KR20030087327A - Detection system of magnetic permeability for ferrite core by induction formula of magnetic field - Google Patents

Abstract

PURPOSE: A system is provided to achieve improved yield rate and reliability by easily checking defects of the produced ferrite core through the comparison with the reference ferrite core. CONSTITUTION: A system comprises an oscillation unit(10) for generating an AC power of a preset frequency band; a magnetic permeability detection unit(20) for taking, as an input, the AC power oscillated from the oscillation unit, and detecting the degree of changes of the magnetic field passing through the objective ferrite core; an amplifier(30) for taking, as an input, values from the magnetic permeability detection unit, and amplifying the received values; a digital signal generating unit including a root mean square(50) and an ADC(60), wherein the digital signal generating unit receives the signals amplified by the amplifier, converts the received signals into a digital signal, and outputs the digital signal; and a computer(70) for displaying, on a monitor, the data output from the digital signal generating unit, and storing the relevant data if needed.

Description

Detection system of magnetic permeability for ferrite core by induction formula of magnetic field

The present invention relates to the measurement of the dispersion of the ferrite core in the parts of the deflection yoke, in particular, by measuring the characteristics of the ferrite core currently produced through the winding machine in the production line and detecting the dispersion of the ferrite core The present invention relates to a projection rate detection system of a ferrite core according to a magnetic field induction scheme for implementing a function of extracting a ferrite core.

In general, the primary parameters of the deflection yoke may be deflection characteristics. The most important component that determines this deflection characteristic is the ferrite core, so the permeability or dispersion of the ferrite core is the main characteristic that determines the characteristics of the deflection yoke.

Therefore, measuring the permeability of ferrite cores is very important in the manufacturing process of the deflection yoke. To date, there is no specific method for professionally measuring the permeability of ferrite cores. The method is proposed.

There are two methods of measuring the high frequency magnetic characteristics as described above, which are analog methods and digital methods. The analog methods are the classical methods, which use general oscilloscopes to convert the voltage into magnetic characteristic values and read them. Is impossible.

In addition, in the case of high frequency, in order to prevent heat generation of the specimen, desired waveform recording must be performed within the shortest time, so it is practically difficult to measure high frequency of several kilohertz or more with an analog method that cannot store data of measurement or computer control.

Therefore, at present, almost all of the high frequency magnetic characteristic measurement such as magnetic history curve and core loss at high frequency adopts digital method.

If you look at the digital method, you can install a computer with an A / D converter interface card and a high-speed data bus, use a digital oscilloscope, write a waveform using a dedicated digitizer, or digitize the power meter. There is a method of measuring only iron loss by providing a digitizing function, and a method of measuring a single measuring device with a built-in high-speed A / D converter circuit and a signal generator.

Therefore, the A / D converter interface card and a high-speed data bus equipped with a computer, and the method of recording waveforms using a dedicated digitizer have high vertical resolution and high frequency of MHz or more due to the limitation of sampling rate. It is difficult to measure and the system cost is disadvantageous.

In addition, the digitizing power meter uses the built-in A / D converter to digitize the signal so that iron loss can be measured in the range up to several hundred microseconds, which has the disadvantage of not being able to measure the hysteresis curve waveform. .

In addition, the method using a digital oscilloscope is a method of obtaining a hysteresis curve waveform by recording a signal waveform on an oscilloscope and loading it from a computer to process it. A high-speed A / D converter circuit and a signal generator are built in to make a single measurement device. The method of integrating the oscilloscope function and the computer function is selected and commercialized only the necessary functions, and the two systems have no choice but to measure core loss and hysteresis curve at frequencies above ㎒.

Therefore, it is not easy to measure the permeability of the ferrite core in the production process using a conventional digital measurement method, and in particular, the development of sensors and systems for measuring the permeability of the ferrite core is urgently required.

An object of the present invention for solving the problems of the prior art as described above relates to the measurement of the dispersion of the ferrite core (Ferrite Core) of the components of the deflection yoke, in particular, the characteristics of the ferrite core currently produced through the winding machine in the production line The present invention provides a projection rate detection system for a ferrite core according to a magnetic field induction method for implementing a function of extracting a poorly produced ferrite core by measuring and detecting a scattering of the ferrite core.

1 is an exemplary configuration of a high frequency magnetic characteristic detection system according to the prior art digital measurement method.

FIG. 2 is an illustration of a B-H curve in which ferrite is measured at a frequency of 1 MHz and an operating magnetic flux density of 0.1 T using the system shown in FIG. 1. FIG.

Figure 3 is an exemplary configuration of a projection rate detection system of a ferrite core according to the magnetic field induction method according to the present invention.

4 is an exemplary detailed configuration diagram of the permeability detection unit in the projection rate detection system illustrated in FIG. 3.

5 and 6 are exemplary views showing the position of the magnetic field sensor located in the ferrite core.

Features of the projection rate detection system of the ferrite core according to the magnetic field induction method according to the present invention for achieving the above object, the oscillator for generating an AC power of a predetermined specific frequency band; It is located on the magnetic flux path by the magnetic field formed in the horseshoe magnet, and receives the AC power of the specific frequency band oscillated from the oscillation part and generates the fluctuation amount of the magnetic field generated in the horseshoe magnet and passing through the ferrite core to be inspected. A permeability detector for detecting; An amplifier which receives the detection value detected by the magnetic permeability detector and amplifies it; A digital signal generator which receives the signal amplified by the amplifier, processes the signal, converts the signal into digital signals, and outputs the digital signal; And a computer for displaying the data output from the digital signal generator according to an arbitrary pattern on the monitor, and using the data as data on the throw ratio of the entire ferrite core to be stored and inspected if necessary. .

As an additional feature of the projection rate detection system of the ferrite core according to the magnetic field induction method according to the present invention for achieving the above object, the permeability detection unit and a horseshoe magnet for forming a magnetic field; The amount of fluctuation of the magnetic field that is present on the magnetic flux path by the magnetic field generated in the horseshoe magnet and is generated from the horseshoe magnet through the ferrite core to be inspected by receiving an AC current source of a specific frequency band oscillated by the oscillation unit. It consists of a Hall sensor for detecting the.

The above object and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

First, a technical idea applied to the present invention will briefly look at the technology of Korean Patent Registration No. 10-0231887, which is a high frequency magnetic characteristic detection system according to a digital measurement method, which has been proposed in advance to solve the problems of the prior art. Shall be.

1 is a block diagram illustrating the prior art, the configuration of which is a signal for outputting a signal waveform corresponding to a measurement process by receiving parameters for the measurement conditions of the sample 3 to be measured from the computer 8. A signal generator 1 as an input device; A power amplifier (2) for amplifying the signal waveform output from the signal generator (1); A shunt 7 for outputting an H field voltage waveform with the current of the primary coil 4 of the sample 3 as a voltage; The H field voltage waveform converted from the classifier 7 is input through channel 1 and the B field voltage waveform induced in the secondary coil 5 of the sample 3 is input through channel 2 of each channel. The high frequency waveform is digitally sampled and stored in its own memory, and the voltage of the high frequency waveform of each channel is analyzed to determine core loss and magnetic value at the desired frequency and magnetic flux density according to the measurement conditions of the sample (3). And a digital oscilloscope 6 for measuring the magnetic hysteresis curve; In order to obtain a waveform corresponding to the measurement condition by receiving parameters for the measurement condition, the output of the signal generator 1 and the measurement value of the digital oscilloscope 6 are fed back to the signal generator 1. It determines the output, and instructs the digital oscilloscope to store the voltage waveforms corresponding to each of the H and B fields generated from the determined signal generator (1) signal, and loads the stored waveform into the internal memory of the computer to integrate the unit. A computer 8 which is responsible for the management and control of the overall system, such as obtaining measured values and H, B waveforms, and high frequency magnetic hysteresis curves through the numerical operation of; GPIB cable (9) between the GPIB (General Purpose Interface Bus) and the digital oscilloscope (6), a built-in communication interface for communication between devices of a series of control commands and numerical data, and between the GPIB and the signal generator (9). It is composed of

In the operation of the conventional system having the above configuration, when the signal waveform is output from the signal generator 1, the power amplifier 2 amplifies it, and the amplified current flows through the primary coil 4 of the sample 3. Magnetic field occurs. The H field generates the B field in the sample 3, and the induced voltage is generated in the secondary coil 5, and the current of the primary coil 4 is supplied to the channel 1 of the digital oscilloscope 6 by the classifier ( 7) is converted into a voltage through the input 7, the induction voltage of the secondary coil (5) is input to the channel 2.

The digital oscilloscope 6 digitally samples the high frequency waveform of each input channel and stores it in its own memory, analyzes the voltage of the high frequency waveform of each channel, and analyzes the desired frequency and magnetic flux density according to the measurement conditions of the sample (3). The core loss, magnetic value and the hysteresis curve in the

The computer 8 manages and controls each measurement process of the entire system. First, a parameter of a measurement condition is input from a measuring person to obtain a waveform corresponding to the measurement condition. The output and the measurements of the digital oscilloscope 6 are fed back to finally determine the signal generator 1 output.

The computer 8 also instructs the digital oscilloscope 6 to store voltage waveforms corresponding to the H and B fields generated from the determined signal generator 1 signal, and stores the stored waveforms into the computer 8 internal memory. Load and obtain the measured value, H, B waveform, and high frequency magnetic hysteresis curve through numerical operation such as integration.

The movement of this series of control commands and numerical data is via a GPIB cable 9 connected to the signal generator 1 and the digital oscilloscope 6 via a computer 8 built-in General Purpose Interface Bus (GPIB).

FIG. 2 shows a B-H curve in which a ferrite is measured at a frequency of 1 MHz and an operating magnetic flux density of 0.1 T using the system.

At this time, the above-described prior art method has a main point in the method of measuring the permeability of any material or device by measuring the BH curve, and measure the characteristics of the ferrite core currently produced through the winding machine in the production line Detecting the scattering of the ferrite core has a number of practical problems to be able to extract the ferrite core produced poorly.

Therefore, in the present invention, rather than using the BH curve as in the prior art described above, a certain magnetic field is directly applied to an arbitrary position of the ferrite core, and in this case, it is possible to measure the dispersion of the magnetic field passing through the ferrite core. The measurement sensor and its measurement system are intended to escape complex configurations as in the prior art described above.

In particular, existing ferrite cores are divided into soft ferrites and hard ferrites. The ferrite cores currently used in DY are soft cores, and the important characteristic of the ferrite cores is important in terms of permeability.

Ferrite cores used in the current DY should also be ferrite cores with a uniform permeability distribution without scatter, but in reality, they have a permeability distribution.

Therefore, we want to develop a ferrite core measuring device that can measure and detect this dispersion. In other words, by measuring the permeability of the ferrite core and measuring the per-part dispersion of the ferrite core, the defect of the ferrite core is detected to reduce the assembly and component dispersion of the DY.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a configuration example of a projection rate detection system for a ferrite core according to a magnetic field induction method according to the present invention. The oscillation unit 10 for generating an AC power of a predetermined specific frequency band and a magnetic field formed from a horseshoe magnet (not shown) Permeability that is present on the magnetic flux path by and receives the alternating current of the specific frequency band oscillated by the oscillation unit 10 and detects the amount of fluctuation of the magnetic field generated through the ferrite core to be inspected by the horseshoe magnet. The detector 20, the amplifier 30 that receives the detection value detected by the magnetic permeability detector 20 and amplifies it, and receives the signal amplified by the amplifier 30 to process the signal and convert it to digital It consists of RMS (50) and ADC (60) to output, and displays the data output from the ADC (60) in accordance with any pattern on the monitor Data comprises a computer 70 to which It can be used as a material for the throw ratio of the entire ferrite core for inspecting the storage as necessary.

Looking at the detailed operation of the permeability detection unit 20 for detecting the projection rate of the ferrite core in the projection rate detection system of the ferrite core according to the magnetic field induction method according to the present invention configured as described above, 4 is an exemplary diagram illustrating a detailed configuration of the permeability detection unit in the projection rate detection system illustrated in FIG. 3, and FIGS. 5 and 6 are exemplary views illustrating positions of magnetic field sensors located in a ferrite core.

Accordingly, the permeability detection unit 20, which is referred to as reference numerals 21 and 22 of FIG. 4, is positioned at the sensor position as shown in FIGS. 5 and 6, which is a horseshoe magnet 22 for forming a magnetic field. And, which is present on the magnetic flux path by the magnetic field generated in the horseshoe magnet 22 and receives the AC power of a specific frequency band oscillated by the oscillator 10 is generated in the horseshoe magnet through the ferrite core to be tested It is comprised by the hall sensor 21 which detects the degree of the fluctuation | variation of the magnetic field.

At this time, the detection method adopts a method in which the magnetic flux proportional to the magnetic permeability of the ferrite core is detected by the Hall sensor 21 by the magnetic flux from the N pole, since the Hall sensor 21 is driven using a current source. Noise influence by the oscillation unit 10 can be eliminated.

Thus, if the permeability of the ferrite core is constant in all parts, the value measured by the sensor will also be constant, and if the permeability of the ferrite core is not constant and will have scatter, the measured value will be different.

Therefore, after the computer 70 recognizes the amount of current flowing through the magnetic field sensor 22 that has been digitally converted in the ADC referred to by reference number 60, the computer 70 recognizes the amount of current, stores it, displays it on a monitor, and measures the dispersion of the reference ferrite core. It is possible to distinguish between defective and good products.

At this time, RMS, which is referred to by reference numeral 50, is a ROOT MEAN SQUARE, which is required to change the AC signal to the DC level, which is an ADC whose value is changed to the DC level 60 to digitize the data. Since the input to the RMS (50) is to convert the AC signal to a DC value.

Since a device commonly referred to as an A / D converter is collectively referred to as RMS and ADC, a detailed description thereof will be omitted.

While the invention has been shown and described in connection with specific embodiments thereof, it is well known in the art that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the claims. Anyone who owns it can easily find out.

When the projection rate detection system of the ferrite core according to the magnetic field induction method according to the present invention as described above is provided, the magnetic permeability of each part of the ferrite core to be produced is detected and compared with the reference ferrite core on the basis of whether the good or bad Can be quickly identified, which can increase production yield and ensure reliability.

Claims (2)

An oscillator for generating an AC power in a preset specific frequency band; It is located on the magnetic flux path by the magnetic field formed in the horseshoe magnet, and receives the AC power of the specific frequency band oscillated from the oscillation part and generates the fluctuation amount of the magnetic field generated in the horseshoe magnet and passing through the ferrite core to be inspected. A permeability detector for detecting; An amplifier which receives the detection value detected by the magnetic permeability detector and amplifies it; A digital signal generator which receives the signal amplified by the amplifier, processes the signal, converts the signal into digital signals, and outputs the digital signal; And The computer may display data output from the digital signal generator according to an arbitrary pattern on a monitor, and the data may be used as data on the throw ratio of the entire ferrite core to be stored and inspected if necessary. Projection rate detection system of a ferrite core according to the magnetic field induction method. The method of claim 1. The magnetic permeability detector comprises a horseshoe magnet for forming a magnetic field; The amount of fluctuation of the magnetic field generated in the horseshoe magnet through the ferrite core that is generated in the horseshoe magnet by being input on an alternating current source of a specific frequency band oscillated by the oscillation part, which is present on the magnetic flux path by the magnetic field generated in the horseshoe magnet. Projection rate detection system of a ferrite core according to the magnetic field induction method, characterized in that the Hall sensor for detecting the.