Low-cost high-precision AC sensor circuit and detection system

Abstract

The utility model relates to a low-cost high-precision alternating current sensor circuit and a detection system. The low-cost high-precision alternating current sensor circuit comprises a mutual inductor and an operational amplifier, a coil on one side of the mutual inductor is connected with AC input, and a coil on the other side is connected with a first resistor. The negative input end of the operational amplifier is electrically connected with a second resistor, and the other end of the second resistor is grounded; the positive input end of the operational amplifier is electrically connected with a third resistor; the positive input end of the operational amplifier is electrically connected with a fourth resistor, and the other end of the fourth resistor is connected with the power input end. The negative input end and the output end of the operational amplifier are electrically connected through a fifth resistor; according to a potential difference formed between two power supplies, two resistors are connected in series between the two power supplies, an intermediate voltage is obtained according to requirements, then the intermediate voltage is amplified through a proportional amplifier, the voltage is amplified while bias is achieved, bias and amplification of an alternating current signal generated by a mutual inductor are achieved at the same time through only one operational amplifier, and the output voltage of the mutual inductor is increased. Therefore, the product is low in cost and high in precision at the same time.

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