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3-phase voltage monitor, phase reversal

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New Member
I got the scheme from a 380VAC voltage monitor, where the device has the ability to detect phase reversals and detect voltage levels.
I have tried simulating in LTSPieceXVII and giving a 1.7V DC voltage to the output.
But I don't know how this circuit works and the formula is mainly on R1, R2 and C1.
Please help me about the workings of the circuit and formulas, so that I can determine the exact component value so that I can design the output of the tool that is in accordance with the ADC level (+ 5V).
I really appreciate every assistance given
thank you



Well-Known Member
Most Helpful Member
I believe you are looking at Phase Sequence or Phase Rotation where a phase reversal is indicated. Circuits which do this are more about line frequency than voltage. You may want to give this a read and look at their illustrated figures. The formulas are in the link While the link addresses 60 Hz making the circuit for 50 Hz would be a matter of changing several resistances. The linked circuits use LEDs which can be replaced with opto-couplers to give you logic states for normal or a reversed phase.

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