Phase-sensitive detection circuit

Abstract

The invention discloses a phase-sensitive detection circuit, which comprises a comparator IC1A, a comparator IC1B, a non-inverting amplifier IC2, an inverting amplifier IC3, a resistor R8, a resistor R14 and a capacitor E1, wherein the non-inverting end of the comparator IC1A is used for receiving an excitation sine wave signal; the output end of the comparator IC1A is connected with the inhibiting end of the inverting amplifier IC3; the inverting end of the comparator IC1B is used for receiving an excitation sine wave signal; the output end of the comparator IC1B is connected with the inhibiting end of the non-inverting amplifier IC2; the non-inverting input end of the non-inverting amplifier IC2 is used for receiving an output signal of a differential transformer; the inverting input end of the non-inverting amplifier IC2 is grounded, and is connected with the output end of the non-inverting amplifier IC2 through a resistor R7; the non-inverting and inverting input ends of the inverting amplifier IC3 are used for receiving an output signal of the differential transformer; the non-inverting input end of the inverting amplifier IC3 is grounded through a resistor R11; the inverting input end of the inverting amplifier IC3 is connected with the output end of the inverting amplifier IC3 through a resistor R13; the output end of the non-inverting amplifier IC2 is connected with the output end of the inverting amplifier IC3 through the resistor R8 and the resistor R14 which are connected in series; and one end of the capacitor E1 is connected with the connected end of the resistor R8 and the resistor R14, and the other end of the capacitor E1 is grounded.

Description

technical field [0001] The invention relates to a phase sensitive detection circuit. Background technique [0002] Differential transformer (LVDT) is a transformer device widely used in electronic technology and non-electricity detection to measure displacement, pressure, vibration and other non-electrical parameters. It can be used for both static and dynamic measurements. Phase-sensitive detection circuits are usually used when processing LVDT signals. Traditional phase-sensitive detection circuits use diodes with nonlinear effects, integrated analog switches with a certain output impedance, or FETs with a certain voltage drop when turned on. As a switch to control the input terminal of the operational amplifier, it has the disadvantage of affecting the signal processing accuracy of the operational amplifier. At present, AD598 is a single-chip phase-sensitive detection solution available on the market, but its unit price is relatively expensive, and it is not suitable fo...

AI Technical Summary

Problems solved by technology

Phase-sensitive detection circuits are usually used when processing LVDT signals. Traditional phase-sensitive detection circuits use diodes with nonlinear effects, integrated analog switches with a certain output impedance, or FETs with a certain voltage drop when turned on. As a switch to control the input terminal of the operational amplifier, there is a disadvantage of affecting the signal processing accuracy of the operational amplifier

At present, AD598 is a single-chip phase-sensitive detection solution available on the market, but its unit price is relatively expensive, and it is not suitable for occasions that require cost performance

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