Current sampling circuit

A current sampling circuit, comprising:

• a sampling unit, wherein the sampling unit is provided with at least two sampling input terminals, a sampling reference terminal, and at least one sampling output terminal;
• wherein the current sampling circuit is electrically connected with a power conversion device for detecting a working current;
• the power conversion device is provided with a first voltage terminal and a second voltage terminal;
• the power conversion device comprises at least one switching circuit and at least one winding group;
• each of the at least one winding group comprises two windings;
• the winding is provided with a first end and a second end;
• the second ends of the windings in one winding group are electrically connected with each other and with the first voltage terminal;
• the first ends of the windings in one winding group are electrically connected with the at least one switching circuit;
• a voltage waveform is provided across each winding changing according to a working frequency in operation;
• in each of the at least one winding group, the voltage waveforms corresponding to the two windings are in a phase offset of 180 degrees;
• wherein the sampling reference terminal is directly connected to the first voltage terminal, and the at least two sampling input terminals are respectively directly connected to the first ends of the corresponding windings in a winding group or winding groups;
• and
• wherein the sampling unit is configured to sample voltage waveforms across the windings, averaging by superposing the voltage waveforms to obtain a first output signal, and outputting the first output signal through the at least one sampling output terminal;
• the first output signal is proportional to the working current of the power conversion device.