JP4728498B2 - Capacitor testing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a capacitor testing apparatus that performs tests such as a characteristic test, a reliability test, and a destructive test on a capacitor.
[0002]
[Prior art]
With regard to capacitors used for high-frequency applications in electronic circuits, tests for examining temperature rise, deterioration, breakdown, etc. due to high-frequency are performed with respect to characteristics, reliability, life, and the like. As a method for performing such a test, conventionally, a test method in which a high frequency power source and various measuring devices are connected to a capacitor to be tested and high frequency power is directly applied to the capacitor is used.
[0003]
On the other hand, in recent years, as a capacitor used for high-frequency applications, development and use of a capacitor used for higher-frequency and higher-voltage applications has been promoted. When testing such a capacitor, it is difficult to sufficiently test the characteristics at high frequency and high voltage required for the capacitor with the conventional method in which power is directly applied to the capacitor with only a high frequency power supply. It has become.
[0004]
[Problems to be solved by the invention]
As another test method performed by applying test power to a capacitor, there is a method of using a resonance coil without directly applying high-frequency power to a capacitor to be tested. In this test method, a series resonance circuit is configured by connecting a coil to a capacitor in series, a resonance state is generated while high frequency power is applied to the resonance circuit, and high frequency and high voltage test power is applied to the capacitor. Apply.
[0005]
Here, in the above-described high-frequency capacitor test, in order to apply a sufficiently high voltage test power to the capacitor, the series resonance circuit composed of the capacitor and the coil has a frequency that requires a test, and Therefore, it is necessary to apply high frequency power at a frequency at which the resonance state is sufficiently maintained.
[0006]
For example, in the capacitor test, the capacity of the capacitor to be tested varies during the test time performed by applying high-frequency test power. When the capacitance of the capacitor fluctuates in this way, the resonance frequency in the resonance circuit composed of the capacitor and the coil changes, and the resonance state may not be sufficiently maintained. At this time, the high frequency power applied to the capacitor cannot be maintained at a high voltage, and therefore, a problem arises that a necessary test cannot be reliably performed on the capacitor.
[0007]
The present invention has been made in order to solve the above-described problems. A test power at a desired frequency is applied to a capacitor to be tested at a sufficiently high voltage to ensure a necessary test. It is an object of the present invention to provide a capacitor testing apparatus that can be used for the following.
[0008]
[Means for Solving the Problems]
Co The capacitor test apparatus includes (1) a coil that is connected in series to a capacitor to be tested to form a resonance circuit, (2) an applied power generation unit that applies test power of a predetermined frequency to the resonance circuit, and (3) A resonance control unit that tracks a resonance state in the resonance circuit and controls the coil or the applied power generation unit so that the resonance state is maintained; It is good as composition .
[0009]
In the above-described capacitor testing apparatus, the test condition for the test power applied to the resonance circuit composed of the capacitor and the coil during the capacitor test is not constant during the test time, and the resonance state is automatically tracked by the resonance control means. To do.
[0010]
As a result, even when the resonance condition changes due to a change in the capacitance of the capacitor during the test time, the resonance state is satisfactorily maintained. At this time, for the capacitor to be tested, the high frequency power applied to the capacitor is kept at a sufficiently high voltage throughout the test time, and therefore, the desired frequency for the capacitor to be tested is The necessary test can be reliably performed by applying the test power at a sufficiently high voltage.
[0011]
As a method for tracking a resonance state in a resonance circuit including a capacitor and a coil, it is preferable that the resonance control unit tracks the resonance state by controlling the frequency of the test power applied by the applied power generation unit. In this way, by tracking the resonance state using the resonance frequency, it is possible to apply circuit elements and techniques used in the high-frequency circuit, and the circuit configuration of the apparatus is simplified.
[0012]
As another method for tracking the resonance state, there is a configuration in which the voltage of the test power applied by the applied power generation means is controlled. Such a method is effective when the difference between the frequency of the test power and the resonance frequency is small. Or there exists the structure which controls the inductance of a coil.
[0013]
The applied power generation means includes a DC power supply and an inverter that applies test power generated from the DC power supplied by the DC power supply to the resonance circuit. By using the inverter in this way, it is possible to efficiently generate and apply test power from a commercial power supply or the like with low loss to the resonance circuit.
[0014]
Alternatively, the applied power generation means includes a broadband power amplifier that applies test power generated by amplifying AC power having a frequency set within a predetermined amplification frequency band to the resonance circuit. Thereby, sufficiently high frequency test power can be generated and applied to the resonance circuit.
[0015]
Book A capacitor testing apparatus according to the invention includes: (a) a coil unit that includes a coil that is connected in series to a capacitor to be tested and constitutes a resonance circuit; Applied power generating means for applying a test power of a predetermined frequency to The coil unit has a built-in coil and is configured to be attachable to and detachable from the apparatus main body at a coil operation unit provided on the front panel on the front surface of the apparatus. It is characterized by that.
[0016]
In the capacitor test, test power can be applied to a resonant circuit consisting of a capacitor and a coil over a wider frequency range and voltage range in order to allow a wide range of characteristics to be tested for various capacitors. It is hoped to do. On the other hand, by setting the coil for configuring the resonance circuit as described above as a replaceable (detachable) coil unit, the capacitor to be tested has a desired frequency in a wide frequency range. It is possible to efficiently test a capacitor by applying high-frequency high-frequency power.
[0017]
At this time, it further comprises set detecting means for detecting the set state of the coil unit, and the applied power generating means may prohibit application of the test power to the resonance circuit when the set detecting means detects a set state failure. preferable. Thereby, the problem which generate | occur | produces by replacement | exchange of a coil unit can be prevented, and the safety | security of an apparatus can be improved.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a capacitor testing apparatus according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.
[0019]
FIG. 1 is a block diagram schematically showing the configuration of a first embodiment of a capacitor testing apparatus according to the present invention. The capacitor testing apparatus 1 according to the present embodiment applies a high-frequency test power at a desired frequency to a capacitor 11 to be tested at a sufficiently high voltage to perform a characteristic test, a reliability test, a destructive test, and the like. The test is performed, and includes a coil 12, an applied power generation unit 2, a resonance control unit 3, a detection unit 4, and a setting unit 5.
[0020]
The coil 12 is a resonance built-in coil that is connected in series to the capacitor 11 to be tested to form a resonance circuit. One terminal 12 a of the coil 12 is connected to the test terminal 11 a via the applied power generation unit 2. The other terminal 12b of the coil 12 is connected to the test terminal 11b.
[0021]
When testing a capacitor, as shown in FIG. 1, a capacitor 11 to be tested is connected between two test terminals 11a and 11b. Thereby, a series resonance circuit in which the capacitor 11 and the coil 12 are connected in series is configured, and application of high-frequency power to the capacitor 11 is performed using this resonance circuit.
[0022]
The applied power generator 2 is installed between the terminal 12a of the coil 12 and the test terminal 11a to which the capacitor 11 is connected as described above. The applied power generation unit 2 is supplied with predetermined power such as normal AC power from a commercial power source. The applied power generation unit 2 generates test power having a predetermined frequency and voltage by the amplification function and the like, and applies the test power to the resonance circuit including the capacitor 11 and the coil 12. The frequency, voltage, etc. of the test power are set automatically or according to the setting contents input from the setting unit 5.
[0023]
The operation of the resonance circuit composed of the capacitor 11, the coil 12, and the applied power generation unit 2 is controlled by the resonance control unit 3. That is, the resonance control unit 3 tracks the resonance state in the series resonance circuit including the capacitor 11 and the coil 12, and the coil 12 or the applied power so that the resonance state is maintained within a range sufficient for the capacitor test. One or both of the generation units 2 are controlled.
[0024]
Further, the electrical characteristics of the resonance state generated in the series resonance circuit of the capacitor 11 and the coil 12 are detected by the detection unit 4. In the detection unit 4 in the configuration example illustrated in FIG. 1, a voltage detection unit 41, a current detection unit 42, and a frequency detection unit 43 are provided.
[0025]
Among these detection units, the voltage detection unit 41 detects a voltage value applied to the capacitor 11 when power is applied. Further, the current detection unit 42 detects a current value supplied to the capacitor 11 when power is applied. Further, the frequency detection unit 43 detects a resonance frequency value in the resonance state. These detected values are used for determining the result of the capacitor test.
[0026]
FIG. 2 is a front view showing the configuration of an embodiment of the capacitor testing apparatus shown in FIG. The capacitor testing apparatus 1 includes a resonance circuit unit including a coil 12 and the like, a power unit including an applied power generation unit 2 and the like, and a control unit including a resonance control unit 3, a detection unit 4, and a setting unit 5 and the like. Yes.
[0027]
FIG. 2 shows a front panel provided on the front surface of the capacitor testing apparatus 1. This front panel is provided at the lower part of the resonance circuit panel 100 corresponding to the resonance circuit unit, the resonance circuit panel 100, the power panel 200 corresponding to the power unit, and provided at the upper part of the resonance circuit panel 100 and corresponds to the control unit. Control panel 300.
[0028]
The resonant circuit panel 100 includes a capacitor installation unit 110 and a coil operation unit 120. The capacitor installation section 110 is provided with test terminals 11a and 11b for connecting the capacitor 11 to be tested (see FIG. 1). Further, the capacitor installation part 110 is provided with a cover for preventing the capacitor 11 from being touched during the test.
[0029]
Further, in this embodiment, the coil 12 used in the resonance circuit for the capacitor test is a plug-in system that is provided with several taps having a low inductance value and that can be manually switched with several taps as one unit. As a result, the inductance of the coil can be changed between the taps, while the coil determined to be used for the test can be a fixed inductance.
[0030]
Correspondingly, the coil operation unit 120 is provided with six sets of coil terminals 121 of coil switching taps for switching the inductance of the coil built in the resonance circuit unit. Thus, by connecting the predetermined terminals with the short bar 122, it is possible to select a coil used for the resonance circuit and change its inductance. The coil operation unit 120 is provided with a cover for preventing the coil terminal 121 and the like from being touched during the test.
[0031]
The control panel 300 includes a main operation unit 310, a power operation unit 320, and a frequency operation unit 330.
[0032]
The main operation unit 310 is provided with a start switch 311 for starting a capacitor test, a stop switch 312 for stopping the capacitor test, and an abnormality display lamp 313 for displaying an abnormality such as an apparatus or a resonance state. In addition, a power switch 301 for turning on / off the power supply of the entire apparatus is provided at the lower left portion of the main operation unit 310.
[0033]
In this embodiment, a plurality of timer modes can be used for the capacitor test. The timer mode includes, for example, a manual mode in which both start and stop of the test are manually instructed, a timer mode in which the test is instructed according to a set timer setting time, a set cycle time, and a counter setting number of times. There is a cycle mode in which power is repeatedly applied. Correspondingly, the main operation unit 310 is provided with a timer operation unit 314, a counter operation unit 315, and a timer mode changeover switch 316.
[0034]
The timer operation unit 314 includes a display unit that displays a set timer setting time, an elapsed time during a test, and the like, and a setting operation unit that performs a setting operation such as a timer setting time as a test time. The counter operation unit 315 is used in the case of the cycle mode, and includes a display unit that displays the number of cycles and the like, and a setting operation unit that sets and operates the counter setting number that is the number of cycles. . The timer mode changeover switch 316 is a changeover means for changing over each timer mode described above.
[0035]
The power operation unit 320 includes a voltage display unit 321 that displays an applied voltage value detected by the voltage detection unit 41, a current display unit 322 that displays an energization current value detected by the current detection unit 42, and a voltage setting volume. 323.
[0036]
The voltage setting volume 323 is a voltage setting means for setting an output voltage, and by its operation, the voltage of the test power generated by the applied power generation unit 2 or a DC signal or AC used for generating the test power. Set or change the voltage or amplitude of a signal (sine wave signal) or the like.
[0037]
The frequency operation unit 330 is provided with a frequency display unit 331 that displays the resonance frequency value detected by the frequency detection unit 43.
[0038]
In this embodiment, a plurality of test modes can be used for the capacitor test. Examples of the test mode include an automatic resonance frequency detection tracking mode, a manual frequency setting resonance mode, and a manual frequency setting direct application mode. Correspondingly, the frequency operation unit 330 is provided with a frequency setting volume 332 and a test mode changeover switch 333.
[0039]
The frequency setting volume 332 is a frequency setting means for setting a frequency used in the case of the manual frequency setting resonance mode, and the frequency of the test power generated by the applied power generation unit 2 or the test by the operation. The frequency of the AC signal (sine wave signal) used for generating power is variably set or changed. The test mode changeover switch 333 is a changeover means for changing over each test mode described above.
[0040]
In the capacitor testing apparatus of this embodiment, a series resonance circuit is configured by connecting a coil 12 in series to the capacitor 11 without directly applying high frequency power from a high frequency power source to the capacitor 11 to be tested. A resonance state is generated while applying high frequency power to the resonance circuit, and high frequency and high voltage test power is applied to the capacitor 11. Further, the test condition for the test power applied to the resonance circuit composed of the capacitor 11 and the coil 12 during the test of the capacitor 11 is not constant during the test time, and the coil 12 or the applied power generation unit 2 is set by the resonance control unit 3. By controlling, the resonance state is automatically tracked.
[0041]
Thereby, even when the capacitance of the capacitor 11 fluctuates during the test time and the resonance condition changes, the resonance state is satisfactorily maintained. At this time, for the capacitor 11 to be tested, the high frequency power applied to the capacitor is maintained at a sufficiently high voltage throughout the test time, and therefore the capacitor is tested at a desired frequency. It is possible to apply the electric power at a sufficiently high voltage to reliably perform a necessary test.
[0042]
FIG. 3 is a block diagram schematically showing the configuration of the second embodiment of the capacitor testing apparatus. The configuration of the capacitor testing apparatus 1 of the present embodiment is the same as that of the first embodiment with respect to the coil 12, the applied power generation unit 2, the detection unit 4, and the setting unit 5.
[0043]
A display unit 6 is installed corresponding to the detection unit 4. In the display unit 6 in the configuration example illustrated in FIG. 3, a voltage display unit 61, a current display unit 62, and a frequency display unit 63 are provided.
[0044]
Among these display units, the voltage display unit 61 corresponds to the voltage display unit 321 in FIG. 2 and displays the applied voltage value detected by the voltage detection unit 41. The current display unit 62 corresponds to the current display unit 322 in FIG. 2 and displays the energization current value detected by the current detection unit 42. Further, the frequency display unit 63 corresponds to the frequency display unit 331 in FIG. 2 and displays the resonance frequency value detected by the frequency detection unit 43.
[0045]
In the capacitor testing apparatus 1 according to the present embodiment, as a method for tracking a resonance state in a resonance circuit including a capacitor 11 connected as a test target and a resonance built-in coil 12, a test applied by the applied power generation unit 2 to the resonance circuit. A method of controlling the frequency of power is used.
[0046]
In order to realize such a tracking method, the resonance control unit 3 includes an applied waveform generation unit 31 and an applied waveform correction unit 32. The applied waveform generator 31 generates a high-frequency AC signal at a desired frequency necessary for the capacitor test. The generated AC signal is output to the applied power generation unit 2 and is used to generate test power at a desired frequency in the applied power generation unit 2.
[0047]
The applied waveform correction unit 32 controls the frequency of the test power applied to the resonance circuit so that the resonance state in the resonance circuit is sufficiently maintained with respect to the applied power generation unit 2. 31.
[0048]
Specifically, as shown in FIG. 3, the applied waveform correction unit 32 includes an AC signal output from the applied waveform generation unit 31 to the applied power generation unit 2, and a resonance circuit including the capacitor 11 and the coil 12. The output resonance signal is input. The applied waveform correction unit 32 compares the phase of the AC signal and the resonance signal, and applies the applied waveform generation unit 31 and the applied power generation unit 2 so that the resonance frequency matches the frequency of the AC signal necessary for the test. To perform feedback control.
[0049]
In this way, by tracking the resonance state using the resonance frequency, it is possible to apply circuit elements and techniques used in the high-frequency circuit, and the circuit configuration of the apparatus is simplified. For example, a PLL (Phase Locked Loop) circuit can be used as the applied waveform correction unit 32 that performs frequency feedback control.
[0050]
As another tracking method for the resonance state, the voltage of the test power applied by the applied power generation unit 2 can be controlled by the resonance control unit 3. When the phase of the AC signal (test power) and the resonance signal shift, the voltage (power amplitude) of the high-frequency power applied to the capacitor 11 varies due to resonance as the resonance frequency changes. On the other hand, if the frequency deviation is within a certain range, the frequency deviation can be compensated by voltage control, and the application of high-voltage high-frequency power to the capacitor 11 can be maintained.
[0051]
Further, in the capacitor test apparatus 1 shown in FIG. 3, the resonance control unit 3 is configured to control the applied power generation unit 2, but as shown in FIG. It is also possible to track the resonance state by controlling.
[0052]
However, in the configuration in which the coil 12 is made variable, the apparatus may be increased in size or the inductance variable range may be narrow. Therefore, in terms of the size of the apparatus and the tracking range of the resonance state, it is preferable that the resonance control unit 3 controls the frequency or voltage of the test power applied by the applied power generation unit 2 to the resonance circuit. These resonance tracking methods may be selected and applied according to the specific configuration of each test apparatus, the required tracking range, and the like.
[0053]
A capacitor testing method using the capacitor testing apparatus 1 shown in FIGS. 1 to 3 will be described. The test mode and timer mode used in the specific examples shown below are selected by, for example, the test mode changeover switch 333 and the timer mode changeover switch 316 on the front panel having the configuration shown in FIG. , It is preset as the specification of the test apparatus. In the following, these modes are selectable as test conditions.
[0054]
FIG. 4 is a flowchart showing a first example of the capacitor testing method. The present embodiment shows the operation and operation contents of the capacitor testing apparatus 1 in the test mode = automatic resonance frequency detection tracking mode and the timer mode = timer mode. The automatic detection tracking mode is a mode in which a necessary sine wave voltage / current is applied to the capacitor 11 by automatically tracking the resonance frequency in the series resonance circuit including the capacitor 11 and the coil 12. . The timer mode is a mode in which a capacitor test is performed with a preset timer setting time.
[0055]
First, a capacitor 11 to be tested is prepared and a capacitor test is prepared (step S101). The resonance frequency f in the series resonance circuit including the capacitor 11 and the built-in coil 12 is expressed by the following equation from the capacitance C of the capacitor 11 and the inductance L of the coil 12.
f = 1 / 2π√ (LC) [Hz]
It is calculated by.
[0056]
It is confirmed whether or not the obtained resonance frequency f is within a testable frequency range in the test apparatus 1. If it is out of range, the coil switching tap is changed (see FIG. 2), or a plurality of capacitors are connected in series or in parallel so that the test can be performed within the frequency range.
[0057]
Also, the current flowing to the capacitor 11 is confirmed. The reactance of the capacitor is obtained by the following equation.
[0058]
Zc = 1 / ωC = 1 / 2πfC [Ω]
When the applied voltage of the capacitor 11 is Vc with respect to this Zc, the conduction current Ic is
Ic = Vc / Zc [A]
It is calculated by. Since each coil 12 has an allowable maximum capacity current, it is confirmed that the obtained energization current Ic is less than that. If the allowable value is exceeded, the test is performed with the applied voltage lowered.
[0059]
Open the cover of the coil operation unit 120 and set the inductance of the coil 12 by the short bar 122, open the cover of the capacitor installation unit 110, set the capacitor 11 to be tested to the test terminals 11a and 11b, and close the cover. Then turn on the device.
[0060]
Next, test conditions for the capacitor 11 are set (S102). An automatic detection tracking mode (automatic resonance) is set as a test mode by the test mode changeover switch 333. Further, the timer mode is set as the timer mode by the timer mode changeover switch 316, and necessary conditions such as the timer setting time are set by the timer operation unit 314.
[0061]
Further, in order to automatically detect and track the resonance frequency, the applied waveform correction unit 32 requires an applied voltage that is greater than a predetermined value, so that the voltage value in the voltage setting volume 323 satisfies such a condition. Set.
[0062]
When the setting of each condition is completed, the capacitor test is started (S103). When the test is started, first, the resonance frequency is automatically detected (S104). The applied waveform generator 31 outputs a low-level AC signal to the applied power generator 2 to apply AC power to the resonance circuit. Then, while automatically changing the frequency of the AC signal (AC power), the resonance frequency is detected by utilizing a sudden voltage increase due to resonance, and the detected resonance frequency is locked in. The locked resonance frequency in the resonance circuit is displayed on the frequency display unit 63 (frequency display unit 331 in FIG. 2) via the frequency detection unit 43.
[0063]
At this time, when the frequency of the AC power applied by the applied power generation unit 2 and the resonance frequency in the series resonance circuit including the capacitor 11 and the coil 12 match, a predetermined voltage having a sinusoidal waveform is applied to the capacitor 11 of the resonance circuit. • Current is applied. After the resonance frequency is locked, the resonance frequency is automatically tracked by the applied waveform correction unit 32 of the resonance control unit 3 so as to cancel the deviation of the frequency value.
[0064]
Subsequently, a test power is applied to the resonance circuit while automatically tracking the resonance frequency, and a necessary test at a high frequency and a high voltage is performed on the capacitor 11 to be tested (S105). First, the voltage setting volume 323 is operated to set a desired applied voltage value as test power. Then, the test power at the set applied voltage value is applied to the capacitor 11 by the amplification function of the applied power generation unit 2. By using series resonance while tracking the resonance frequency, a voltage larger than the AC input can be reliably applied to the capacitor 11.
[0065]
Further, during the test time of the capacitor performed by applying the test power from the applied power generation unit 2, the display unit is connected via the voltage detection unit 41, the current detection unit 42, and the frequency detection unit 43 of the detection unit 4. The detected applied voltage value, energized current value, and resonant frequency value are displayed on the voltage display unit 61, current display unit 62, and frequency display unit 63, respectively. Various capacitor tests such as a characteristic test, a reliability test, and a destructive test are performed by measuring the value of each display and the change with time. When the necessary test is completed, the capacitor test is stopped (S106).
[0066]
FIG. 5 is a timing chart showing an operation example of the capacitor testing apparatus 1 in the capacitor testing method shown in FIG. Each chart in FIG. 5 includes a start signal A for instructing start of a capacitor test, a stop signal B for instructing stop of the capacitor test, and an applied signal C for instructing application of test power by the applied power generation unit 2 from above. 2 shows a correction signal D for instructing control of the test power by the resonance control unit 3 and a test power E applied to the resonance circuit.
[0067]
First, in response to an instruction from the start signal A, preparation for enabling the internal configuration included in the apparatus is performed at time (operation period) T11. Next, when the applied signal C is turned ON, first, at time T12, the resonance frequency is automatically detected and the frequency is locked in the resonance circuit.
[0068]
Subsequently, when the resonance frequency is locked, the correction signal D is turned ON and frequency tracking is started, and test power is applied to the capacitor 11 over time T13 to perform a necessary capacitor test. Note that in the application of the test power, a soft start for preventing a rapid power application to the capacitor 11 is performed at time T14 immediately after the start of the application.
[0069]
When the timer setting time T10 set in the timer mode has elapsed from the start signal A, the capacitor test is terminated.
[0070]
In this automatic resonance frequency detection tracking mode, the resonance state in the series resonance circuit composed of the capacitor 11 and the coil 12 can be accurately maintained, and the capacitor test can be performed reliably.
[0071]
FIG. 6 is a flowchart showing a second example of the capacitor testing method. The present embodiment shows the operation and operation contents of the capacitor testing apparatus 1 in the test mode = manual frequency setting resonance mode and the timer mode = cycle mode. The manually set resonance mode is a mode in which the frequency of the test power applied to the series resonance circuit including the capacitor 11 and the coil 12 is manually varied. In addition, the cycle mode is a mode in which the capacitor test is repeated by a preset number of counters.
[0072]
First, the capacitor 11 to be tested is prepared, and the capacitor test is prepared in the same manner as the capacitor test method shown in FIG. 4 (step S201). When preparation is complete, turn on the device.
[0073]
Next, test conditions for the capacitor 11 are set (S202). The test mode changeover switch 333 sets a manually set resonance mode (manual resonance) as a test mode. In addition, the cycle mode is set as the timer mode by the timer mode change-over switch 316, and necessary conditions such as the cycle time and the counter setting number are set by the timer operation unit 314 and the counter operation unit 315.
[0074]
When the setting of each condition is completed, the capacitor test is started (S203). When the test is started, first, the resonance frequency is manually set (S204). The applied waveform generator 31 outputs a low-level AC signal to the applied power generator 2 to apply AC power to the resonance circuit. Then, while manually changing the frequency by operating the frequency setting volume 332, the resonance frequency is set by using a sudden voltage increase due to resonance, and locked in at the set resonance frequency. The locked resonance frequency in the resonance circuit is displayed on the frequency display unit 63 (frequency display unit 331 in FIG. 2) via the frequency detection unit 43.
[0075]
At this time, when the frequency of the AC power applied by the applied power generation unit 2 and the resonance frequency in the series resonance circuit including the capacitor 11 and the coil 12 match, a predetermined voltage having a sinusoidal waveform is applied to the capacitor 11 of the resonance circuit. • Current is applied. After the resonance frequency is locked, the resonance control unit 3 automatically tracks the voltage in the resonance state so as to cancel the voltage value deviation.
[0076]
Subsequently, a test power is applied to the resonance circuit while automatically tracking the resonance voltage, and a necessary test at a high frequency and a high voltage is performed on the capacitor 11 to be tested (S205). First, the voltage setting volume 323 is operated to set a desired applied voltage value as test power. Then, the test power at the set applied voltage value is applied to the capacitor 11 by the amplification function of the applied power generation unit 2. By using series resonance while tracking the resonance voltage, a voltage larger than the AC input can be reliably applied to the capacitor 11.
[0077]
Further, during the test time of the capacitor performed by applying the test power from the applied power generation unit 2, the display unit is connected via the voltage detection unit 41, the current detection unit 42, and the frequency detection unit 43 of the detection unit 4. The detected applied voltage value, energized current value, and resonant frequency value are displayed on the voltage display unit 61, current display unit 62, and frequency display unit 63, respectively. Various capacitor tests such as a characteristic test, a reliability test, and a destructive test are performed by measuring the value of each display and the change with time. When the necessary test is completed, the capacitor test is stopped (S206).
[0078]
FIG. 7 is a timing chart showing an operation example of the capacitor testing apparatus 1 in the capacitor testing method shown in FIG. Each chart in FIG. 7 includes a start signal A for instructing start of a capacitor test, a stop signal B for instructing stop of the capacitor test, and an applied signal C for instructing application of test power by the applied power generation unit 2. 2 shows a correction signal D for instructing control of the test power by the resonance control unit 3 and a test power E applied to the resonance circuit.
[0079]
First, in response to an instruction from the start signal A, preparation for enabling the internal configuration included in the apparatus is performed at time (operation period) T21. Next, when the applied signal C is turned ON, first, at time T22, the resonance frequency is manually set and the frequency is locked in the resonance circuit.
[0080]
Subsequently, when the resonance frequency is locked, the correction signal D is turned ON to start voltage tracking, and test power is applied to the capacitor 11 over time T20, and a necessary capacitor test is performed.
[0081]
Specifically, in the capacitor test in the cycle mode, the correction signal D is turned on to apply the test power and the voltage tracking is performed T23, and the correction signal D is turned off and the test power application is suspended. The pause time T24 to be performed is repeated for the set counter setting number of times. Accordingly, the test time T20 is a time obtained by repeating one cycle time T25 including the application time T23 and the rest time T24 by the counter set number of times. In each of the application times T23 that are repeatedly performed, a soft start for preventing a rapid power application to the capacitor 11 is performed at a time T26 immediately after the start of the application.
[0082]
When the cycle time set in the cycle mode and the time T20 based on the counter setting number have elapsed from the first correction signal D, the capacitor test is terminated.
[0083]
In this manual frequency setting resonance mode, when a capacitor whose resonance frequency is known in advance is used as a test object, the time for automatically detecting the resonance frequency can be shortened, and the capacitor test can be performed efficiently. In particular, in the cycle mode in which the test power is applied a plurality of times, it is preferable to use such manual setting in order to omit the time for automatically detecting the resonance frequency for each cycle.
[0084]
The configuration of the capacitor testing apparatus 1 shown in FIGS. 1 to 3 will be described more specifically. In the capacitor testing apparatus 1 according to the third and fourth embodiments shown below, similarly to the second embodiment shown in FIG. 3, the resonance composed of the capacitor 11 connected as a test object and the resonance built-in coil 12. As a method for tracking the resonance state in the circuit, a method is used in which the applied power generation unit 2 controls the frequency of the test power applied to the resonance circuit. However, the same configuration is possible even when a method for controlling the voltage of the test power is used.
[0085]
FIG. 8 is a block diagram schematically showing the configuration of the third embodiment of the capacitor testing apparatus. The configuration of the capacitor testing apparatus 1 of the present embodiment is the same as that of the first and second embodiments with respect to the coil 12, the detection unit 4, and the setting unit 5.
[0086]
The applied power generation unit 2 in the present embodiment is configured to include a DC variable power source 21 and an inverter 22. The DC variable power supply 21 is supplied with predetermined power such as normal AC power from a commercial power supply.
[0087]
The DC variable power source 21 converts the AC input of the power source to generate DC power, and supplies the DC power to the inverter 22. Further, the inverter 22 generates test power having a sufficient voltage at a high frequency from the DC power supplied from the DC variable power source 21 and applies the test power to the resonance circuit including the capacitor 11 and the coil 12.
[0088]
On the other hand, the resonance control unit 3 includes an applied waveform generation unit 31 and an applied waveform correction unit 32 (see FIG. 3). In addition, the applied waveform generation unit 31 is provided with an inverter control unit 33 corresponding to the configuration of the applied power generation unit 2 described above. The inverter control unit 33 outputs an AC signal necessary for the capacitor test via the inverter 22.
[0089]
By using the inverter 22 to generate and apply test power by the applied power generation unit 2, it is possible to efficiently generate and apply test power from a commercial power source or the like to a resonance circuit for capacitor testing from a commercial power source or the like. .
[0090]
More specifically, the inverter 22 uses a DC input supplied from the DC variable power supply 21 as a power source, amplifies AC power of a frequency controlled by the inverter control unit 33, and applies it to the resonance circuit as test power. Preferably, it is comprised from the full bridge | bridging of FET. The power value of the test power generated by the inverter 22 is controlled by changing the power supply value from the DC variable power source 21 to the inverter 22. These are set by, for example, setting contents input from the setting unit 5.
[0091]
Thus, according to the configuration in which the inverter 22 is applied as a power source for supplying high-frequency test power to a capacitor test circuit in which the load is an LC resonance circuit, the inverter 22 has zero current switching. Loss such as switching loss at 22 is kept small, so that test power can be generated and applied with high efficiency.
[0092]
However, in the inverter 22, it is necessary to provide a dead time in order to prevent the switching elements that operate alternately from turning on at the same time, and there is an upper limit to the frequency of the test power that can be generated. The frequency range of the test power (a frequency range that can be tested in the test apparatus 1) in the configuration using the inverter 22 in the applied power generation unit 2 is, for example, about 10 to 130 kHz.
[0093]
FIG. 9 is a block diagram schematically showing the configuration of the fourth embodiment of the capacitor testing apparatus. The configuration of the capacitor testing apparatus 1 of the present embodiment is the same as that of the first and second embodiments with respect to the coil 12, the detection unit 4, and the setting unit 5.
[0094]
The applied power generation unit 2 in the present embodiment is configured to include a broadband power amplifier 23. The broadband power amplifier 23 is supplied with predetermined power such as normal AC power from a commercial power source. The broadband power amplifier 23 amplifies AC power having a frequency set within an amplification frequency band that can be amplified, generates test power having a sufficient voltage at a high frequency, and applies the test power to a resonance circuit including the capacitor 11 and the coil 12. .
[0095]
On the other hand, the resonance control unit 3 includes an applied waveform generation unit 31 and an applied waveform correction unit 32 (see FIG. 3). The applied waveform generation unit 31 is provided with a sine wave generator 34 corresponding to the configuration of the applied power generation unit 2 described above. The sine wave generator 34 outputs an AC signal necessary for the capacitor test via the broadband power amplifier 23.
[0096]
By using the wideband power amplifier (power amplifier) 23 for the generation and application of the test power by the applied power generator 2, it is possible to generate and apply a sufficiently high frequency test power to the resonance circuit of the capacitor test. .
[0097]
More specifically, the broadband power amplifier 23 uses an AC input as a power source, amplifies AC power having a frequency controlled by the sine wave generator 34, and applies the amplified AC power to the resonance circuit as test power. The power value of the test power generated by the broadband power amplifier 23 is controlled by changing the amplification factor in the power amplifier 23 and the like. These are set by, for example, setting contents input from the setting unit 5.
[0098]
Thus, according to the configuration in which the broadband power amplifier 23 is applied as a power source for supplying high-frequency test power to the capacitor test circuit, the frequency of the test power applied to the resonance circuit including the capacitor 11 and the coil 12 The upper limit of can be increased. The frequency range of the test power in the configuration using the broadband power amplifier 23 in the applied power generation unit 2 (the testable frequency range in the test apparatus 1) is, for example, about 10 to 500 kHz. The upper limit of the frequency is also high.
[0099]
However, in the broadband power amplifier 23, the efficiency with respect to the AC power input as the power source is lower than that of the inverter 22, and the upper limit of the voltage of the test power that can be generated is slightly lower. The upper limit of such voltage is, for example, that the upper limit voltage value in the broadband power amplifier 23 is about 4000 V, compared to the upper limit voltage value in the inverter 22 of 6000 V.
[0100]
FIG. 10 is a block diagram schematically showing the configuration of the fifth embodiment of the capacitor testing apparatus. The configuration of the capacitor testing apparatus 1 of the present embodiment is the same as that of the first embodiment with respect to the applied power generation unit 2, the resonance control unit 3, and the setting unit 5.
[0101]
In the capacitor testing apparatus 1 according to the present embodiment, a coil 12 connected in series to a capacitor 11 and constituting a resonance circuit is installed as a coil unit 13 configured to be able to replace the coil 12 by being attached to and detached from the apparatus.
[0102]
Specifically, in the present embodiment, as described with reference to the example of FIG. 2, the coil 12 used in the resonance circuit for the capacitor test is provided with several taps having a low inductance value and one coil unit is provided for several taps. 13 is a plug-in system that can be manually switched. As a result, the inductance of the coil can be changed between the taps, while the coil determined to be used for the test can be a fixed inductance.
[0103]
Further, the coil unit 13 is configured to be detachable from the test apparatus 1. As a result, the coil 12 used in the resonance circuit can be exchanged as necessary.
[0104]
In addition to the voltage detection unit 41, the current detection unit 42, and the frequency detection unit 43, the detection unit 4 is provided with a set detection unit 44 for the configuration using the coil unit 13. The set detection unit 44 detects a set state of the coil unit 13 including the coil 12 in the test apparatus 1.
[0105]
Information about the set state detected by the set detection unit 44 is input to the applied power generation unit 2. The applied power generation unit 2 prohibits application of test power to the resonance circuit including the capacitor 11 and the coil 12 when the set detection unit 44 detects a set state failure of the coil unit 13.
[0106]
A display unit 6 is installed corresponding to the detection unit 4. In the display unit 6 in the configuration example illustrated in FIG. 10, a set display unit 64 is provided in addition to the voltage display unit 61, the current display unit 62, and the frequency display unit 63. The set display unit 64 displays the set state of the coil unit 13 detected by the set detection unit 44. As such a set display unit 64, for example, a configuration in which an abnormal lamp is turned on when a defective set state is detected, such as an abnormal display lamp 313 in FIG. 2, can be used.
[0107]
In the capacitor test, test power can be applied to a resonant circuit consisting of a capacitor and a coil over a wider frequency range and voltage range in order to allow a wide range of characteristics to be tested for various capacitors. It is hoped to do. On the other hand, by setting the coil 12 for constituting the resonance circuit as described above as a replaceable (detachable) coil unit 13, the capacitor 11 to be tested is desired in a wide frequency range. It is possible to efficiently test the capacitor 11 by applying high-frequency high-frequency power at a frequency of.
[0108]
In addition, a set detection unit 44 is provided for the detachable coil unit 13, and when the set detection unit 44 detects a set state failure of the coil unit 13, application of test power to the resonance circuit by the applied power generation unit 2 Is prohibited, and an error lamp displays an error.
[0109]
If the short bar 122 is connected to the coil terminal 121 while the coil unit 13 is in a poorly set state, there is a risk that a spark is generated near the short bar 122 due to vibration or the like. On the other hand, by detecting the set state failure as described above and controlling the operation of the test apparatus 1, problems caused by the replacement of the coil unit 13 can be prevented, and the safety of the apparatus can be improved. it can.
[0110]
FIG. 11 is a perspective view showing the configuration of the coil unit and the like in the embodiment of the capacitor testing apparatus shown in FIG. A coil unit 13 shown in FIG. 11 incorporates a coil 12 made of an air-core coil and is detachable from the apparatus main body. A coil terminal 121 for switching the coil is provided on the front surface of the coil unit 13 (see FIG. 2). In such an air-core coil, the test range such as the frequency value and voltage value in the resonance state can be widened by changing the winding method and the specifications of the copper wire to be used.
[0111]
A micro switch 44 a is installed as a set detection unit 44 on the apparatus main body side with respect to the detachable coil unit 13. The micro switch 44a detects a good set state when the coil unit 13 attached to the apparatus main body pushes the button 44b.
[0112]
The capacitor test method when the coil 12 is the coil unit 13 is basically the same as the test method shown in FIG. 4 or FIG. 6, but the coil unit 13 and the coil 12 are set according to the resonance frequency. The difference is that the operation can be changed, and the operation differs depending on the set state of the coil unit 13 detected by the set detection unit 44.
[0113]
Referring to the flowchart of FIG. 4, first, in the capacitor test preparation stage (step S101), depending on the resonance frequency f or energization current Ic obtained for the capacitor 11 to be tested, as required. The coil 12 used for resonance can be changed by exchanging the coil unit 13.
[0114]
Further, when the preparation is completed and the apparatus is turned on, the set state of the coil unit 13 is detected by the set detection unit 44. When the set state is good (normal) is detected, the capacitor test is sequentially performed in steps S102 to S106 shown in FIG.
[0115]
On the other hand, when a set state failure (abnormality) is detected, information on the set state failure is output to the applied power generation unit 2 and the set display unit 64. As a result, the applied power generation unit 2 is in a state where application of the test power to the resonance circuit is prohibited. Moreover, the set display part 64 lights LED of the abnormality display lamp 313 which shows a set state defect.
[0116]
At this time, the operator confirms the set state failure by lighting the abnormality display lamp 313, and resets the coil unit 13 normally. As a result, when the set detection unit 44 detects that the set state is good (normal), the capacitor test in steps S102 to S106 shown in FIG. 4 is subsequently performed.
[0117]
Even when the capacitor test is being performed, if the set detection unit 44 detects a set state failure, the test is forcibly terminated, and application of the test power to the resonance circuit is prohibited. At the same time, the LED of the abnormality display lamp 313 indicating a defective set state is turned on.
[0118]
The capacitor testing apparatus according to the present invention is not limited to the above-described embodiments and examples, and various modifications can be made. For example, the configuration of the detection unit 4, the setting unit 5, the display unit 6, and the like is not limited to the configuration described above, and various configurations may be used depending on the method of determining the result of the capacitor test.
[0119]
As for the resonance state tracking method in the resonance circuit including the capacitor and the coil, in the example of the test method using the timer mode and the cycle mode described above, the frequency tracking is performed in the timer mode and the voltage tracking is performed in the cycle mode. However, for example, different configurations such as frequency tracking in the cycle mode may be used, or frequency and voltage tracking, or tracking by making the coil variable may be combined. As for the timer mode, a manual mode for manually instructing to stop the test without using the timer may be used.
[0120]
【The invention's effect】
As described in detail above, the capacitor testing apparatus according to the present invention has the following effects. That is, when testing a capacitor using resonance, the test condition for the test power applied to the resonance circuit composed of the capacitor and the coil is not made constant during the test time, and the resonance state is automatically tracked by the resonance control means. According to the capacitor testing apparatus, even when the resonance condition changes due to a change in the capacitance of the capacitor during the test time, the resonance state is well maintained.
[0121]
At this time, for the capacitor to be tested, the high frequency power applied to the capacitor is kept at a sufficiently high voltage throughout the test time, and therefore, the desired frequency for the capacitor to be tested is The necessary test can be reliably performed by applying the test power at a sufficiently high voltage.
[0122]
In addition, by setting the coil for configuring the resonant circuit as a replaceable (detachable) coil unit, high voltage high frequency power is applied to the capacitor under test at a desired frequency in a wide frequency range. Thus, the capacitor can be efficiently tested.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a first embodiment of a capacitor testing apparatus.
FIG. 2 is a front view showing a configuration of an embodiment of the capacitor testing apparatus shown in FIG. 1;
FIG. 3 is a block diagram showing a configuration of a second embodiment of the capacitor testing apparatus.
FIG. 4 is a flowchart showing a first example of a capacitor testing method.
5 is a timing chart showing the operation of the test apparatus in the capacitor testing method shown in FIG.
FIG. 6 is a flowchart showing a second example of a capacitor testing method.
7 is a timing chart showing the operation of the test apparatus in the capacitor testing method shown in FIG. 6. FIG.
FIG. 8 is a block diagram showing a configuration of a third embodiment of a capacitor testing apparatus.
FIG. 9 is a block diagram showing a configuration of a fourth embodiment of a capacitor testing apparatus.
FIG. 10 is a block diagram showing a configuration of a fifth embodiment of a capacitor testing apparatus.
11 is a perspective view showing a configuration of an embodiment of the capacitor testing apparatus shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Capacitor test apparatus, 11 ... Capacitor, 11a, 11b ... Test terminal, 12 ... Coil, 13 ... Coil unit, 2 ... Applied power generation part, 21 ... DC variable power supply, 22 ... Inverter, 23 ... Broadband power amplifier, 3 Resonance control unit 31 Application waveform generation unit 32 Application waveform correction unit 33 Inverter control unit 34 Sine wave generator 4 Detection unit 41 Voltage detection unit 42 Current detection unit 43 ... frequency detection unit, 44 ... set detection unit, 5 ... setting unit, 6 ... display unit, 61 ... voltage display unit, 62 ... current display unit, 63 ... frequency display unit, 64 ... set display unit,
DESCRIPTION OF SYMBOLS 100 ... Resonant circuit panel, 110 ... Capacitor installation part, 120 ... Coil operation part 121 ... Coil terminal, 122 ... Short bar, 200 ... Power panel, 300 ... Control panel, 301 ... Power switch, 310 ... Main operation part, 320 ... Power operation unit, 330... Frequency operation unit.

Claims (3)

A coil unit that is connected in series to a capacitor to be tested and constitutes a resonance circuit, and that is configured so that the coil can be exchanged by attaching and detaching the coil unit;
Application power generation means for applying a test power of a predetermined frequency to the resonance circuit ,
The coil unit has a built-in the coil, the coil operating portion provided on the front panel of the device front, a capacitor testing apparatus characterized that you have been configured to be capable of detachable from the apparatus main body. A set detecting means for detecting a set state of the coil unit;
The applied power generating means, the set when the detecting means detects the set state failure, the capacitor testing apparatus of claim 1, wherein the prohibiting application of the test power to the resonant circuit. The coil built in the coil unit includes a plurality of taps having a low inductance value, and is configured as a plug-in system that can be manually switched with a plurality of taps as one unit.
  3. The capacitor testing apparatus according to claim 1, wherein a coil terminal of a coil switching tap for switching the inductance of the coil is provided on the front surface of the coil unit.

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