CN217112515U

CN217112515U - Inductance measuring device

Info

Publication number: CN217112515U
Application number: CN202220329569.2U
Authority: CN
Inventors: 梁诚; 苑东康; 李晖
Original assignee: Nanjing Kanglun Electronic Co ltd
Current assignee: Nanjing Kanglun Electronic Co ltd
Priority date: 2022-02-18
Filing date: 2022-02-18
Publication date: 2022-08-02
Anticipated expiration: 2032-02-18

Abstract

The utility model discloses an inductance measuring device, which comprises a measuring circuit, a key circuit, a main control microprocessor, a digital display unit and a buzzing circuit; the key circuit, the measuring circuit, the buzzing circuit and the digital display unit are respectively connected with the main control microprocessor; the measuring circuit is based on an inductance measuring circuit of a capacitance three-point oscillation method, and a main control microprocessor reads the frequency quantity of the measuring circuit and converts the frequency into the inductance quantity to finish inductance detection. The circuit is simple, the cost is low, and the device is easy to be combined with a production line.

Description

Inductance measuring device

Technical Field

The utility model belongs to wire-wound inductance field, especially an inductance measurement device.

Background

In the inductance production line, the coiling of most inductance is automatic production line coiling, produces the damage that the line turnover in-process can appear inside magnetic ring in the automation production line coiling and inevitably, causes the nonconforming of inductance, and artificial selective examination also has the nonconforming article to leak the inspection and flows out with visual inspection, so just need carry out measurement one by one to the inductance.

The traditional inductance measuring method comprises an unbalanced bridge inductance measuring method and a balanced bridge inductance measuring method, and the modern inductance measuring equipment comprises a vector impedance measuring instrument and a capacitance three-point oscillation method for measuring the inductance. The speed of the unbalanced bridge inductance measuring method and the balanced bridge inductance measuring method is slow, and the instrument volume is large; the vector impedance measuring instrument has the advantages of complex circuit structure, heavy volume and high price, and is not suitable for an automatic inductance production line. The capacitance three-point oscillation method is used for measuring inductance by converting inductance into frequency, and the circuit is relatively simple and is easy to combine with a production line.

Disclosure of Invention

The to-be-solved technical problem of the utility model is to provide an inductance measuring device, the circuit is simple relatively, and is with low costs.

The utility model relates to an inductance measuring device, which comprises a measuring circuit and a master control microprocessor; and the measuring circuit is an inductance measuring circuit based on a capacitance three-point oscillation method.

The measuring circuit comprises a capacitance three-point type oscillating circuit and an FPGA frequency divider, wherein the capacitance three-point type oscillating circuit comprises capacitances C5, C6, C7-C9, an inductance LX1 to be measured, resistances R22-26, a transistor T1 and a transistor T2; the capacitor C5 is connected in series with the capacitor C9, the other end of the capacitor C5 is connected to the collector of the transistor T2, the midpoint of the capacitor C5 and the capacitor C9 is connected to the emitter of the transistor T2, the other end of the capacitor C9 is grounded, and the capacitors C7 and C8 are connected between the base of the transistor T2 and the ground in parallel; the inductor LX1 to be tested is connected between Vcc and the collector of the transistor T2, and the resistor R24 is connected between the collector and the base of the transistor T2;

the midpoint between the capacitor C5 and the capacitor C9 is also connected with a coupling capacitor C6, the other end of the capacitor C6 is connected with the base of a transistor T1, the emitter of the transistor T1 is grounded through a resistor R26, the collector of the transistor T1 is connected with Vcc through a resistor R23, a resistor R22 is connected between Vcc and the base of a transistor T1, and the emitter of a transistor T1 is connected with an FPGA frequency divider; the FPGA frequency divider is connected with the input end of the master control microprocessor.

Further, the utility model discloses an inductance measurement device still includes key circuit, and key circuit is connected with main control microprocessor for control main control microprocessor is to reading of measuring circuit frequency, and when the button was not pressed, microprocessor port level was the high level. When the key is pressed, the level of the port of the microprocessor is pulled down to the ground, and the microprocessor starts to read the frequency of the measuring circuit.

Furthermore, the key circuit comprises an exclusion resistor R20, an exclusion resistor R21, capacitors C1-C4 and switches S1-S4; the resistor exclusion R20 and the resistor exclusion R21 respectively comprise four resistors, the switches S1-S4 are respectively connected with the four resistors in the resistor exclusion R21 in series, the other ends of the four switches are all grounded, and the four capacitors are respectively connected with the four resistors in the resistor exclusion R20 in series and then respectively connected to the two ends of the four switches in parallel for discharging and preventing static electricity.

Further, the utility model discloses an inductance measurement device still includes the digital display unit for show inductance value.

Further, the utility model discloses an inductance measurement device still includes buzzing circuit for buzzing circuit sends buzzing sound when the inductance of surveying surpasss the inductance threshold value of settlement.

Has the advantages that: the utility model discloses an electric capacity three-point oscillation method of adoption carries out the inductance measurement, and the circuit is simple, and is with low costs, easily integrates with automation line, and the later stage can change manual measurement into gathering the automatic triggering signal, carries out automatic measure.

Drawings

Fig. 1 is a block diagram of the present invention.

Fig. 2 is a key circuit diagram.

Fig. 3 is a measurement circuit diagram.

FIG. 4 is a diagram of a master microprocessor and peripheral circuitry.

Detailed Description

The utility model provides an inductance measuring device, as shown in figure 1, comprising a measuring circuit, a key circuit, a main control microprocessor, a digital display unit and a buzzing circuit;

the key circuit, the measuring circuit, the buzzing circuit and the digital display unit are respectively connected with the main control microprocessor, and the key circuit is used for sending a signal for starting measurement to the main control microprocessor;

the measuring circuit is based on an inductance measuring circuit of a capacitance three-point oscillation method, and a main control microprocessor reads the frequency quantity of the measuring circuit and converts the frequency into the inductance quantity to finish inductance detection.

The digital display unit is used for displaying inductance values;

specifically, as shown in fig. 2, the key circuit includes a resistor pack R20, a resistor pack R21, capacitors C1 to C4, and switches S1 to S4, where the resistor pack R20 and the resistor pack R21 each include four resistors, the switches S1 to S4 are respectively connected in series with four resistors in the resistor pack R21, the four capacitors are respectively connected in series with four resistors in the resistor pack R20 and then connected in parallel to two ends of the four switches, and the other ends of the four capacitors are all grounded. In this embodiment, the capacitors C1-C4 are all 10 μ F, the resistors in the resistor bank R20 are all 10K Ω, and the resistors in the resistor bank R21 are all 1K Ω.

As shown in fig. 3, the measurement circuit includes a capacitance three-point oscillation circuit and an FPGA frequency divider, where the capacitance three-point oscillation circuit includes capacitances C5, C6, C7-C9, an inductance LX1 to be measured, resistances R22-26, a transistor T1, and a transistor T2;

the capacitor C5 is connected in series with the capacitor C9, the other end of the capacitor C5 is connected to the collector of the transistor T2, the midpoint of the capacitor C5 and the capacitor C9 is connected to the emitter of the transistor T2, the other end of the capacitor C9 is grounded, and the capacitors C7 and C8 are connected between the base of the transistor T2 and the ground in parallel;

the midpoint between the capacitor C5 and the capacitor C9 is also connected with a coupling capacitor C6, the other end of the capacitor C6 is connected with the base of a transistor T1, the emitter of the transistor T1 is grounded through a resistor R26, the collector of the transistor T1 is connected with Vcc through a resistor R23, a resistor R22 is connected between Vcc and the base of a transistor T1 to provide bias voltage for a transistor T1, and the emitter of the transistor T1 is connected with the FPGA frequency divider; the FPGA frequency divider is connected with the input end of the master control microprocessor. The peripheral circuits of the master microprocessor are shown in fig. 4.

The utility model discloses a specific inductance measuring process is as follows: the method comprises the steps that an inductor to be measured is placed in a measuring circuit, self-oscillation is formed in the measuring circuit, oscillation frequency is obtained from an emitting electrode of a transistor T1, after frequency division is carried out by an FPGA frequency divider, a main control microprocessor reads a frequency division signal of the measuring circuit, calculates actual frequency, further calculates inductance value according to the actual frequency, a digital display unit displays the inductance value, and a buzzing circuit sends buzzing sound when the measured inductor exceeds a set inductance threshold value.

Claims

1. The inductance measuring device is characterized by comprising a measuring circuit and a master control microprocessor;

the measuring circuit is connected with the master control microprocessor, and the measuring circuit is an inductance measuring circuit based on a capacitance three-point oscillation method;

the measuring circuit comprises a capacitance three-point type oscillating circuit and an FPGA frequency divider, wherein the capacitance three-point type oscillating circuit comprises capacitances C5, C6, C7-C9, an inductance LX1 to be measured, resistances R22-26, a transistor T1 and a transistor T2;

the capacitor C5 is connected in series with the capacitor C9, the other end of the capacitor C5 is connected to the collector of the transistor T2, the midpoint of the capacitor C5 and the capacitor C9 is connected to the emitter of the transistor T2, the other end of the capacitor C9 is grounded, and the capacitors C7 and C8 are connected between the base of the transistor T2 and the ground in parallel; the inductor LX1 to be tested is connected between Vcc and the collector of the transistor T2, and the resistor R24 is connected between the collector and the base of the transistor T2;

2. The inductance measuring device according to claim 1, further comprising a key circuit, wherein the key circuit is connected to the main control microprocessor.

3. The inductance measuring device according to claim 2, wherein the key circuit comprises a resistor R20, a resistor R21, capacitors C1-C4 and switches S1-S4;

the resistor exclusion R20 and the resistor exclusion R21 respectively comprise four resistors, the switches S1-S4 are respectively connected with the four resistors in the resistor exclusion R21 in series, the other ends of the four switches are respectively grounded, and the four capacitors are respectively connected with the four resistors in the resistor exclusion R20 in series and then respectively connected to two ends of the four switches in parallel.

4. The inductance measuring device according to claim 1, further comprising a digital display unit for displaying the inductance value.

5. The inductance measuring device according to claim 1, further comprising a buzzer circuit for sounding a buzzer when the measured inductance exceeds a set inductance threshold.