CN217155276U - Low-cost high-integration LVDT transmitter - Google Patents

Abstract

The utility model discloses a low-cost high integrated LVDT changer, including singlechip, double-pole double-throw switch, primary, first secondary and second secondary, the first expansion end of double-pole double-throw switch connects to the first ADC end or the second ADC end of singlechip through first change over switch, and the second expansion end of double-pole double-throw switch connects to the first ADC end or the second ADC end of singlechip through the second change over switch, and the control end of double-pole double-throw switch is connected with an IO end of singlechip; one end of the primary coil is connected with the DAC end of the single chip microcomputer, and the other end of the primary coil is grounded; one end of the first secondary coil and one end of the second secondary coil are connected with the first fixed end of the double-pole double-throw switch, and the other end of the first secondary coil and the other end of the second secondary coil are connected with the second fixed end of the double-pole double-throw switch. The utility model discloses in utilize double-pole double-throw switch to replace detection coil and its subsidiary circuit, reduced the volume of product, the cost is reduced.

Description

Low-cost high-integration LVDT transmitter

Technical Field

The utility model relates to a LVDT signal processing technology field especially relates to a LVDT changer of low-cost high integration.

Background

LVDT (linear Variable Differential transformer) is an abbreviation of linear Variable Differential transformer, belongs to a linear displacement sensor, and comprises a primary coil, two secondary coils, an iron core, a coil framework, a shell and other parts. The conventional LVDT conditioning circuit adopts an independent element to build a multi-harmonic oscillation circuit to generate a sinusoidal excitation signal, and conditions the LVDT signal through a three-winding transformer, as shown in FIG. 1, in the scheme, the number of independent elements is large, the miniaturization is difficult, and the number of fault points is large. In addition, the scheme has 3 coils, complex process and high cost.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome one or more not enough of prior art, provide a LVDT changer of low-cost high integration.

The purpose of the utility model is realized through the following technical scheme: a low cost, highly integrated LVDT transmitter, comprising:

a single chip microcomputer;

a double-pole double-throw switch, a first movable end of the double-pole double-throw switch is connected to a first ADC end of the singlechip or a second ADC end of the singlechip through a first switch, a second movable end of the double-pole double-throw switch is connected to the first ADC end of the singlechip or the second ADC end of the singlechip through a second switch, and a control end of the double-pole double-throw switch is connected with one I/O end of the singlechip;

one end of the primary coil is connected with the DAC end of the single chip microcomputer, and the other end of the primary coil is grounded;

one end of the first secondary coil is connected with a first fixed end of the double-pole double-throw switch, and the other end of the first secondary coil is connected with a second fixed end of the double-pole double-throw switch;

and one end of the second secondary coil is connected with the first fixed end of the double-pole double-throw switch, and the other end of the second secondary coil is connected with the second fixed end of the double-pole double-throw switch.

Preferably, the model of the single chip microcomputer is C8051F 350.

Preferably, the double-pole double-throw switch is an analog switch.

The utility model has the advantages that:

(1) the utility model utilizes the DAC of the single chip microcomputer to generate sinusoidal signals, and compared with the multivibrator built in the prior art, the frequency of the sinusoidal signals generated in the utility model is more stable;

(2) the utility model discloses in utilize double-pole double-throw switch to replace detection coil among the prior art and its accessory circuit (like first triode Q1, second triode Q2, first resistance R1 and first electric capacity C1 etc. in fig. 1), reduced the volume of product, simplified production technology, the cost is reduced.

Drawings

FIG. 1 is a schematic circuit diagram of a prior art LVDT conditioning circuit;

fig. 2 is a schematic circuit diagram of an embodiment of the LVDT transmitter of the present invention.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

Referring to fig. 2, the present embodiment provides a low-cost and highly integrated LVDT transmitter:

the LVDT transmitter comprises a single chip microcomputer U1, a double-pole double-throw switch S1, a primary coil T1, a first secondary coil T2 and a second secondary coil T3. In one embodiment, the model of the single chip microcomputer U1 is C8051F350, and other single chip microcomputers U1 with the same function can be selected according to requirements.

The single chip microcomputer U1 has a DAC terminal, a first ADC terminal, a second ADC terminal and an I/O terminal, a first movable terminal of the double-pole double-throw switch S1 is connected to the first ADC terminal of the single chip microcomputer U1 or the second ADC terminal of the single chip microcomputer U1 through a first switch, a second movable terminal of the double-pole double-throw switch S1 is connected to the first ADC terminal of the single chip microcomputer U1 or the second ADC terminal of the single chip microcomputer U1 through a second switch, and a control terminal of the double-pole double-throw switch S1 is connected to one I/O terminal of the single chip microcomputer U1.

The primary coil T1 has a first end and a second end, the first end of the primary coil T1 is connected with the DAC end of the single chip U1, and the second end of the primary coil T1 is grounded.

The first secondary coil T2 has a first end and a second end, the first end of the first secondary coil T2 is connected to the first fixed end of the double-pole double-throw switch S1, and the second end of the first secondary coil T2 is connected to the second fixed end of the double-pole double-throw switch S1.

The second secondary coil T3 has a first end and a second end, the first end of the second secondary coil T3 is connected to the first fixed end of the double-pole double-throw switch S1, and the second end of the second secondary coil T3 is connected to the second fixed end of the double-pole double-throw switch S1.

The integrated LVDT transmitter is realized by utilizing the characteristics of DAC and ADC of the single chip microcomputer U1 and matching with some simple circuits. The DAC of the singlechip U1 outputs a sinusoidal alternating current signal to excite the primary coil T1, and the sinusoidal alternating current signal generated by the singlechip U1 is stable and reliable and hardly influenced by the ambient temperature. The single chip microcomputer U1 controls the double-pole double-throw switch S1 according to the polarity change of the sinusoidal alternating current signal, the sinusoidal alternating current signals induced by the first secondary coil T2 and the second secondary coil T3 are shaped into direct current signals, and then the direct current signals are transmitted to the single chip microcomputer U1 to be supplied to the single chip microcomputer U1 integrated ADC sampling voltage.

In one embodiment, the double pole double throw switch S1 is an analog switch.

In one embodiment, the single chip microcomputer U1 further comprises an RS485 port, and the RS485 port is used for being connected with an external device to achieve communication between the single chip microcomputer U1 and the external device.

The foregoing is illustrative of the preferred embodiments of the present invention, and it is to be understood that the invention is not limited to the precise forms disclosed herein, and that various other combinations, modifications, and environments may be resorted to, falling within the scope of the invention as defined by the appended claims. But that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention, which is to be limited only by the claims appended hereto.

Claims (3)

1. A low cost, highly integrated LVDT transmitter, comprising:

a single chip microcomputer;

a double-pole double-throw switch, a first movable end of the double-pole double-throw switch is connected to a first ADC end of the singlechip or a second ADC end of the singlechip through a first switch, a second movable end of the double-pole double-throw switch is connected to the first ADC end of the singlechip or the second ADC end of the singlechip through a second switch, and a control end of the double-pole double-throw switch is connected with one I/O end of the singlechip;

one end of the primary coil is connected with the DAC end of the single chip microcomputer, and the other end of the primary coil is grounded;

one end of the first secondary coil is connected with a first fixed end of the double-pole double-throw switch, and the other end of the first secondary coil is connected with a second fixed end of the double-pole double-throw switch;

and one end of the second secondary coil is connected with the first fixed end of the double-pole double-throw switch, and the other end of the second secondary coil is connected with the second fixed end of the double-pole double-throw switch.

2. The LVDT transducer of claim 1, wherein the single chip microcomputer is of type C8051F 350.

3. A low cost, high integration LVDT transmitter according to claim 1, wherein the double pole, double throw switch is an analog switch.

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