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Dev7 Newbie Joined: 15/10/2025 Location: South AfricaPosts: 1
Posted: 01:01pm 15 Oct 2025
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Hi all, I am designing a sine wave inverter using a full bridge, low frequency transformer (E-core) topology. I am using 20kHz SPWM generated by an Arduino Nano.
I have seen many low power inverter schematics such as the one on the EG8010 datasheet directly connecting a 2.2uF capacitor across the secondary of the transformer and using the leakage inductance of the primary to filter out the 20kHz SPWM. However, from what I have read on this forum, it seems a correctly sized choke is needed between the H-bridge and the low frequency transformer?
I am struggling to correctly design the stage after the H-bridge. What would be a suitable inductance for a choke on the primary of the transformer and is a 1uF or 2.2uF capacitor better suited for the transformer secondary?
Specs: Input - 12V DC Output - 230V, 50Hz Power - 230VA
Schematic is attached. I can also upload my code if needed. Please let me know if you see any obvious flaws in my design.
analog8484 Senior Member Joined: 11/11/2021 Location: United StatesPosts: 166
Posted: 04:44pm 16 Oct 2025
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For that low power level the leakage inductance may be enough.