A consumable chip comprising a variable threshold feedback circuit and a storage unit, wherein the variable threshold feedback circuit comprises: a control unit, and a feedback module, comprising four different feedback units (a, b, c, d) that are connected between an output terminal and ground in parallel, wherein each one of the feedback units (a, b, c, d) comprises a gating component and a feedback component that are connected in series between the output terminal and the ground; wherein the control unit is electrically connected with the gating component of each one of the feedback units (a, b, c, d) such that the feedback module selects and outputs an electrical signal of one of the feedback units (a, b, c, d) to the output terminal; wherein the control input terminal of the control unit is electrically connected to the storage unit of the consumable, and the feedback module is switched among the four feedback units (a, b, c, d) through a switch under the control of the storage unit,wherein the feedback component of a first feedback unit (a) is a first feedback transistor, and when the first feedback unit (a) is selected, the voltage of a drain of the first feedback transistor is output; wherein the feedback component of a second feedback unit (b) is a second feedback transistor, and when the second feedback unit (b) is selected, the voltage of a drain of the second feedback transistor is output; characterized in that the feedback component of a third feedback unit (c) is comprised of a third feedback transistor and a DC power supply that are connected in series, and when the third feedback unit (c) is selected, the sum of the voltage of a drain of the third feedback transistor and the voltage of the DC power supply is output; the feedback component of a fourth feedback unit (d) is a fourth feedback transistor, and a gate of the fourth feedback transistor is grounded such that the current in the fourth feedback unit is 0 when the fourth feedback unit (d) is selected; and the width-to-length ratio of the first feedback transistor is different from that of the second feedback transistor. a control unit, and a feedback module, comprising four different feedback units (a, b, c, d) that are connected between an output terminal and ground in parallel, wherein each one of the feedback units (a, b, c, d) comprises a gating component and a feedback component that are connected in series between the output terminal and the ground; wherein the control unit is electrically connected with the gating component of each one of the feedback units (a, b, c, d) such that the feedback module selects and outputs an electrical signal of one of the feedback units (a, b, c, d) to the output terminal; wherein the control input terminal of the control unit is electrically connected to the storage unit of the consumable, and the feedback module is switched among the four feedback units (a, b, c, d) through a switch under the control of the storage unit,wherein the feedback component of a first feedback unit (a) is a first feedback transistor, and when the first feedback unit (a) is selected, the voltage of a drain of the first feedback transistor is output; wherein the feedback component of a second feedback unit (b) is a second feedback transistor, and when the second feedback unit (b) is selected, the voltage of a drain of the second feedback transistor is output; characterized in that the feedback component of a third feedback unit (c) is comprised of a third feedback transistor and a DC power supply that are connected in series, and when the third feedback unit (c) is selected, the sum of the voltage of a drain of the third feedback transistor and the voltage of the DC power supply is output; the feedback component of a fourth feedback unit (d) is a fourth feedback transistor, and a gate of the fourth feedback transistor is grounded such that the current in the fourth feedback unit is 0 when the fourth feedback unit (d) is selected; and the width-to-length ratio of the first feedback transistor is different from that of the second feedback transistor.