aaron.

 

[Lucien Nunes]

The transformer is the toroid labelled 'amorphous inverter.' The heavy leads in glassfibre braid form the primary and the enamelled copper wire the secondary. It runs at such a high frequency that very few turns are needed and the core area is very small.

I think the rating is probably a little optimistic, it's quite lightly built, but impossible to tell with any certainly how it will last or perform. The devil is in the detail - e.g. capacitor ESR and lifetime, transistor rating, design of the bridge driver - which can only be guessed at without measurement and testing. I can see things I would design differently.