KR20150068286A - Winding test device - Google Patents

Abstract

The present invention provides a winding test device, which allows a test to be accurately and rapidly performed with sufficiently high voltage to a coil for the test, which has low inductance. A winding test device (100) comprises: output terminals (151, 152), which may be connected with a coaxial cable (161) for applying voltage between terminals of a coil (M) to be tested; output terminals (153, 154), which may be connected with a coaxial cable (162) for receiving measurement voltage generated between the terminals of the coil (M) to be tested: an impulse voltage generation part (110), which generates impulse voltage applied to the terminals of the coil (M) to be tested and outputs the impulse voltage to the output terminals (151, 152); an inter-terminal voltage detecting circuit (120) for detecting a waveform of voltage generated between the terminals of the coil (M) to be tested; and a test controlling part (140), which determines the quality of the coil (M) to be tested according to the measured waveform and controls each part.

Description

WINDING TEST DEVICE

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding test apparatus for testing whether a winding part is good or bad.

Examples of the winding part having a winding include an inductor, a transformer, and a coil for generating a magnetic field. Such a winding part is widely used in electronic and electric devices.

Production of chip components is increasing due to the spread of smart phones and tablet terminals. Particularly, in order to extend the operation time of a battery, a chip inductor used for a power supply circuit or the like is improved in efficiency and has a low inductance, so that a large capacity and miniaturization are progressed and higher reliability is demanded.

Patent Literature 1 discloses a power supply apparatus that includes an impulse voltage generating means for applying an impulse voltage between terminals of a coil under test to be inspected and an inter-terminal voltage detecting means for detecting a waveform of a vibration voltage generated between the terminals of the coil to be tested, Electromagnetic wave detecting means for detecting an electromagnetic wave generated by a discharge of a coil, and display means for displaying the detected vibration voltage waveform and electromagnetic wave waveform.

Japanese Patent Application Laid-Open No. 2009-115505

However, such a conventional winding inspection apparatus has the following problems with respect to the test of a coil under test having a low inductance (for example, 1 μH or less).

When a test coil having a low inductance is tested, since the inductance is low, the pulse voltage applied by the test apparatus is lowered at both ends of the coil under test. Therefore, it is not possible to perform a withstand voltage test according to a high applied voltage. For example, the test coil with an ultra-low inductance of 1 μH or less could not meet the test of higher voltage (test voltage 1000 V) or more.

Further, in the conventional winding test apparatus, even if it is intended to measure the voltage attenuation waveform caused by resonance between the test circuit and the test coil due to application of the impulse voltage, the voltage attenuation waveform can not be obtained accurately because of low inductance. As a countermeasure, it is considered to attach a dummy capacitor for creating a resonance state to the test circuit, and to increase the period of the attenuation waveform. However, in the method of attaching the dummy capacitors, a response waveform according to the original characteristics of the test coil can not be obtained, a large electric energy is required for impulse voltage application, and as a result, the problem that the test can not be performed at high speed have.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a winding test apparatus capable of accurately and rapidly performing a test with a sufficiently high voltage with respect to a coil under test having a low inductance.

According to an aspect of the present invention, there is provided a test apparatus for testing a test coil, comprising: first and second output terminals connectable to a first coaxial cable that is a voltage application system test cable for applying a voltage between terminals of a test coil; Generating an impulse voltage for applying between a third and a fourth output terminal to which a second coaxial cable as a voltage detecting system test cable for receiving a measured voltage generated between terminals of the coil can be connected and a terminal of the coil to be tested, And an impulse voltage generating unit connected to the third and fourth output terminals for applying an impulse voltage at the impulse voltage generating unit to generate an inter-terminal voltage Terminal voltage detecting means for detecting a waveform of the test coil based on a measured waveform detected by the inter-terminal voltage detecting means, Wherein the inter-terminal voltage detection means is configured to detect a voltage difference between the inductance of the to-be-tested coil and the electrostatic capacitance between the third output terminal and the fourth output terminal And a measurement waveform including a back electromotive voltage is detected.

According to the present invention, since the back electromotive force is measured by the four-terminal measurement method using two coaxial cables, it is possible to perform the test accurately and at a high speed with a sufficiently high voltage in the test coil of low inductance.

1 is a block diagram showing a configuration of a winding test apparatus according to a first embodiment of the present invention.
Fig. 2 is a graph showing the relationship between the impulse voltage applied by the impulse voltage generating unit of the winding test apparatus according to the first embodiment, the inter-terminal voltage detected by the inter-terminal voltage detecting circuit when the impulse voltage is applied to the test coil, Fig. 6 is a waveform diagram of a current detected by the detection circuit. Fig.
Fig. 3 is a schematic view for explaining a four-terminal testing circuit using a coaxial cable of a winding testing apparatus according to the first embodiment, wherein (a) shows a four-terminal testing circuit of the present embodiment, ) Shows a two-terminal test circuit as a comparative example.
4 is a waveform diagram for explaining an impulse waveform test by a counter electromotive voltage in the winding test apparatus according to the first embodiment, wherein (a) shows an impulse waveform by the counter electromotive voltage of the present embodiment, , and (b) show an impulse waveform of an air core coil of 1 μH as a comparative example.
5 is a flowchart showing a voltage rising insulation breakdown test operation of the winding test apparatus according to the first embodiment.
6 is a waveform diagram for explaining a master waveform according to the voltage rising insulation breakdown test of the winding test apparatus according to the first embodiment.
Fig. 7 is a waveform diagram for explaining the judgment value of the test result of the winding test apparatus according to the first embodiment. Fig.
Fig. 8 is a waveform diagram for explaining high-speed judgment by comparison of peak voltages of the winding test apparatus according to the first embodiment. Fig.
9 is a block diagram showing the configuration of a winding test apparatus according to the second embodiment of the present invention.
10 is a waveform chart for explaining an impulse evaluation method by controlling the applied current of the winding test apparatus according to the second embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment) Fig.

1 is a block diagram showing a configuration of a winding test apparatus according to a first embodiment of the present invention.

The winding test apparatus 100 shown in Fig. 1 applies pulse energy to the test coil M to be tested, pulses the voltage across the test coil M at that time, (Good or bad) of the signal M is determined.

Therefore, the winding test apparatus 100 includes the impulse voltage generating section 110 (impulse voltage generating means), the inter-terminal voltage detecting circuit 120 (inter-terminal voltage detecting means), the A / D converter 130 An output terminal 151 (first output terminal), an output terminal 152 (second output terminal), an output terminal 153 (third output terminal), an output terminal 154 (Fourth output terminal).

Test coils M are connected to the output terminals 151 to 154 of the winding test apparatus 100 via coaxial cables 161 and 162.

The present specification refers to an impulse voltage, an impulse current, or an impulse waveform as an electrical energy to be output in a pulsed manner.

[Impulse voltage generator 110]

The impulse voltage generating section 110 generates an impulse voltage and supplies the impulse voltage to the M coil to be tested. The high voltage generating circuit 111, the high voltage condenser 112, the high voltage switching circuit 113 including a thyristor, , And a gate pulse control circuit (114). The impulse voltage generating section 110 stores a high voltage impulse (pulse voltage) by storing the charge supplied from the high voltage generating circuit 111 in the high voltage capacitor 112 and switching the accumulated charge in the high voltage switching circuit 113 Occurs.

The high voltage generating circuit 111 charges the high voltage capacitor 112 with electric charge. The high-voltage generating circuit 111 generates a high voltage (usually several kV) to the extent that a general coil insulation test is possible.

The high-voltage condenser 112 accumulates the charge supplied from the high-voltage generating circuit 111 and instantaneously discharges the charge accumulated by the switching action (gate control) of the high-voltage switching circuit 113. The capacitor capacity of the high-voltage condenser 112 is, for example, 0.01 μF.

The high-voltage switching circuit 113 generates a high-voltage impulse by instantaneously discharging the charge accumulated in the high-voltage condenser 112 according to the switching action (gate control). The high voltage switching circuit 113 is composed of, for example, a thyristor. When the high voltage switching circuit 113 is composed of a thyristor, the anode (anode) is connected to the high voltage condenser 112, the cathode (cathode) is connected to the output side of the high voltage switching circuit 113, And a gate current flows from the gate to the cathode to turn on the anode and the cathode. Since the thyristor is automatically turned off at the time when a current flows in a direction opposite to the direction from the anode to the cathode, there is no need for a special circuit for turning off the thyristor. In addition, the high-voltage switching circuit 113 may be replaced with another switching element such as a MOSFET (metal-oxide-semiconductor field-effect transistor) instead of the thyristor.

The gate pulse control circuit 114 controls the on and off states of the thyristor by applying a predetermined pulse to the gate of the high voltage switching circuit 113 (here, the thyristor) in accordance with an instruction from the control unit 141. [

Here, the charge charged in the high-voltage capacitor 112 and the applied charge voltage become zero according to one high-voltage impulse generated in the impulse voltage generator 110. Accordingly, the high-voltage condenser 112 is capable of generating a continuous high-voltage impulse (pulse operation) if the high-voltage generating circuit 111 is made to constantly charge charges during a rest period of the high-voltage impulse.

[Terminal (terminal) voltage detection circuit 120]

The inter-terminal voltage detection circuit 120 is constituted by a voltage divider or the like and detects the voltage between the terminals of the coil M to be tested when the impulse voltage generated in the impulse voltage generating portion 110 is applied to the M coil (The voltage applied between the terminals, that is, the voltage between the terminals).

The inter-terminal voltage detection circuit 120 is connected to the output terminals 153 and 154 and the output terminals 153 and 154 are connected to the test coil M via a coaxial cable 162 having a capacitance (wiring capacitance C) Respectively. According to this configuration, the inter-terminal voltage detection circuit 120 detects the presence of the test coil M (M) between the terminals of the coil under test M when a high-voltage impulse is applied to the coil M to be tested in the impulse voltage generator 110 The inductance L of the test coil M and the electrostatic capacitance C of the coaxial cable 162 are measured by the inductance L of the test coil M and the capacitance of the coaxial cable 162 (Resonance oscillation voltage) oscillating at a resonance frequency depending on the capacitance (wiring capacitance C).

[A / D converter 130]

The A / D converter 130 converts the inter-terminal voltage of the coil under test M detected by the inter-terminal voltage detection circuit 120 into a digital signal and inputs it to the control unit 141 of the test control unit 140 do. As described above, the inter-terminal voltage includes the inductance (L) of the coil under test M, the back electromotive voltage generated by the capacitance (wiring capacitance C) of the coaxial cable 162 and the inductance L) and a voltage (resonance oscillation voltage) that oscillates at a resonance frequency depending on the electrostatic capacitance (wiring capacitance C) of the coaxial cable 162. In addition, the waveform of the terminal-to-terminal voltage including the counter-electromotive voltage and the resonance-voltage is collectively referred to as a measured (measured) waveform.

[Test control unit 140]

The test control unit 140 performs overall control of the entire winding test apparatus 100 and also controls the impulse voltage generation timing and the like of the impulse voltage generating unit 110 The waveform processing, the determination processing, and the waveform display processing. The test control unit 140 includes a control unit 141 (determination means and control means), a high voltage control circuit 142, an operation input unit 143, a display unit 144, and an external device control unit 145 do.

The control section 141 has a judgment function of judging both the portions of the coil under test M in accordance with the detected waveform of the M coil to be tested and a judging function of judging whether or not the impulse voltage generating section 110, And a control function for controlling the determination function. The control unit 141 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) and a RAM (Random Access Memory). The CPU executes a control program stored in the ROM in the RAM and executes the control function, Thereby realizing a control function.

The high voltage control circuit 142 outputs a control command for controlling the high voltage generation circuit 111 in accordance with the control signal from the control unit 141. [

The operation input unit 143 inputs various setting and operation information for performing the test of the M coil, and includes an operation button, an operation dial, a mode / range changeover switch, and the like.

The display unit 144 displays an applied voltage waveform, a current waveform, a measured waveform, a master waveform, a setting parameter, and a determination result for testing the M coil, for example, an LCD, a CRT display, .

The external device control unit 145 controls the processor (processor) that performs switching to the next chip inductor (test coil M) based on the completion signal from the control unit 141. [

[Output terminals (151 to 154)]

The output terminal 151 (first output terminal) is connected to the high potential side output of the impulse voltage generator 110 and the output terminal 152 (second output terminal) And is connected to the potential side output (GND in this embodiment). The output terminal 153 (third output terminal) and the output terminal 154 (fourth output terminal) are connected to the inter-terminal voltage detection circuit 120, respectively.

A coaxial cable 161 (voltage application system test cable) is connected to the output terminals 151 and 152 and a coaxial cable 162 (voltage detection system test cable) is connected to the output terminals 153 and 154. More specifically, the output side of the impulse voltage generating unit 110 is connected to one end of the test coil M via the output terminal 151 and the internal conductor 161a of the coaxial cable 161, The GND of the test coil 110 is connected to the other end of the coil under test M through the output terminal 152 and the outer conductor 161b of the coaxial cable 161. [ The measurement terminal of the inter-terminal voltage detection circuit 120 is connected to one end of the coil under test M via the output terminal 153 and the internal conductor 162a of the coaxial cable 162, 120 is connected to the other end of the coil under test M through the output terminal 154 and the outer conductor 162b of the coaxial cable 162. [ The inner conductor 161a of the coaxial cable 161 and the inner conductor 162a of the coaxial cable 162 are connected to one end of the coil M to be tested and the coaxial cable The outer conductor 161b of the coaxial cable 161 and the outer conductor 162b of the coaxial cable 162 are connected.

[Coaxial cable (161, 162)]

The coaxial cable 161 is a voltage applying system test cable constituting a path of a voltage applying system. The coaxial cable 162 is a voltage detecting system test cable constituting a path of the voltage detecting system. One terminal of the coaxial cable 161 is connected to the output terminals 151 and 152 of the coil testing apparatus 100 and the other terminal is connected to both ends of the coil under test M. One terminal of the coaxial cable 162 is connected to the output terminals 153 and 154 of the winding tester 100 and the other terminal is connected to both ends of the coil under test M.

As shown in Fig. 1, both ends of the output terminals 151 to 154 and the coil under test M are connected by four coaxial cables 161 and 162 in the winding tester 100 side.

The coaxial cables 161 and 162 have a capacitance (wiring capacitance C) and a resistance value (R). The coaxial cables 161 and 162 connected to the coil M to be tested are constituted by the inductance L of the coil M to be tested, the capacitance (wiring capacitance C) of the coaxial cables 161 and 162 and the resistance value R LCR circuit.

[Test coil (M)]

The test coil M is a coil part of an ultra-low inductance (1 μH or less) such as a chip inductor.

Hereinafter, the operation of the winding tester 100 configured as described above with reference to FIG. 2 (see FIG. 1 as appropriate) will be described.

First, the use of the impulse test of the winding test apparatus 100 will be described.

2 is a graph showing the relationship between the voltage applied across the terminals detected by the inter-terminal voltage detecting circuit 120 when an impulse voltage is applied by the impulse voltage generating section 110 and an impulse voltage is applied to the M coil, Fig. 7 is a waveform diagram of a current detected by the current detection circuit. Fig. The vertical axis represents voltage (V) and current (mA), and the horizontal axis represents time (占 sec). 2 shows the impulse waveform applied to the coil M to be tested on the left side, and the voltage and the current waveform on both ends of the coil M to be tested after the impulse waveform is applied to the right side of FIG.

The test coil M to be used in the measurement of the test waveform shown in Fig. 2 is a coil part having extremely low inductance (1 μH or less) and no magnetic saturation of the core. The applied voltage applied to the test coil M by the impulse voltage generator 110 is an impulse voltage of -10V. The application peak of this impulse voltage is -10V. The current waveform is later than the voltage waveform, and the current peak is -2.8A.

2, the impulse voltage generator 110 applies an impulse voltage of a negative polarity to the coil M to be tested.

(Iii) at the impulse voltage application starting time (i), the impulse voltage application peak (-10V), the current peak (about -2.8A), and the thyristor OFF point (iv) of the high voltage switching circuit 113 do. The above timings (i to iv) are one cycle of the applied waveform, and the applied pulse width is about 1.5 占 퐏 ec.

As shown in Fig. 2, when the test coil M is subjected to the application of an electric energy having an impulse voltage peak -10 V and a current peak of about -2.8 A within an applied pulse width of about 1.5 μsec, M), a peak voltage of -17 V at maximum is applied in an extremely short time.

As shown in Fig. 2, in one cycle (i to iv) of the applied waveform, the voltage waveform is almost symmetrical with respect to the zero point of the negative peak and the positive peak. The current waveform is delayed by about 90 degrees with respect to the voltage waveform, and the current is delayed due to overshoot, so that the thyristor turns OFF at the thyristor OFF point (iv) where the voltage waveform and the current waveform cross each other.

2, the electric energy stored in the M coil is turned off by the thyristor OFF, and the voltage becomes a voltage equal to or higher than the applied voltage, and the peak voltage at this time becomes the test voltage Set voltage). The peak voltage generated by this counter electromotive voltage is about -17V.

As shown in Fig. 2, a sharp spike-shaped pulse having this peak voltage becomes a waveform attenuating with time due to loss in the test coil M and loss of internal resistance. The voltage waveform is also called oscillating voltage because it oscillates, and the time until oscillation of the oscillating voltage stops is about 40 μsec.

When the high voltage impulse is applied to both ends of the coil M to be tested, both ends of the coil M to be tested are connected to the inductance L of the coil M to be tested and the wiring capacitance C of the coaxial cable 162 And then gradually attenuates while oscillating at a resonance frequency based on the inductance L of the coil M to be tested and the wiring capacitance C of the coaxial cables 161 and 162 A voltage (resonance oscillation voltage) is generated. The back electromotive voltage will be described later with reference to Fig.

Further, when the impulse voltage is applied, since the electric energy charged in the high-voltage condenser 112 (see FIG. 1) flows to the coil under test M at once, a large current flows in a very short time. However, in practice, the current flowing through the coil under test M is about one-tenth of the theoretical value due to the influence of the voltage drop due to the resistance component of each circuit portion and the internal resistance of the thyristor. Further, as in the waveform attenuation portion of FIG. 2, since the current is generated by the magnetic energy stored in the coil under test M after the thyristor is turned off, the current flowing through the coil under test M becomes small.

Next, a four-terminal measuring method using the coaxial cables 161 and 162 of the winding testing apparatus 100 will be described.

[Four-terminal measurement method using coaxial cables 161 and 162]

3 is a schematic diagram for explaining a four-terminal test circuit using the coaxial cables 161 and 162 of the winding test apparatus 100. Fig. Fig. 3 (a) shows a four-terminal testing circuit of the winding testing apparatus 100 of the present embodiment, and Fig. 3 (b) shows a two-terminal testing circuit as a comparative example.

First, a comparative example of Fig. 3 (b) will be described.

3 (b), the winding tester 10 of this comparative example has a high-voltage pulse power supply 11, a waveform measuring circuit 12, and output terminals 13 and 14, 13 and 14 and the test coil M are connected by a single coaxial cable 15. One of the terminals of the high voltage pulse power supply 11 and the waveform measuring circuit 12 is connected to the output terminal 13 and the other terminals of the high voltage pulse power supply 11 and the waveform measuring circuit 12 are all connected to the output terminal 14. [ Respectively. The output terminal 13 is connected to one end of the coil M to be tested through the internal conductor 15a of the coaxial cable 15 and the output terminal 14 is connected to the external conductor 15b of the coaxial cable 15 Is connected to the other end of the test coil (M).

The winding test apparatus 10 of the comparative example is a two-terminal test circuit having a common path between the application system and the detection system, and measures the applied waveform at both ends of the output terminals 13 and 14.

Therefore, the inductance component of the test cable (coaxial cable 15) to the coil under test M is included in the test. Further, if the length of the test cable (coaxial cable 15) becomes long, a high voltage can not be applied to both ends of the M coil. When voltage is applied to the test coil (M) having a low inductance, there is a problem that an appropriate voltage is not applied to both ends of the test object due to the voltage drop caused by the resistance of the wiring of the application system.

Next, the four-terminal testing circuit of the winding tester 100 shown in Fig. 3 (a) will be described.

As shown in Fig. 3 (a), the winding tester 100 uses a four-terminal measuring method (four-terminal testing circuit) using coaxial cables 161 and 162. [ The winding test apparatus 100 is provided with a path of a voltage applying system for applying an impulse voltage to the coil under test M and a path of a voltage detecting system for detecting a voltage between terminals at both ends of the coil M to be tested, . Specifically, in the winding test apparatus 100, the output side of the impulse voltage generating section 110 is connected to the output terminal 151 and the internal conductor 161a of the application coaxial cable 161 (voltage application system test cable) And the GND of the impulse voltage generator 110 is connected to the test coil M via the output terminal 152 and the external conductor 161b of the coaxial cable 161 for application, Respectively. The measurement terminal of the inter-terminal voltage detection circuit 120 is connected to one end of the test coil M via the output terminal 153 and the internal conductor 162a of the measurement coaxial cable 162 (voltage detection system test cable) And the measurement terminal of the inter-terminal voltage detection circuit 120 is connected to the other end of the test coil M via the output terminal 154 and the external conductor 162b of the coaxial cable for measurement 162. [

The coil testing apparatus 100 includes a path of a voltage applying system connecting the output side of the impulse voltage generating unit 110 and the output terminals 151 and 152 and the coaxial cable 161 to the coil under test M, Terminal test circuit having the path of the voltage detecting system connecting the input side of the inter-stage voltage detection circuit 120 and the output terminals 153 and 154 and the coaxial cable 162 to the coil under test M with different paths .

The winding test apparatus 100 applies a pulse-like high voltage (impulse voltage) to both ends of the coil under test M in accordance with the path of the voltage applying system. Then, a peak voltage or the like caused by a counter electromotive voltage appearing at both ends of the coil under test M is detected according to the path of the voltage detecting system.

Since the path of the voltage detecting system is not influenced by the path of the voltage applying system, the inter-terminal voltage occurring at both ends of the coil under test M can be measured without attenuation.

In addition, the path of the voltage applying system attenuates the voltage at both ends of the coil under test under the influence of wiring and the like, and since this voltage drop can be corrected by the path of the voltage detecting system, .

Two coaxial cables 161 and 162 are used to both ends of the coil M to be tested. Since the coaxial cables 161 and 162 are originally small in inductance and resistance values, the measurement accuracy can be increased.

Since the coaxial cables 161 and 162 are small in inductance and resistance values, it is difficult to be influenced by the cable length and a high voltage can be applied to both ends of the coil under test M. In other words, it is possible to increase the cable length of the coaxial cables 161 and 162, thereby improving convenience.

As described above, the terminal-to-terminal voltage at both ends of the coil under test M can be accurately measured by the four-terminal measuring method (four-terminal testing circuit) using the coaxial cables 161 and 162.

In the four-terminal measuring method, conventionally, there are a Kelvin terminal and a power supply circuit monitor terminal as a resistance measuring method. It is the purpose to correct the voltage drop by all the application system. The winding test apparatus 100 according to the present embodiment is capable of correcting the voltage drop by correcting the voltage drop due to resonance caused by the inductance L of the coil under test M and the wiring capacitance C of the coaxial cable 162 This is different from the conventional 4-terminal measurement method in that a back electromotive voltage and a resonance voltage are obtained.

In addition to the effect of making the path of the voltage detecting system and the path of the voltage applying system different from each other, in this embodiment, the coaxial cables 161 and 162 are used for the test cable (measurement cable) Waveform testing became possible.

[Impulse waveform test according to the back electromotive voltage]

4 is a waveform chart for explaining the impulse waveform test by the counter electromotive voltage of the winding tester 100. Fig. 4 (a) is a graph showing the impulse waveform by the counter electromotive voltage of the winding tester 100 of the present embodiment And FIG. 4 (b) shows the impulse waveform of the coercive coil of 1 μH as a comparative example. Fig. 4 shows an example in which an impulse voltage of a positive polarity is applied.

First, a comparative example will be described.

As shown in Fig. 4 (b), in the case of an air core coil of 1 μH, an impulse voltage is applied to detect the terminal-to-terminal voltage (oscillation) of both terminals of the air core coil. The larger the waveform of the voltage between the terminals, the higher the detection accuracy can be. However, like this air-core coil, the waveform of the inter-terminal voltage (oscillating voltage) is small and the damping is also fast in a single coil. As in this comparative example, when the inductance of the test body coil is low (for example, 1 μH or less), it is difficult to obtain a good measurement waveform of the coil of the test body. Therefore, it is necessary to add a separate resonance capacitor or apply an impulse of an excessive electric energy

On the contrary, the winding test apparatus 100 according to the present embodiment detects a spike-shaped response waveform consisting of a back electromotive voltage generated by turning on a thyristor by passing a current through both ends of the coil M to be tested. As shown in Fig. 4 (a), in the present embodiment, by using the coaxial cables 161 and 162, a spike-like response waveform consisting of an inverse voltage is generated in the inter-terminal voltage of the M coil. This back electromotive voltage is efficiently generated by the resonance (resonance) of the capacitance (refer to the wiring capacitance C in FIG. 3A) and the inductance (L) of the test coil M of the coaxial cables 161 and 162. The spike-shaped waveform of the back electromotive voltage is sensitive to the characteristics of the test coil M to be tested, so that a high sensitivity test can be performed as compared with the comparative example shown in Fig. 4 (b). In addition, a high voltage can be generated at both ends of the coil under test M even with the to-be-tested coil M having a low inductance according to the back electromotive voltage.

Here, if only a spike-shaped waveform is generated, it is possible to add a resonance capacitor. However, depending on which resonance capacitor is added, the measurement result may vary greatly. This embodiment realizes the back electromotive voltage without adding the resonance capacitor by using the electrostatic capacitance (refer to the wiring capacitance C in FIG. 3 (a)) of the coaxial cables 161 and 162. Further, in the present embodiment, since no resonance capacitor is added, a response waveform corresponding to the original characteristics of the coil under test M can be obtained, and a precise test can be performed. In addition, since the application of the impulse voltage does not require a large electric energy, the test can be performed at a high speed.

The conception using the wiring capacitance C of the coaxial cables 161 and 162 is first found by the present inventors in the four-terminal measuring method using the coaxial cables 161 and 162 described above. That is, the inventor of the present invention has found that since the coil M to be tested having a low inductance is low inductance, resonance can be achieved between a slight wiring capacitance C existing in the coaxial cables 161 and 162, (4-terminal test circuit) using the four-terminal measuring method using the four-terminal test circuit (161, 162). It has also been found that the coaxial cable does not satisfy the wiring capacity in one two-terminal test circuit, and the resonance does not occur.

[Master waveform registration]

During the evaluation of the withstand voltage of the test coil (M), if an excessive voltage is applied, the test coil (M) to be tested becomes an insulation breakdown.

In the present embodiment, in the voltage rising insulation breakdown test, the winding tester 100 memorizes all the waveforms obtained by applying the impulse voltage while gradually increasing the voltage, and stores the waveforms stored after the destruction of the M coil Lt; / RTI > Hereinafter, it will be described concretely with reference to the flow.

5 is a flowchart showing a voltage rise breakdown voltage test of the winding test apparatus 100. As shown in FIG.

First, in step S1, the control unit 141 sets the initial value of the voltage rising insulation breakdown test.

The impulse voltage generator 110 applies a high voltage impulse to both ends of the coil under test M via the output terminals 151 and 152 and the coaxial cable 161 in step S2. As described above, the coaxial cable 161 is a voltage applying system test cable constituting the path of the voltage applying system in the four-terminal measuring method (four-terminal testing circuit).

In step S3, the inter-terminal voltage detection circuit 120 detects the inter-terminal voltage (the inter-terminal voltage including the back electromotive voltage and the resonance voltage) of the coil under test M via the coaxial cable 162 and the output terminals 153 and 154 Is detected. Then, the A / D converter 130 converts the measured waveform detected by the inter-terminal voltage detection circuit 120 into a digital signal and inputs the digital signal to the control unit 141.

In step S4, the control unit 141 stores the measured waveform (digital data) of the coil under test M obtained by applying the impulse voltage according to the digital signal input from the A / D converter 130. [

When the high voltage impulse is applied to the coil M to be tested, the impedance value of the coil under test M is low at the beginning (at the beginning of the measurement), but in proportion to the current flowing through the coil M to be tested, The impedance value of the coil under test M becomes high due to resonance in the circuit or the like. The inductance L of the coil under test M and the capacitance of the coaxial cables 161 and 162 (see the wiring capacitance C in FIG. 3 (a)) between the terminals of the coil under test M An oscillating voltage (resonance oscillation voltage) is generated. The inter-terminal voltage detecting circuit 120 detects the inductance L of the coil under test M and the wiring capacitance C of the coaxial cable 162 connected to the output terminals 153 and 154 ) Is detected.

In step S5, the control unit 141 determines whether the coil under test M has undergone insulation breakdown. Details of the determination in the case where the test coil M is insulated and destroyed will be described later.

If the test coil M does not break down (step S5: No), the test control unit 140 performs control to increase the applied voltage from a low voltage to a high voltage by a predetermined voltage in step S6. More specifically, the control section 141 outputs a control signal for increasing the applied voltage from a low voltage to a high voltage to the high voltage control circuit 142. The high voltage control circuit 142 outputs the control signal to the impulse voltage generating section 110 The high-voltage generating circuit 111 of FIG. When the test coil M is insulated (step S5: Yes), the process proceeds to step S7.

In step S7, the control unit 141 reproduces the stored waveform after the destruction of the M coil, and ends this flow. Specifically, the control unit 141 outputs to the display unit 144 the voltage or the state of the breakdown that leads to the destruction of the test coil M after the breakdown of the M coil. Accordingly, even after the destruction of the coil M to be tested, the waveform information before reaching the stored destruction can be registered as an arbitrary waveform as comparison data with the master waveform (reference waveform).

Thereby, the voltage of the coil M to be tested and the state of the breakdown of the coil M to be tested can be known. Further, even after the test coil M is destroyed, the waveform information stored before the test coil M reaches the destruction can be registered as the master waveform (reference waveform).

6 is a waveform diagram for explaining a master waveform according to the voltage rising insulation breakdown test of the winding tester 100. In FIG.

By executing the voltage rising type dielectric breakdown test flow shown in Fig. 5, a master waveform (reference waveform) shown in Fig. 6 can be obtained. 6 shows an example in which the applied voltage is increased from the starting voltage of the applied voltage of 15 V to the ending voltage of 30 V in the 5 V step. Waveforms (V1 to V3) are waveforms before insulation breakdown. The waveform (V4) shows a state in which insulation breakdown occurs when the voltage is 25 V, and the waveform is attenuated. The waveforms V1 to V3 before the insulation breakdown in FIG. 6 have a sharp upward waveform 301 due to the resonance of the coil under test M and reach a maximum value, and then, through the monotone reduction waveform 302, The waveform 303 becomes. The waveform V4 in which the dielectric breakdown occurred in Fig. 6 does not have a sharp rising waveform or a vibration waveform. Therefore, it can be easily judged by the peak voltage PkStb, the waveform area Area and the waveform difference area Dif.Area, can do.

As described above, all the waveforms are preserved in the test while the applied voltage is increased, and it is possible to adopt a healthy waveform before dielectric breakdown as a master waveform (reference waveform) by regenerating later.

[Waveform determination without affecting deviation of the test coil (M)] [

In the existing test apparatus, the determination values (parameters for determining the positive product and the defective product) when comparing the measurement waveform with respect to the reference waveform are set as one fixed determination value on the positive side and the fixed value on the negative side, respectively. This results in a smaller determination margin when the tendency of the regular product deviates from the change in the lot of the test coil M or the like. That is, in the manufacturing process of the coil under test M, the test result of the coil under test M produced by the change of lot or the like may exceed the certain value continuously (or continuously). In this case, even when the test result exceeds the determination value, it has been found that the test coil M is often good. The characteristics of the coil component can be changed by mechanical factors such as the mounting position of the member and the bonding state. Generally, this is caused by changes in the lot. As a feature of the coil part, there is no problem depending on the application even if a test result exceeds the judgment value, and there is no inconvenience in actual installation. If such a test coil M is uniformly removed as a defective product, the defective product rate is increased, leading to an increase in manufacturing cost.

In the present embodiment, the determination value of the test result is set independently as the upper limit and the lower limit. As a result, the influence of the test result difference (shift of the judgment value) due to the lot difference or the like can be eliminated. Specifically, when the test result of the coil under test M exceeds the upper limit value continuously for a predetermined number of times, the upper limit value is shifted upward only by a predetermined width. If the test result of the test coil (M) still exceeds this upper limit value, it is determined to be a defective product. When the test result of the coil under test M does not exceed this upper limit value, it is judged that the coil under test M is a good product. When the test result of the coil under test M does not exceed the upper limit value after the shift, the upper limit value is returned to the original upper limit value. The same applies to the lower limit value.

7 is a waveform diagram for explaining the determination value of the test result of the winding test apparatus 100. Fig. In FIG. 7, the measured waveforms of the reference waveform (master waveform) and the test coil (M) coincide completely and appear as one waveform.

In the present embodiment, waveform area determination, waveform difference area (Dif.Area) determination, and peak voltage (PkStb) determination are used as the test result determination.

The determination of the waveform area is performed by comparing the area ratio of the reference waveform (master waveform) and the measured waveform of the test coil M with respect to the time axis to determine the good / defective product of the coil under test M. In the Area judgment, the upper limit value and the lower limit value of the judgment value of the measurement waveform of the M coil to be tested with respect to the reference waveform (master waveform) are respectively set to, for example, 10%, and when the test result is out of the judgment value by a predetermined percentage It is judged to be defective. Incidentally, as described above, in the present embodiment, the determination value of the Area determination is set independently as the upper limit and the lower limit.

The determination of the waveform difference area (Dif.Area) determines whether the test coil M is good or defective by comparing waveform differences between the reference waveform (master waveform) and the measured waveform of the coil under test (M). This waveform difference has a wave height value or a phase difference. In the Dif.Area judgment, the upper limit value and the lower limit value of the judgment value of the measured waveform of the coil under test M are set to, for example, 30% and 0%, respectively, The case is judged to be defective.

Determination of the peak voltage (PkStb) determines whether the test coil (M) is good or defective by comparing the measured waveform of the test coil (M) with the peak voltage of the reference waveform (master waveform). This peak voltage judgment makes it possible to make a high-speed judgment because the reference waveform (master waveform) and the peak voltages of the measurement waveform are compared with each other. In other words, since the peak voltage is a comparison of values, there is no delay due to signal processing like other determinations, and the waveform is the first waveform in the measurement waveform, and although it is a technique peculiar to this embodiment, The detection accuracy is high. In the PkStb judgment, the upper limit value and the lower limit value of the judgment value of the peak voltage of the test coil M with respect to the reference waveform (master waveform) are respectively set to, for example, 10% % Is determined to be defective. Incidentally, high-speed judgment by comparison of peak voltages will be described later with reference to Fig.

[High-speed judgment by peak voltage comparison]

The determination of the coil under test M using the peak voltage is advantageous in that calculation is easy and it is possible to determine at a high speed. The inventor of the present invention has confirmed that the difference in inductance of each test coil M in the comparison of the measurement waveforms of the reference waveform (master waveform) and the test coil M is remarkably exhibited at the peak voltage.

Fig. 8 is a waveform chart for explaining high-speed judgment by comparison of the peak voltages of the winding testing apparatus 100. Fig.

1) of the test control unit 140 compares the measured waveforms of the reference waveform (master waveform) and the test coil M with the peak voltage so that the good / defective products of the coil under test M .

8, the peak voltage of the measurement waveform 401 of the test coil M with respect to the peak voltage of the reference waveform (master waveform) 400 is a determination value (e.g., -10%) of the peak voltage, Lt; / RTI > In the case of the example of Fig. 8, the control unit 141 (see Fig. 1) determines that the coil under test M is a defective product.

In this embodiment, since the peak voltage to be compared is the peak voltage generated by the back electromotive voltage, the difference in the peak voltage to be compared is large, and therefore, the detection accuracy is high. Incidentally, in the conventional test apparatus, there was no judgment to compare the peak voltage generated by the back electromotive voltage.

The peak voltage determination is easy to perform, has no delay due to signal processing, and is a waveform that appears at the beginning of the measurement waveform, so that high-speed determination is possible.

[Parallel processing]

1, the impulse voltage generating unit 110 (see FIG. 1) of the winding tester 100 charges the high voltage capacitor 112 with the electric energy of the impulse voltage applied to the coil under test M And the voltage switching circuit 113 is turned ON (when the thyristor is used, TURN OFF of the thyristor), the impulse voltage is applied to the coil under test M. The inter-terminal voltage detection circuit 120 (see FIG. 1) detects the inter-terminal voltage of the M coil to be tested in the response waveform of the M coil and outputs the detected voltage to the A / D converter 130 1) to the digital signal, and inputs the digital signal to the control unit 141 (see FIG. 1) of the test control unit 140. The control unit 141 performs signal processing based on the measurement waveform converted into the digital signal to determine the good / defective product of the coil M to be tested. The time required for each step is examined.

When a thyristor is used for the semiconductor element using the high-voltage condenser 112 (0.011 mu F) in the winding tester 100 shown in Fig. 1, the capacitor charging time of the high-voltage condenser 112 is approximately 10 msec. Also, it is 2 msec for waveform acquisition between the terminal-to-terminal voltage detection time of the inter-terminal voltage detection circuit 120 and the input to the A / D converter 130. The waveform processing, judgment processing and waveform display by the control section 141 are approximately 8 msec. Therefore, the total test time of one test coil M is about 20 msec.

However, in recent chip inductor tests, a high-speed test is continuously demanded in combination with a processor device which becomes an external device control unit 145 (see Fig. 1). The high-speed test in this series is specifically to test 600 or more in a minute.

As described above, the high-voltage condenser 112 is charged during the series of test times (about 20 msec) required for charging the high-voltage capacitor 112, applying the impulse voltage, acquiring the waveform, waveform processing, The capacitor charging time (about 10 msec) takes the most time.

Therefore, when the test is continuously performed at a high speed, this capacitor charging time becomes an obstacle and unnecessary waiting time occurs.

Thus, in the present embodiment, parallel processing for overlapping capacitor charging time, waveform acquisition, waveform processing, determination processing, and waveform display is performed. Specifically, the winding test apparatus 100 charges the high-voltage condenser 112 (the first one cycle requires a charging time), applies the impulse voltage after completion of charging, and performs waveform acquisition. At this point, the control unit 141 (see Fig. 1) outputs a signal of completion of the application to the external device control unit 145 (see Fig. 1). The external device control unit 145 controls the processor (not shown) to switch to the next coil M to be tested based on the completion signal from the control unit 141. [

In other words, the control section 141 controls the operation of the waveform shaping section 120 before acquiring a waveform by the inter-terminal voltage detecting circuit 120 and the A / D converter 130 or before entering the waveform processing, The control unit 150 outputs a completion signal to the external device control unit 145 and starts charging the high voltage capacitor 112 for the next test coil M according to the high voltage control circuit 142. The control unit 141 acquires the waveform of the current coil M to be tested and performs waveform processing based on the waveform acquisition while the high voltage capacitor 112 for the next test coil M is being charged, Processing, and waveform display.

Thus, by setting the capacitor charging time (about 10 msec) to the total time (about 10 msec) between the waveform acquisition and waveform processing, the determination processing, and the waveform display processing, the cycle of the capacitor charging time (about 10 msec) (About 10 msec). When the determination result is output, the control unit 141 can perform the next impulse voltage application without waiting time because the charging of the high-voltage condenser 112 is completed.

[Tests not affected by the value of L]

The winding test apparatus 100 applies the impulse voltage to the M coil by four-terminal measurement using the coaxial cables 161 and 162 and determines the characteristic difference of the M coil to be measured Test. The determination process is a comparison between a reference waveform (master waveform) and a measured waveform of the M coil, specifically, a waveform area determination, a waveform difference (Dif.Area) determination, and a peak voltage PkStb ).

However, the following knowledge has been newly proved in any of the determination of Area (waveform area) determination, waveform difference (Dif.Area) determination, and peak voltage (PkStb) determination. That is, the difference between the small values of the inductance L of the test coil M is remarkably displayed on the measured waveform, and the waveform pattern between the reference waveform (master waveform) and the measured waveform is largely deviated. In other words, the waveform pattern changes in response to the value of the inductance L of the test coil M sensitively. It is useful in that the difference in the value of the inductance L of the test coil M is remarkably exhibited in the measured waveform in that accuracy of determination of the value of the inductance L is enhanced. However, even if there is a slight difference in the value of the inductance (L) of the coil under test M, the coil under test M may be a constant product. As a feature of the coil part, there is no problem according to the use and there is no inconvenience in actual installation. If the test coil M to be tested is removed uniformly as a defective product, the proportion of defective products increases, leading to an increase in manufacturing cost.

The inventor of the present invention has conceived that the difference in the value of the inductance (L) of the test coil (M) is ignored to some extent and the difference in the waveform pattern is judged.

In the present embodiment, the control section 141 obtains the amount of change in the waveform type of each of the reference waveform (master waveform) and the measurement waveform, and compares the ratios of the waveform changes of the respective waveforms. More specifically, the control unit 141 obtains a continuous waveform data string from the reference waveform (master waveform), differentiates the waveform data string to calculate a derivative value, and outputs the calculated derivative value to the entire reference waveform The sum value is stored in advance as a reference value. Similarly, the control section 141 obtains a series of waveform data strings in the measurement waveform of the coil under test M, differentiates the waveform data series to calculate a derivative value, and outputs the calculated derivative value to the entirety of the measurement waveform . Then, the control unit 141 calculates the ratio of the change amount of the waveform to the waveform change by comparing the reference value obtained from the reference waveform with the value obtained from the measurement waveform. For example, when the comparison result between the reference value obtained from the reference waveform and the value obtained from the measured waveform is less than or equal to the predetermined threshold value, the coil under test M is judged to be good, and otherwise, it is judged to be defective.

Thus, it is possible to determine whether the test coil M is good or defective by neglecting a slight difference in the value of the inductance L of the coil M to be tested.

The determination process is also performed on the structure of the test coil M that was difficult to determine even in the determination of the waveform area (Area), the waveform difference area (Dif.Area), and the peak voltage (PkStb) The defect can be detected. For example, when there is any defect in the insulating portion of the test coil M, electric charge is sandwiched with the surrounding material. In addition, such defects may degrade with time. This problem is difficult to determine in any of the waveform area determination, waveform difference area (Dif.Area) determination, and peak voltage (PkStb) determination, but according to this determination processing, It was confirmed by experiments that it can be detected.

 As described above, the winding tester 100 of the present embodiment includes output terminals 151 and 152 to which a coaxial cable 161 for applying a voltage between the terminals of the M coil to be tested can be connected, Generates an impulse voltage to be applied between the output terminals 153 and 154 connectable to the coaxial cable 162 for receiving the measured voltage generated between the terminals of the test coil M and the terminals of the coil under test M and outputs them to the output terminals 151 and 152 A terminal for detecting a waveform of a terminal voltage generated between the terminals of the coil under test M by being connected to the impulse voltage generating unit 110 and the output terminals 153 and 154 and applying the impulse voltage at the impulse voltage generating unit 110; And a test control section 140 for judging the parts of the coil under test M based on the measured waveforms detected by the inter-terminal voltage detection circuit 120 and controlling the respective parts . The inter-terminal voltage detecting circuit 120 detects a voltage drop due to resonance between the inductance L of the coil under test M and the wiring capacitance C of the coaxial cable 162 connected to the output terminals 153 and 154, To detect the measurement waveform.

According to this configuration, in this embodiment, the terminal-to-terminal voltage of both ends of the coil under test M can be measured more accurately by separating the voltage application system and the voltage detection system by the four-terminal test circuit. Concretely, a sufficient high voltage is applied between both terminals of the coil under test (M) having low inductance and DC resistance together with a coil part of ultra-low inductance (1 μH or less) such as chip inductor, M (dielectric breakdown test) can be performed. For example, 1000 V or more can be applied to the test coil (M) of 1 μH.

Further, by measuring the back electromotive voltage, high-speed testing can be performed at high speed, and the inherent characteristics of the test coil M can be measured. For example, it is possible to judge whether the coil under test M can be judged at the shortest test time 10 msec, and it can be used in a mass production line.

Generally, in the case of the chip inductor, the test coil (M) is required to have a resistance against current (heat generation, melting, etc.) and durability against voltage (withstand voltage and insulation, etc.) as a performance evaluation. The winding testing apparatus 100 can apply a high voltage without using a high frequency even when the impedance of the coil under test M is low. That is, the coil testing apparatus 100 applies a pulse-like high voltage to both ends of the coil M to be tested, so that even when the impedance of the coil under test M is low, The presence or absence of an interlayer insulation short-circuit between the electrodes can be tested. The winding test apparatus 100 can obtain the evaluation by applying the voltage and current for the withstand voltage test in a very short time of several microseconds.

It is very suitable to be applied to the test equipment for coil insulation such as chip inductor, power inductor, choke coil, motor coil, and coil with a small number of turns. In addition, the chip inductors are applicable to both a wire wound type and a film laminated type.

(Second Embodiment)

9 is a block diagram showing a configuration of a winding test apparatus according to a second embodiment of the present invention. The same constituent elements as those in FIG. 1 are denoted by the same reference numerals and the description of the duplicate elements is omitted.

9, the winding testing apparatus 200 further includes a low potential (potential) side output (GND in this embodiment) of the impulse voltage generating section 110 to the winding tester 100 of FIG. 1, A current detection circuit 220 (current detection means) provided between the output terminal 152 and the output terminal 152 for detecting a current applied to the coil M to be tested, And an A / D converter 230 for converting the signal into a signal.

As shown in FIG. 9, the control unit 141 of the test control unit 140 performs the test by designating the applied current to the coil M to be tested. More specifically, the current detection circuit 220 detects the impulse current by flowing to the coil under test M when the impulse voltage is applied. The detected current is converted into a digital signal by the A / D converter 230 and input to the control unit 141. The control unit 141 performs control to apply an appropriate current corresponding to the rating of the test coil M in accordance with the impulse current flowing into the M coil detected by the current detection circuit 220. [

The control unit 141 can perform a test in which an appropriate current corresponding to the rating of the M coil is applied when the impulse voltage is applied.

By measuring the impulse current, the characteristic difference inherent to the test object can be determined from the waveform of the voltage and the phase of the waveform of the current.

10 is a waveform diagram for explaining an impulse evaluation method by control of an applied current.

As shown in Fig. 10, the winding tester 200 measures the current flowing through the coil under test M when applying the impulse voltage, and displays the peak current value.

The winding test apparatus 200 can perform the test by setting the value of the peak current flowing through the coil under test M in addition to the test by setting the applied voltage.

Will be described in more detail.

The winding test apparatus 200 can switch between the voltage waveform mode and the current waveform mode during the test operation.

In the voltage waveform mode, a peak voltage value is designated and a reference waveform (master waveform) according to the voltage waveform is set.

In the current waveform mode, the peak current value is specified and the current is adjusted by the current waveform. Thus, the reference waveform (master waveform) by the voltage waveform is set.

As shown in Fig. 10, the current waveform can be introduced at the same time as the voltage waveform and repeatedly displayed as a waveform.

The current waveform mode is a master waveform setting that specifies a peak current value, and is automatically adjusted so as to become the input current value. The reference waveform (master waveform) is set by the voltage waveform that becomes the finally set current value.

As described above, in the present embodiment, the winding test apparatus 200 is provided with the current detection circuit 220 that detects the current applied to the coil M to be tested. Therefore, when the impulse test is applied, The test can be carried out by applying the appropriate current according to the rating. By measuring the impulse current, it is possible to know the characteristic difference inherent to the test object in the phase of the voltage waveform and the current waveform.

The present invention is not limited to the above-described embodiment, and includes other modifications and applications, as long as it does not deviate from the gist of the present invention described in the claims.

For example, the above-described embodiments are described in detail in order to facilitate description of the present invention, and the present invention is not limited thereto. It is also possible to replace some of the constitution of the embodiment with the constitution of another embodiment, and the constitution of another embodiment can be added to the constitution of another embodiment. It is also possible to add, delete, and replace other configurations with respect to some of the configurations of the embodiments.

The above-described components, functions, processing units, processing means, and the like may be implemented by hardware, for example, by designing some or all of them as an integrated circuit. It is to be noted that the above-described respective structures, functions, and the like may be realized by software for analyzing and executing a program realizing the respective functions of the processor. Information such as a program, a table, and a file for realizing each function may be recorded in a recording device such as a memory, a hard disk, or an SSD (solid state drive), or an IC (Integrated Circuit) card, a SD And can be held on a recording medium. Note that, in this specification, the processing steps describing the time series processing are not necessarily executed in a time-wise manner as well as the processing performed in a time-series manner according to the described order, but the processing executed in parallel or individually (for example, Processing or processing by an object).

Note that control lines and information lines (information lines) are considered to be necessary for explanation, and not all control lines and information lines are shown on the product. In practice, almost all configurations may be considered to be connected to each other.

100,200; Winding test equipment
110; The impulse voltage generator (impulse voltage generator)
111; The high voltage generating circuit
112; High-pressure condenser
113; High-voltage switching circuit
114; Gate pulse control circuit
120; Terminal voltage detection circuit (terminal-to-terminal voltage detection means)
130, 230; A / D converter
140; The test controller
141; The control unit (determination means, control means)
142; High voltage control circuit
143; Operation input section
144; Display portion
145; External device control unit
151; Output terminal (first output terminal)
152; Output terminal (second output terminal)
153; Output terminal (third output terminal)
154; Output terminal (fourth output terminal)
161; Coaxial cable (voltage application system test cable)
162; Coaxial cable (voltage detection system test cable)
220; The current detection circuit (current detection means)

Claims (11)

First and second output terminals connectable to a first coaxial cable which is a voltage application system test cable for applying a voltage between terminals of a test coil,
Third and fourth output terminals connectable to a second coaxial cable that is a voltage detecting system test cable for receiving a measured voltage generated between terminals of the coil under test,
An impulse voltage generating means for generating an impulse voltage to be applied between the terminals of the test coil and outputting the impulse voltage to the first and second output terminals,
Terminal voltage detecting means connected to the third and fourth output terminals for detecting a waveform of an inter-terminal voltage generated between the terminals of the to-be-tested coil by applying an impulse voltage in the impulse voltage generating means,
And determination means for determining whether the test coil is good or bad according to a measured waveform detected by the inter-terminal voltage detection means,
The inter-terminal voltage detecting means includes:
And a measurement waveform including a back electromotive voltage generated by resonance (resonance) between the inductance of the to-be-tested coil and the electrostatic capacity between the third output terminal and the fourth output terminal is detected Device. The method according to claim 1,
And the capacitance between the third output terminal and the fourth output terminal is the wiring capacitance of the second coaxial cable. The method according to claim 1,
Wherein the impulse voltage generating means includes a thyristor that is turned off by polarity inversion and generates an impulse voltage by turning off the thyristor. The method according to claim 1,
Wherein the judging means compares the master waveform by the reference coil and the measured waveform of the coil under test and judges whether the test coil is positive or negative according to whether the amount of deviation is equal to or larger than a predetermined value. 5. The method of claim 4,
Wherein the judging means judges whether each of the test coils is at least one of a waveform area, a waveform difference area, and a magnitude of a peak value of the master waveform and the measurement waveform. 5. The method of claim 4,
Wherein when the amount of misalignment is included in the range of upper and lower thresholds and the test coil is judged to be good and the determination of the failure of the test coil is continued for a predetermined number of times, In the direction of the winding axis. The method according to claim 1,
Wherein said determination means obtains a waveform data string from the master waveform, differentiates the waveform data string to calculate a derivative value, and stores a value obtained by adding the calculated differential value to the entire master waveform in advance as a reference value,
Obtaining a waveform data string from the measured waveform, calculating a derivative value by differentiating the waveform data string, obtaining a sum of the calculated differential value with respect to the entire measurement waveform,
Wherein the comparison means compares the reference value obtained from the master waveform with the value obtained from the measurement waveform, and judges that the test coil is a good product if the amount of misalignment is less than or equal to a predetermined threshold value, and otherwise judges it as a defective product. The method according to claim 1,
Wherein the impulse voltage generating means generates the impulse voltage by a capacitor charging process,
The control means for controlling the impulse voltage generating means, the inter-terminal voltage detecting means, and the determining means,
Wherein,
A capacitor-charging process in the impulse voltage generating means, a waveform obtaining process in the inter-terminal voltage detecting means, a waveform process and a determining process in the determining means,
Wherein at least one of the waveform acquisition processing, the waveform processing, and the determination processing is executed without waiting for completion of the capacitor charging processing. 9. The method of claim 8,
The control means controls the impulse voltage generating means to gradually raise the impulse voltage from a low voltage to a high voltage,
Wherein said determination means stores a measured waveform obtained by slowly raising the impulse voltage from a low voltage to a high voltage to reproduce the stored waveform after destroying the coil under test. The method according to claim 1,
Further comprising current detecting means for detecting a current flowing through the to-be-tested coil,
Wherein the control means controls the impulse voltage generating means so that the value of the current flowing through the coil under test is a predetermined current value based on the value of the current detected by the current detecting means . 11. The method of claim 10,
Wherein the current detecting means detects an impulse current flowing through the test coil,
Wherein the determination means determines the characteristics of the coil under test based on an impulse voltage applied to the coil under test and a phase (phase) of the impulse current.

Images