JP2007108057A - Winding test device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a winding test device capable of detecting a minute insulation defect in the winding. <P>SOLUTION: The winding test device 1 serving for determing the state of a test winding M comprises the voltage impressing circuit 2 for impressing pulse voltage to the test winding M; the test circuit 3 on which the test winding M is mounted; the Op-Amp 43 for insulating inputting signals from the test winding M and for out putting the impedance converted signal; the A/D converter 44 for converting the signal outputted from the Op-Amp 43 into a digital signal; and the spike signal detection filter circuit 60 for detecting the spike signal corresponding to the defect in the test winding M where between the Op-Amp 43 and the A/D converter 44, the resistances R1, R2 and the capacitor C1 are provided for delaying the signal representing the resonance oscillation voltage generated in the test circuit 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a winding test apparatus that tests a winding component including a winding by applying a pulse voltage.

  Winding parts with windings include inductors, transformers, magnetic field generating coils, etc. Such winding parts are mounted on many electronic and electrical devices such as motors and CRT (Cathode Ray Tube). It is recognized as a long-life part that does not require replacement. When an electronic / electrical device equipped with such a winding component malfunctions and cannot be easily repaired, the winding component may be defective. If, for example, a defective insulation portion originally exists in the winding component before being mounted on an electronic / electrical device, the winding component is defective through the following process. Here, the defective insulation portion refers to a portion that causes a decrease in insulation that induces a failure of the winding component due to long-term use of the winding component. In other words, when the power supply of the electronic / electrical equipment in which this winding component is mounted is turned on / off, a sudden voltage fluctuation is applied to the winding component, and a small spark is instantaneously generated in a defective part of the winding component. . In such a state where sparks are generated by turning on / off the power supply, if the electronic / electric equipment is used for a long period of time, the defective insulation of the winding parts gradually deteriorates due to the spark, and finally the winding parts. A defect occurs in itself. As a result, the electronic / electrical device on which the winding component is mounted causes malfunction.

  Therefore, in order to detect whether or not a winding component has a defect before being mounted on an electronic / electrical device, a high voltage impulse (pulse voltage) is applied to the winding to be tested, A winding test apparatus (high voltage impulse application type winding test apparatus) for determining the state of the coil under test, that is, the quality of the coil under test from the waveform of the voltage generated in the coil is known ( For example, see Patent Document 1 and Non-Patent Document 1).

  An example of a conventional winding test apparatus is shown in FIG. FIG. 7 is a block diagram showing a configuration of a conventional winding test apparatus. As shown in FIG. 7, a conventional winding test apparatus 101 includes a pulse voltage application circuit 102, a test circuit 103, a resonant vibration voltage measurement circuit 104, and a winding pass / fail judgment apparatus 105, and is a test object. The state (good or bad) of the winding M to be tested is determined.

The pulse voltage application circuit 102 charges the high-voltage capacitor 122 with the charge supplied from the high-voltage power supply generation circuit 121, and conducts the charged charge with a switch circuit (such as a thyristor) 123, thereby causing a high-voltage impulse (pulse voltage). Is generated.
The test circuit 103 has a stray capacitance Cs and a resistance value, and is connected to the winding to be tested M. The test circuit 103 to which the winding to be tested M is connected is an LCR circuit composed of an inductance (L), a capacitance (Cs), and a resistance value (R). Therefore, when a high voltage impulse is applied, the coil under test M is gradually attenuated while vibrating at a resonance frequency based on the inductance L of the coil under test M and the electrostatic capacitance Cs of the stray capacitance. Voltage (resonance oscillation voltage) is generated.

The resonant vibration voltage measuring circuit 104 divides the resonant vibration voltage by the high-voltage capacitor 141 and the low-voltage capacitor 142, impedance-converts the signal indicating the divided resonant vibration voltage by the operational amplifier 143, and the A / D converter. 144 is converted into a digital signal. The signal (resonance oscillating voltage) converted into the digital signal is input to the winding quality determining device 105 and used for determining the state of the tested winding M.
The winding pass / fail judgment device 105 has a result that the inductance of the winding M to be tested changes from a normal value to an abnormal value when the winding M to be tested has a defect, and the resonance frequency and attenuation state change accordingly. Based on the input digital signal, the quality of the tested winding M is determined based on the phenomenon that the resonant oscillation voltage changes.
Utility Model Registration No. 2591966 (paragraphs 0018, 0019, FIG. 1) Shukazu Inoue and one other, “Development of a layer short tester for low-voltage small motor coils”, Mitsubishi Electric Industrial Times, No. 96, February 2000, p. 26-30

  Since the conventional winding test apparatus 101 uses the phenomenon that the inductance changes when there is a defect in the winding M to be tested as a determination principle, a minute insulation failure portion that does not change the inductance is a winding to be tested. When M exists, the resonance frequency and the attenuation state do not change. Therefore, there is a problem that it is difficult to detect a defective insulation portion that will cause deterioration of the tested winding (winding part) in the future.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a winding test apparatus capable of detecting a minute insulation failure portion inside a winding to be tested.

  The present invention has been devised to achieve the above object. First, the winding test apparatus according to claim 1 comprises a pulse voltage applying means for applying a pulse voltage to the winding to be tested, and the device under test. A test circuit to which a winding is mounted, an insulating means for insulating a signal input from the test circuit and outputting an impedance-converted signal, and a signal conversion for converting the signal output from the insulating means into a digital signal A winding test apparatus provided to determine a state of the tested winding, wherein the digital signal converted by the signal converting means includes: the insulating means and the signal converting means; A spike signal detection frame that includes a resistor and a capacitor in between, delays a signal indicating a resonant oscillation voltage generated in the test circuit, and detects a spike-like signal corresponding to a defect in the test winding. And configured to provide a filter circuit.

  According to this configuration, the winding test apparatus applies a pulse voltage to the winding to be tested by the pulse voltage applying means. Here, the test circuit has a predetermined resistance and stray capacitance between the wirings, and forms an RLC circuit together with the test winding. Further, the pulse voltage is a voltage (high voltage impulse) applied in an impact when the electric charge charged by a capacitor or the like is instantaneously released. When a current is passed through the coil under test (at the beginning of measurement), the impedance value of the coil under test is low, but in the test circuit (RLC circuit) in proportion to the current flowing through the coil under test. Due to resonance or the like, the impedance value of the winding to be tested becomes high, and a signal indicating a resonance oscillation voltage (a signal having a resonance frequency) is generated. Also, when there is a defect (insulation failure part) inside the winding under test, a minute spark or the like is generated, and a spike-like voltage fluctuation signal corresponding to this spark or the like is the rise of the signal indicating the resonance vibration voltage. It occurs at the same time.

Then, the winding test apparatus detects the spike-like voltage fluctuation signal corresponding to the defect inside the tested winding by separating and distinguishing from the rising edge of the signal indicating the resonance oscillation voltage by the spike signal detection filter circuit. A signal indicating a resonant oscillation voltage generated in the test circuit is delayed. This spike signal detection filter circuit includes a filter circuit having a resistor and a capacitor. As a result, the rise of the signal indicating the resonant oscillation voltage is delayed by a time depending on the time constant determined by the resistance value of the filter circuit and the capacitance value of the capacitor. On the other hand, the spike-like voltage fluctuation signal corresponding to the defect in the winding under test passes without being influenced by the filter circuit. As a result, the signal indicating the resonant oscillation voltage is separated from the spike-like voltage fluctuation signal at the rise. Here, when the capacitance of the capacitor included in the filter circuit of the spike signal detection filter circuit is increased, the signal indicating the resonance oscillation voltage is further attenuated. In this case, the signal indicating the resonance oscillation voltage and the spike-like voltage fluctuation signal can be more clearly separated when the signal indicating the resonance oscillation voltage rises. That is, when the signal rises, the difference between the waveform of the signal indicating the resonant oscillation voltage and the waveform of the spike-like voltage fluctuation signal increases. Here, since the insulating means is interposed before the spike signal detection filter circuit, even if the LCR eigenvalue of the RLC circuit formed in the test circuit changes and the resonance frequency changes, it is included in the spike signal detection filter circuit. The RC circuit is not affected and mutual interference is prevented. This insulating means is an impedance converting means for converting a high input impedance into a low output impedance, and is composed of, for example, an operational amplifier.
The winding test apparatus converts the signal that has passed through the spike signal detection filter circuit into a digital signal by the signal conversion means. As a result, in this digital signal, when a spike-like voltage fluctuation signal is separated and detected at the rising edge of the signal indicating the resonant oscillation voltage, the state of the winding under test can be determined to be no (defective). .

  The winding test apparatus according to claim 2 is the winding test apparatus according to claim 1, wherein the filter circuit included in the spike signal detection filter circuit has many delay elements due to a resistor and a capacitor. It is characterized by the following.

  According to such a configuration, in the winding test apparatus, the filter circuit included in the filter circuit for detecting the spike signal has a larger order of delay elements due to the resistor and the capacitor, that is, the total capacity of the capacitors included in the filter circuit. Is larger, the signal indicating the resonance oscillation voltage is more attenuated.

  The winding test apparatus according to claim 3 is the winding test apparatus according to claim 1 or 2, wherein the spike signal detection filter circuit includes a first waveform shaping circuit, an adder circuit, It was set as the structure provided with.

  According to this configuration, in the winding test device, the spike signal detection filter circuit shapes the waveform of the spike-shaped voltage fluctuation signal among the signals output from the insulating means by the first waveform shaping circuit. To do. Here, the first waveform shaping circuit includes a filter circuit having the resistor and the capacitor. For example, the first waveform shaping circuit delays and attenuates a signal indicating the resonance oscillation voltage input from the insulating means, and cuts the spiked voltage. It is composed of various circuit elements for emphasizing the bandwidth so that only the fluctuation signal is peak-held and the waveform becomes rectangular. Then, the spike signal detection filter circuit adds the signal output from the first waveform shaping circuit and the signal output from the insulating means by the addition circuit. The added signal is input to the signal converting means. According to this, since the waveform of the spike-shaped voltage fluctuation signal is shaped and added to the signal before waveform shaping, the waveform of the spike-shaped voltage fluctuation signal in the signal pattern (waveform) based on the added signal Is emphasized. In this way, by shaping into a rectangular voltage, it is possible to prevent a spike-like voltage fluctuation signal from being leaked in the subsequent signal conversion means.

  The winding test apparatus according to claim 4 is the winding test apparatus according to claim 3, wherein the spike signal detection filter circuit further includes a second waveform shaping circuit, and the addition circuit includes: The signal output from the first waveform shaping circuit and the signal output from the second waveform shaping circuit are added.

  According to this configuration, in the winding test apparatus, the spike signal detection filter circuit shapes the waveform of the signal indicating the resonance oscillation voltage among the signals output from the insulating means by the second waveform shaping circuit. To do. Here, the second waveform shaping circuit cuts a noise component (a spike-like minute voltage fluctuation signal, a high frequency component included in the resonance signal) from the signal input from the insulating unit, for example, and the first waveform shaping circuit. The signal level is adjusted so that the voltage value has the same level as that of the spike-like voltage fluctuation signal output from, and various circuit elements are used to emphasize the resonance signal. The spike signal detection filter circuit adds the signal output from the first waveform shaping circuit and the signal output from the second waveform shaping circuit by the addition circuit. The added signal is input to the signal converting means. According to this, since the spike-shaped voltage fluctuation signal and the signal indicating the resonance oscillation voltage are added after the waveform is shaped by the independent waveform shaping circuits, the signal pattern based on the added signal is added. Unnecessary noise components are removed from the (waveform).

  According to the first aspect of the present invention, since the signal indicating the resonance oscillation voltage generated when the generated pulse voltage is applied to the tested coil can be delayed, a minute insulation is provided inside the tested coil. When there is a defective part, the spike-like voltage fluctuation signal that occurs at the same time as the signal indicating the resonant vibration voltage rises can be separated from the signal indicating the resonant vibration voltage, and the state of the winding under test is determined to be NG (defective). Can be determined. Accordingly, since a minute insulation failure portion inside the winding to be tested can be detected, the quality of the winding component can be improved. As a result, it is possible to remove one of the causes of the malfunction of the electronic / electrical device on which this winding component is mounted, and to contribute to stable operation of the electronic / electrical device.

  According to the second aspect of the present invention, when the order of the delay element is increased, the signal indicating the resonant oscillation voltage and the spike-like voltage fluctuation signal can be more clearly separated.

  According to the invention described in claim 3 or claim 4, since the waveform of the spike-like voltage fluctuation signal is emphasized, the waveform display is improved. As a result, the accuracy of pass / fail judgment is improved.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
[Configuration of winding test equipment]
FIG. 1 is a block diagram of a winding test apparatus. As shown in FIG. 1, the winding test apparatus 1 performs a test for determining the state of the winding M to be tested (determining pass / fail), and includes a pulse voltage application circuit 2 and a test circuit 3. And a resonant vibration voltage measuring circuit 4 and a winding quality determining device 5.

  The pulse voltage application circuit (pulse voltage application means) 2 applies a high voltage impulse (pulse voltage) to the winding M to be tested, and includes a high voltage power source generation circuit 21, a high voltage capacitor 22, and a switch circuit 23. I have.

  The high voltage power generation circuit 21 is for charging the high voltage capacitor 22 with electric charges. In the high-voltage power generation circuit 21, a high voltage is used so that a general coil insulation test is possible (usually several kV).

  The high-voltage capacitor 22 generates a high-voltage impulse by charging the charge input from the high-voltage power generation circuit 21 and releasing the charged charge instantaneously by the switching action (gate control) of the switch circuit 23. It is.

  The switch circuit 23 discharges the electric charge charged in the high-voltage capacitor 22 instantaneously by a switching action (gate control). In addition, although the thyristor provided with each terminal of an anode, a cathode, and a gate was illustrated as the switch circuit 23, this is an example and you may comprise with other elements, such as MOSFET.

  Note that the electric charge charged in the high-voltage capacitor 22 and the applied charging voltage become zero by one high-voltage impulse generated from the pulse voltage application circuit 2. For this reason, the high voltage capacitor 22 can continuously generate a high voltage impulse (pulse operation) if the high voltage power generation circuit 21 is constantly charged during the high voltage impulse pause period. is there.

  The test circuit 3 is a circuit to which the tested winding M is attached. The test circuit 3 has a predetermined resistance and a stray capacitance Cs between the wirings. The winding M to be tested is, for example, an inductor, a transformer, a magnetic field generating coil, or the like.

  The resonant oscillating voltage measuring circuit 4 is configured such that when a high voltage impulse is applied from the pulse voltage application circuit 2 to the winding M to be tested, the inductance of the winding M to be tested and the test between the terminals of the winding M to be tested. This is a circuit for measuring a voltage that oscillates at a resonance frequency depending on the stray capacitance Cs of the circuit 3 for use (resonance oscillation voltage). As shown in FIG. 1, the resonant oscillation voltage measurement circuit 4 includes a high voltage capacitor 41, a low voltage capacitor 42, an operational amplifier 43, an A / D converter 44, and a spike signal detection filter circuit 60. .

  The high-voltage capacitor 41 and the low-voltage capacitor 42 constitute a voltage divider, and divide the resonance oscillation voltage by a predetermined ratio, and each has an electrostatic capacity corresponding to this voltage division ratio.

  An operational amplifier (also referred to as an insulation means or impedance conversion means) 43 insulates a signal (a signal indicating a divided resonance oscillation voltage) input from the test circuit 3 and outputs an impedance-converted signal. This is for transmission to the A / D converter 44.

  The A / D converter (signal conversion means) 44 converts the signal that has passed through the spike signal detection filter circuit 60 (the signal output from the operational amplifier 43) into a digital signal. The signal converted into a digital signal by the A / D converter 44 is input to the winding quality determining device 5 and used for determining the state of the winding M to be tested.

  The spike signal detection filter circuit 60 is a filter circuit (delay circuit) that is inserted between the operational amplifier 43 and the A / D converter 44 and is a combination of a capacitor C1 and resistors R1 and R2. The spike signal detection filter circuit 60 allows a spike-like voltage fluctuation signal (hereinafter referred to as a spike signal), which is noise, to pass as it is, and a signal indicating a divided resonance oscillation voltage (hereinafter referred to as a resonance signal). Is delayed and output to the A / D converter 44. Note that the frequency of the spike signal is extremely higher than the resonance frequency.

  The winding quality determination device 5 is realized by a dedicated microcontroller, a microcomputer or a computer having an input / output interface, a storage device, and an arithmetic device. This winding pass / fail judgment device 5 judges the state (pass / fail) of the winding M under test based on the digital signal input from the A / D converter 44. Here, the criterion for determining whether or not the state of the winding to be tested M is negative is associated with the presence of a minute insulation failure portion in the winding to be tested M. For example, the winding quality determination device 5 detects a voltage value (voltage value indicating a spike signal) larger than a voltage value indicating a resonance signal within a period determined by a time constant of the filter circuit 60 for detecting a spike signal. Next, it is determined that the state of the winding M to be tested is NO. The winding quality determining device 5 may display the measurement waveform on a display device (not shown) so that a user who observes the measurement waveform determines the quality of the winding.

[Operation of winding test equipment]
Next, the operation of the winding test apparatus 1 will be described with reference to FIG. FIG. 2 is a flowchart showing the operation of the winding test apparatus shown in FIG. First, the winding test apparatus 1 applies a high voltage impulse to the winding to be tested M by the pulse voltage application circuit 2 (step S1).

  When a high voltage impulse is applied to the winding M to be tested, the impedance value of the winding M to be tested is low initially (at the initial measurement), but the test circuit 3 is proportional to the current flowing through the winding M to be tested. The impedance value of the winding M to be tested becomes high due to resonance in the inside. A voltage (resonant vibration voltage) that vibrates at a resonance frequency depending on the inductance of the coil M to be tested and the stray capacitance Cs of the test circuit 3 is generated between the terminals of the coil M to be tested. Further, when a high voltage impulse is applied when a minute insulation failure portion exists in the winding M to be tested, a spark is generated in the insulation failure portion of the winding M to be tested. A spike signal is generated due to the spark.

  Then, the winding test apparatus 1 measures the resonance vibration voltage obtained by dividing the voltage across the terminals of the winding M to be tested by the resonance vibration voltage measuring circuit 4 (step S2). Specifically, the spike signal detection filter circuit 60 of the resonance vibration voltage measurement circuit 4 delays the rising of a signal (resonance signal) indicating the divided resonance vibration voltage and outputs the delayed signal to the A / D converter 44. To do. Here, when a spike signal is generated, the spike signal detection filter circuit 60 outputs the spike signal with almost no delay.

  Then, the winding test apparatus 1 determines the state (good or bad) of the tested winding M based on the digital signal input from the A / D converter 44 by the winding quality determination apparatus 5 and does not show the determination result. The data is output to the display device (step S3).

  According to this winding test apparatus 1, when a high voltage impulse is applied to the winding under test M, the spike signal detection filter circuit 60 causes almost no effect on the spike signal of the winding under test M. Since the resonance signal corresponding to the voltage between the terminals can be delayed, when the spike signal is detected at the rise time of the resonance signal, the state of the winding M to be tested can be determined to be no (defective). That is, it is possible to detect a minute insulation failure portion of the winding M to be tested corresponding to the spike signal.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, in the present embodiment, the spike signal detection filter circuit 60 has been described as a combination of the capacitor C1 and the resistors R1 and R2. However, the spike signal detection filter circuit 60 may be modified as shown in FIG. FIG. 3 is a diagram showing a modification of the spike signal detection filter circuit of the winding test apparatus shown in FIG. 1. FIG. 3A shows a case where the resistance on the operational amplifier side is removed, and FIG. If included, (c) shows the case of a secondary filter.

  As shown in FIG. 3A, the spike signal detection filter circuit 60a is obtained by removing the resistor (R1) on the operational amplifier 43 (see FIG. 1) side from the spike signal detection filter circuit 60.

  As shown in FIG. 3 (b), the spike signal detection filter circuit 60b has a coil L1 connected in series with the resistor R1 in the spike signal detection filter circuit 60, and the A / D converter 44 (see FIG. 1) side. The resistance (R2) is removed. Note that the coil L1 may be connected in parallel to the resistor R1.

  As shown in FIG. 3 (c), the spike signal detection filter circuit 60c has a capacitor C2 connected in parallel to the resistor R2 in the spike signal detection filter circuit 60 (see FIG. 1). Grounded. That is, the spike signal detection filter circuit 60c is a secondary filter. Similarly, a multi-order filter to which a capacitor is added may be configured. In this case, a resistor is inserted between adjacent capacitors so as to be in series with the resistors R1 and R2. According to this, since the resonance signal is attenuated more greatly as the order is larger, the resonance signal and the spike signal can be clearly separated at the rise of the resonance signal.

  In the present embodiment, the spike signal detection filter circuit 60 has been described as a filter circuit (delay circuit) in which a capacitor and a resistor are combined. However, as shown in FIG. Also good. FIG. 4 is a block diagram illustrating a configuration example of a spike signal detection filter circuit in the case of improving the display of the signal pattern.

  As shown in FIG. 4, the spike signal detection filter circuit 70 includes a spike signal emphasis circuit 71 and a noise removal circuit 72 as a waveform shaping circuit that performs optimum waveform shaping, as shown in FIG. And an adder circuit 73 for adding the outputs of.

  The spike signal enhancement circuit (first waveform shaping circuit) 71 is a circuit including a resistor and a capacitor, and shapes and emphasizes the waveform of the spike signal among the signals output from the operational amplifier 43 (see FIG. 1). As shown in FIG. 4, the waveform shaping circuit includes a filter circuit (delay circuit) 74, an offset circuit 75, a peak hold circuit 76, and a bandwidth enhancement circuit 77.

  The filter circuit (delay circuit) 74 includes, for example, a filter circuit (delay circuit) that combines a capacitor and a resistor, which is a feature of the present invention, and delays the resonance signal output from the operational amplifier 43 (see FIG. 1) to offset it. This is output to the circuit 75.

  The offset circuit 75 includes, for example, a MOSFET, and cuts the resonance signal attenuated by the filter circuit 74 at a predetermined offset level. When the signal output from the filter circuit 74 includes a spike signal, the offset circuit 75 removes the resonance signal and outputs only the spike signal to the peak hold circuit 76.

  The peak hold circuit 76 includes, for example, a comparator, a diode, a hold capacitor, etc., and holds (holds) the largest value in the spike signal input from the offset circuit 75 for a certain period of time. Output.

  The bandwidth enhancement circuit 77 includes, for example, a MOSFET, and shapes the edge of the spike signal waveform input from the peak hold circuit 76, emphasizes the bandwidth, and outputs the result to the addition circuit 73.

The noise removal circuit (second waveform shaping circuit) 72 is a waveform shaping circuit that removes noise from the signal output from the operational amplifier 43 (see FIG. 1) and shapes the waveform of the resonance signal. A removal filter circuit 78 and a level adjustment circuit 79 are provided.
The low-level noise removal filter circuit 78 includes, for example, a general low-pass filter circuit, and cuts the high-frequency component of the resonance signal output from the operational amplifier 43 (see FIG. 1) and outputs the cut signal to the level adjustment circuit 79. is there.

  The level adjustment circuit 79 is composed of, for example, an amplifier using an operational amplifier, and the maximum value of the resonance signal input from the low-level noise removal filter circuit 78 is the same as the maximum value of the signal output from the bandwidth enhancement circuit 77. The signal is adjusted to a level and output to the adder circuit 73.

  The adder circuit 73 is composed of, for example, an operational amplifier, and adds the spike signal output from the bandwidth enhancement circuit 77 and the resonance signal output from the level adjustment circuit 79 to add the A / D converter 44 (see FIG. 1). ).

  According to the spike signal detection filter circuit 70, the resonance signal and spike signal waveforms can be shaped and emphasized, so that the accuracy of pass / fail judgment can be improved. Further, when the signal pattern (waveform) of the resonance signal and spike signal is output to a display device (not shown), unnecessary noise components are removed from the signal pattern (waveform) based on the added signal, and the waveform display is performed. Improved. Thereby, the user of the winding test apparatus 1 can easily determine the quality of the tested winding M by observing the waveform. As a result, a configuration in which the pass / fail judgment in the winding pass / fail judgment apparatus 5 (see FIG. 1) of the winding test apparatus 1 is omitted is possible.

  If the noise of the signal output from the operational amplifier 43 (see FIG. 1) is small, the noise removal circuit (second waveform shaping circuit) 72 may be omitted. In this case, the adder circuit 73 adds the spike signal output from the bandwidth emphasis circuit 77 and the signal output from the operational amplifier 43 (see FIG. 1) to add the A / D converter 44 (see FIG. 1). Output to.

Next, examples in which the effects of the present invention have been confirmed will be described.
When using a winding test apparatus 1 of the present embodiment (see FIG. 1), a flat cathode ray tube deflection coil using a litz wire (hereinafter simply referred to as a deflection coil) is used as the test winding M. The pass / fail judgment result of the winding M to be tested was compared with the actual pass / fail state. Here, the litz wire is a conducting wire obtained by twisting a plurality of thin enamel wires into a bundle.

[Deflection coil contact / insulation test]
Using the winding test apparatus 1 (see FIG. 1), a high voltage impulse (pulse voltage) applied to the winding M to be tested is set to 2 kV (pp), and a contact / insulation determination test of the deflection coil is performed. It compared with the test result by the coil | winding test apparatus 101 (refer FIG. 7). In this case, the filter circuit 60 for detecting the spike signal has a capacitance value of 12 nF for the capacitor C1 and resistance values of the resistors R1 and R2 of 500Ω, and a resistance of 500Ω on the output side of the operational amplifier 43 in order to stabilize the operation of the operational amplifier 43. Was connected and grounded.

FIG. 5 is an external view of a deflection coil used for measurement, where (a) shows a non-defective product and (b) shows a defective product. As shown in (a) of FIG. 5, the coil lead wire 502 is bent on the insulating tape 501 in the non-defective winding M _{1 to} be tested. This test winding M ₁ ensures coil insulation.

Further, as shown in FIG. 5B, in the tested winding M ₂ that is a defective product, the lead wire 502 of the coil is bent at a position slightly shifted from the insulating tape 501. In the winding M _{2 to} be tested, the lead wire 502 is short-circuited (short-circuited). In addition, a deflection coil whose quality is not apparent at the time of measurement was also prepared. That is, a plurality of samples including those without the insulating tape 501 attached thereto were prepared.

  As a result of the contact / insulation determination test, a signal pattern (waveform) obtained by measuring a signal input to the A / D converter 44 (144) (see FIG. 1 (FIG. 7)) at the initial measurement will be described with reference to FIG. To do. 6A and 6B are diagrams showing signal patterns measured by a winding test apparatus, where FIG. 6A is a comparative example (good state), FIG. 6B is a comparative example (defective state), and FIG. (Good state), (d) shows an example (defective state). In FIG. 6, one scale on the horizontal axis that is the time axis (between solid lines) is 1 μs.

First, the test result by the conventional winding test apparatus 101 (refer FIG. 7) which is a comparative example is demonstrated. When a non-defective winding M ₁ (see FIG. 5A) is used (in the good state), the resonance signal has a sudden rising waveform 611 as shown in FIG. And after reaching the maximum value, it becomes a vibration waveform through a monotonically decreasing waveform 612.

Next, when the tested winding M ₂ (refer to FIG. 5B), which is a defective product, is used (in the case of a defective state), as shown in FIG. It has a rising waveform 621, and after reaching the maximum value, it becomes a vibration waveform through a monotone decreasing waveform 622. At this time, even if a spike signal is generated due to a small insulation failure portion, the waveform of the spike signal is mixed in with the sudden rising waveform 621 of the resonance signal, and is difficult to identify. In other words, in the conventional winding test device 101 (see FIG. 7), only the comparison of FIG. 6 (a) and (b) is not present small insulation defect portion under test winding M ₂ It is difficult to detect it.

Next, the test result by the winding test apparatus 1 (refer FIG. 1) which is an Example is demonstrated. When a non-defective product under test winding M ₁ (see FIG. 5A) is used (in the good state), as shown in FIG. 6C, the resonance signal is a spike signal detection filter circuit. 60 (see FIG. 1) makes the rise slow, and the waveform 631 at the time of the rise has a mountain shape. The rising waveform 631 indicates that the signal indicating the sudden rising waveform 611 shown in FIG. 6A is delayed. It should be noted that the waveform 631 at the time of rising reaches a maximum value, and then becomes a vibration waveform through a monotone decreasing waveform 632.

On the other hand, when the defective test winding M ₂ (see FIG. 5B) is used (in the defective state), the spike signal detection filter circuit 60 delays the resonance signal, thereby Separate the signal from the resonant signal. Therefore, as shown in FIG. 6D, in addition to the resonance signal waveform 641, a spike signal waveform 643 is generated immediately after the first measurement. The rising waveform 641 reaches a maximum value, and then becomes a vibration waveform through a monotonically decreasing waveform 642.

Waveform 643 of the spike signal indicates that the spike-like voltage variations due to small insulation defect portion due spark or the like has occurred in the tested winding M ₂ (see FIG. 5 (b)) Yes. That is, in the winding test apparatus 1 (see FIG. 1) of the present embodiment, the winding to be tested M ₂ (see FIG. 5 (b)) is obtained simply by comparing (c) and (d) in FIG. It is possible to easily detect the presence of a minute insulation failure portion.

  As a result of the contact / insulation determination test, it is difficult for the conventional winding test apparatus 101 to use the winding test apparatus 1 in the case of a deflection coil using a litz wire as the tested winding M. It was possible to easily determine whether the coil using the existing litz wire was good or bad (whether the layer was short-circuited).

It is a block diagram which shows the structure of the winding test apparatus which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the winding test apparatus shown in FIG. FIG. 8 is a diagram showing a modification of the filter circuit for detecting a spike signal of the winding test apparatus shown in FIG. 1, where (a) shows a case where the resistance on the operational amplifier side is removed, and (b) shows a case where a coil is further included. c) shows a case of a secondary filter. It is a block diagram which shows the structural example of the filter circuit for spike signal detection in the case of improving the display of a signal pattern. It is an external view of the deflection coil used for the measurement, (a) shows a non-defective product and (b) shows a defective product. It is a figure which shows the signal pattern measured by the coil | winding test apparatus, Comprising: (a) is a comparative example (good state), (b) is a comparative example (defective state), (c) is an Example (good state), (D) shows an example (defective state). It is a block diagram which shows the structure of the conventional winding test apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Winding test apparatus 2 Pulse voltage application circuit (pulse voltage application means)
21 High Voltage Power Supply Circuit 22 High Voltage Capacitor 23 Switch Circuit 3 Test Circuit 4 Resonant Vibration Voltage Measurement Circuit 41 High Voltage Capacitor 42 Low Voltage Capacitor 43 Operational Amplifier (Insulation Means)
44 A / D converter (signal conversion means)
5 Winding pass / fail judgment device 60 (60a, 50b, 60c), 70 Spike signal detection filter circuit 71 Spike signal enhancement circuit 72 Noise removal circuit 73 Addition circuit 74 Filter circuit 75 Offset circuit 76 Peak hold circuit 77 Bandwidth enhancement circuit 78 Low level noise elimination filter circuit 79 Level adjustment circuit M Winding under test Cs Stray capacitance C1, C2 Capacitor R1, R2 Resistance L1 Coil

Claims (4)

Pulse voltage application means for applying a pulse voltage to the winding under test;
A test circuit to which the winding to be tested is mounted;
Insulating means for insulating a signal input from the test circuit and outputting an impedance-converted signal;
Signal converting means for converting the signal output from the insulating means into a digital signal,
A winding test apparatus provided for the digital signal converted by the signal converting means to be used for determining the state of the winding under test,
A filter circuit having a resistor and a capacitor is provided between the insulating means and the voltage converting means, and a signal indicating a resonant oscillation voltage generated in the test circuit is delayed, thereby causing a defect in the winding under test. A winding test apparatus comprising a spike signal detection filter circuit for detecting spike-like voltage fluctuation signals corresponding to.   The winding test apparatus according to claim 1, wherein the filter circuit included in the spike signal detection filter circuit has a multi-order delay element due to a resistor and a capacitor. The spike signal detection filter circuit includes:
A first waveform shaping circuit for shaping a waveform of the spike-like voltage fluctuation signal among signals output from the insulating means, including a filter circuit having the resistor and a capacitor;
An adding circuit for adding the signal output from the first waveform shaping circuit and the signal output from the insulating means;
The winding test apparatus according to claim 1, further comprising: The spike signal detection filter circuit further includes a second waveform shaping circuit that shapes a waveform of a signal indicating the resonance oscillation voltage among signals output from the insulating means,
The winding test apparatus according to claim 3, wherein the adding circuit adds a signal output from the first waveform shaping circuit and a signal output from the second waveform shaping circuit.

Images