JP2020173139A - Device and method for diagnosing degradation - Google Patents

Abstract

To provide a device and a method for diagnosing a degradation which can easily diagnose a degradation in a signal conveying device while the device is being equipped in a substrate as a substrate assembly.SOLUTION: A degradation diagnosing device 15 includes an input-side circuit unit 51 and an output-side circuit unit 52. The input-side circuit unit 51 includes a first terminal pair, a first power source 56, an adjustment circuit 57, and a current meter 58. The first power source 56 is connected to an input terminal pair of a light emitting unit 25 of a photocoupler 11 by the first terminal pair. The adjustment circuit 57 increases or reduces a first current flowing in the light emitting unit 25 from the first power source 56. The current meter 58 measures the first current. The output-side circuit unit 52 has a second terminal pair and an output-side measuring unit, and the output-side measuring unit measures the output voltage of a light reception unit 26 by the second terminal pair.SELECTED DRAWING: Figure 3

Description

The present invention relates to a deterioration diagnostic device and a method for diagnosing deterioration of a signal transmission device.

In manufacturing equipment for various products, such as film manufacturing equipment (solution film forming equipment) that manufactures long films by the solution film forming method, multiple transmission devices or signal input / output are used to control each part that constitutes the equipment. Board assemblies such as equipment are used. For example, in the case of the above film manufacturing equipment, a casting part that forms a casting film from a dope (polymer solution), a drying part that dries the film formed by peeling the casting film from a support, and a long film. There are a stretched part for stretching the film, a winding part for winding the film in a roll shape, and the like, and a large number of substrate assemblies are used for the control part for controlling each of these parts.

Generally, a plurality of signal transmitters are mounted on the board assembly. For example, a large number of signal transmission devices of 10 or more are mounted on each of the plurality of substrate assemblies used in the above film manufacturing facility. As described above, there are many cases where a large number of signal transmission devices are used in one manufacturing facility.

As a signal transmission device, for example, there is a photocoupler. As is well known, a photocoupler includes a light emitting unit and a light receiving unit that receives light from the light emitting unit. Signal transduction devices such as optocouplers deteriorate like other electronic devices. If the function of transmitting signals does not work due to deterioration, the manufacturing may be hindered, and in some cases, the operation of the manufacturing equipment may be stopped. Therefore, it is usual to replace the signal transduction device with a new one before such a situation occurs. Therefore, the larger the number used, the more time and effort it takes to replace it.

As a technique for detecting deterioration of a photocoupler, Patent Document 1 describes a self-diagnosis circuit including a detection circuit, an energization circuit, and a control determination circuit. The detection circuit detects on and off of the external contact by the output voltage of the light receiving part of the photocoupler and outputs it. When the photocoupler is deteriorated, the energizing circuit passes a diagnostic current to the light emitting part of the photocoupler through a resistor that limits the current so that the output of the light receiving part of the photocoupler does not reach the detection level of the external contact ON of the detection circuit. Shed. At the same time as the diagnostic current is passed, the control circuit reads the detection result of the detection circuit, and when this detection result is not in the detection state of the external contact ON, it determines that the photocoupler has deteriorated and outputs it.

Further, in Patent Document 2, a first photocoupler to be detected for deterioration, a controller for controlling the drive of the first photocoupler, an output detection circuit, and a value detected by the output detection circuit are transmitted to the controller. A photocoupler device including a second photocoupler is described. The output detection circuit generates and outputs a detection value which is a value corresponding to the potential of the output signal of the first photocoupler. The controller performs a determination process for determining whether or not the first photocoupler is in an output deterioration state based on the above-mentioned detected value when the first photocoupler is driven, and this determination result is k times (k ≧). Every time the output deteriorates up to 2), an adjustment process is performed to increase the drive current of the first photocoupler.

Patent Document 3 describes a photosensor including a light emitting diode and a phototransistor, a power supply, a variable supply power supply that changes the voltage of the power supply, and a switch that switches between the power supply and the variable power supply. .. Deterioration of this photo sensor is detected by lowering the supply power supply on the light emitting side by the power supply variable unit and comparing the operating limit voltage with the initial stage.

JP-A-2002-237228 Japanese Unexamined Patent Publication No. 2011-199201 Jikkai Sho 63-159856

However, in Patent Documents 1 to 3, a diagnostic circuit for diagnosing deterioration of each signal transmission device is provided. Therefore, it is necessary to incorporate the board assembly when mounting on a board, and the number of signal transmission devices mounted on one board is limited. Then, in a board assembly in which a large number of signal transmission devices are densely mounted on the board, deterioration diagnosis of individual signal transmission devices cannot be performed.

Therefore, an object of the present invention is to provide a deterioration diagnosis device and a deterioration diagnosis method that can easily diagnose deterioration of a signal transmission device while being mounted on a board as a board assembly.

In order to achieve the above object, the deterioration diagnostic apparatus of the present invention includes an input side circuit unit and an output side circuit unit. The input-side circuit unit includes a first terminal pair, a first power supply, an adjustment circuit, and an input-side measurement unit. The first terminal pair is connected to the input terminal pair of the light emitting unit of the signal transmission device including the light emitting unit and the light receiving unit that receives the light from the light emitting unit. The first power supply is connected to the input terminal pair via the first terminal pair. The adjustment circuit increases or decreases the first current flowing from the first power source to the light emitting unit. The input side measuring unit measures the first current. The output side circuit unit has a second terminal pair and an output side measurement unit. The second terminal pair is connected to the output terminal pair of the light receiving unit. The output side measuring unit measures the output voltage of the light receiving unit or the second current flowing through the light receiving unit via the second terminal pair.

The signal transduction device is preferably a photocoupler.

The adjustment circuit preferably has a variable resistor connected in series with the first power supply.

The output side measuring unit preferably has a resistor, a second power source, and a voltmeter. The resistor forms a series circuit with the light receiving part. The second power supply is connected to both ends of the series circuit. The voltmeter measures the voltage between the output terminals of the light receiving unit.

The light emitting unit and the light receiving unit are provided on one circuit chip with the input terminal pair and the output terminal pair protruding, and the circuit chip is provided on the board, and the first terminal pair and the second terminal pair are provided. Is preferably connected to the input terminal pair and the output terminal pair of the signal transmission device on the substrate.

The first terminal pair and the second terminal pair are preferably provided on a connecting member that connects the circuit chip to the circuit chip by gripping or fitting the circuit chip.

It is preferable that the output side circuit unit further has a voltage supply terminal for supplying a drive voltage to the light receiving unit.

The voltage supply terminal is preferably connected to the light receiving portion of the signal transmission device on the substrate.

The deterioration diagnosis method of the signal transmission device of the present invention is a deterioration diagnosis method of a signal transmission device in which the diagnosis transmission device includes a light emitting unit and a light receiving unit that receives light from the light emitting unit, and includes a connection step, a specific step, and It has a diagnostic step. In the connection step, the first terminal pair of the deterioration diagnosis device is connected to the input terminal pair, and the second terminal pair is connected to the output terminal pair. In the specific step, after the connection step, the first current is increased or decreased by the adjustment circuit, and the value of the first current when the output voltage or the second current changes is specified by the output side measuring unit. In the diagnostic process, the first current specified in the specific process is compared with the preset reference value for deterioration, and if it is equal to or more than the reference value, it is determined that the deterioration signal transmission device is deteriorated, and the value is less than the reference value. If it is, it is judged that the deterioration has not occurred.

According to the present invention, deterioration of a signal transmission device can be easily diagnosed while being mounted on a board as a board assembly.

It is explanatory drawing of the signal transmission device, (A) is a schematic plan view, (B) is a schematic side view. It is a block diagram of a signal transmission device. It is a block diagram of the deterioration diagnosis apparatus. It is explanatory drawing of a clip. It is a graph which shows the relationship between the 1st current and an output voltage for explaining the method of deterioration diagnosis.

The substrate assembly 10 shown in FIG. 1 is an example of a substrate assembly including a plurality of photocouplers 11 which are objects for diagnosis of deterioration. The substrate assembly 10 of this example is provided in a control unit that controls each part of a film manufacturing facility (solution film forming facility) that manufactures a film by a solution film forming method. The substrate assembly 10 includes a substrate 12 and a plurality of photocouplers 11.

A reference clock (not shown), a data clock (not shown), an end clock (not shown), and the like are arranged in the substrate assembly 10, and a plurality of photocouplers 11 are provided for each of these. Therefore, there are many photocouplers 11 mounted on one substrate 12, but only three of them are drawn in FIG. 1A. The photocoupler 11 is electrically connected to a conductive member formed on the substrate 12. In FIG. 1, the above conductive member is not shown in order to avoid complication of the drawing.

The photocoupler 11 is an example of a signal transmission device including a light emitting unit and a light receiving unit that receives light from the light emitting unit, and deterioration is diagnosed using a deterioration diagnosis device 15 (see FIG. 3) described later. The object for which deterioration is diagnosed by the deterioration diagnosis device 15 is not limited to the photocoupler 11 as long as it is a signal transmission device including a light emitting unit and a light receiving unit as described above. Other signal transduction devices include, for example, photo interrupters, photoelectric switches, optical pulse generators, and the like.

The photocoupler 11 converts the input electric signal into light by the light emitting unit, and returns the light to the electric signal again by the light receiving unit, thereby transmitting the signal in an electrically insulated state. The photocoupler 11 is provided on the circuit chip 20 as a package member, and is connected to the input terminals 21a and 21b of the light emitting unit, the output terminals 22a and 22b of the light receiving unit, and the power supply voltage (Vcc) from the circuit chip 20. The power supply connection terminal 22c for this purpose is projected. These input terminals 21a and 21b, the output terminals 22a and 22b, and the power supply connection terminal 22c are electrically connected to the above-mentioned conductive member of the substrate 12.

As shown in FIG. 2, the photocoupler 11 of this example includes a light emitting unit 25 on the input side and a light receiving unit 26 on the output side. The light emitting unit 25 is composed of a light emitting element, and specifically, a light emitting diode 31 and input terminals 21a and 21b which are a pair of input terminals connected to an internal circuit (board circuit) 39A of the board assembly 10 are provided. Have. The photocoupler 11 is used with the light emitting diode 31 connected to the positive (+) side of the power supply with the input terminal 21a as the anode and the negative (-) side of the power supply with the input terminal 21b as the cathode. To. The light emitting unit is not limited to this example, and for example, the light emitting unit in the above-mentioned photoelectric switch may be a laser.

In this example, the light receiving unit 26 includes a photodiode 35, an amplifier 36, a transistor 37, an output terminal pair (output terminals 22a, 22b) connected to the internal circuit (board circuit) 39B of the board assembly 10, and a power supply connection. It is provided with a terminal 22c. However, the light receiving unit 26 is not limited to this example, and may be composed of a light receiving element such as a phototransistor. The photodiode 35 is connected between the input terminals of the amplifier 36, and the output of the amplifier 36 is connected to the base of the transistor 37. The power supply terminal of the amplifier 36 is connected to a power supply (not shown) via the power supply connection terminal 22c, and a voltage is supplied to the amplifier 36. In the transistor 37, the current (emitter current) increases or decreases according to the current (base current) from the amplifier 36.

The photocoupler 11 may be a commercially available product. The photocoupler 11 of this example is also a commercially available product. The above-mentioned reference clock and data clock are the photocoupler PC410L0NIP manufactured by Sharp Corporation and the photocoupler PS9117A manufactured by Renesas Electronics Corporation, and the end signal is Avago. The photocoupler HCPL-M456 manufactured by Technology is used.

The deterioration diagnosis device 50 shown in FIG. 3 is an example of the present invention, and is for diagnosing deterioration of the photocoupler 11. The deterioration diagnosis device 50 includes an input side circuit unit 51 connected to the light emitting unit 25 of the photocoupler 11 and an output side circuit unit 52 connected to the light receiving unit 26. The input-side circuit unit 51 includes first terminal pairs 55a and 55b, a first power supply 56, an adjustment circuit 57, and an ammeter 58 as an input-side measurement unit. In the following description, when one 55a and the other 55b of the first terminal pair are not distinguished, it is described as the first terminal pair 55.

The first terminal pair 55 is connected to the above-mentioned input terminal pair. Reference numeral 55a is attached to the first terminal connected to the input terminal 21a, and reference numeral 55b is attached to the first terminal connected to the input terminal 21b. The first power supply 56 is connected to the input terminal pair via the first terminal pair 55. The positive (plus, +) poles of the first power supply 56 are connected to the input terminal 21a via the first terminal 55a, and the negative (minus,-) poles are connected to the input terminal 21b via the first terminal 55b.

The adjustment circuit 57 is for adjusting the amount of light emitted from the light emitting diode 31. The adjustment circuit 57 is provided between the first power supply 56 and the first terminal 55a, and has a fixed resistor 57a and a variable resistor 57b. The fixed resistor 57a suppresses the first current flowing through the light emitting unit 25 to a constant current value or less, and suppresses a sudden change in the first current when the first current is changed by the variable resistor 57b. The variable resistor 57b is provided on the side of the first terminal 55a with respect to the fixed resistor 75a, and changes the first current flowing through the light emitting unit 25. The adjusting circuit 57 increases or decreases the first current flowing from the first power source 56 to the light emitting unit 25, and the amount of light emitted from the light emitting diode 31 is adjusted by this increase or decrease. The adjusting circuit 57 is not limited to this example having the variable resistor 57b, but the variable resistor 57b is preferable in that it is small in size and the first current can be easily adjusted.

The voltage supplied from the first power source 56, the fixed resistor 57a, and the variable resistor 57b may be determined according to the specifications of the photocoupler 11, which is the object of deterioration diagnosis. The specifications when the photocoupler 11 is a commercially available product are described in the data sheet, and the specifications of the data sheet are also used in this example. In this example, the voltage of the first power supply 56 is set to 5V and the fixed resistor 57a is set to 470Ω based on the specifications described in the data sheet. Further, the variable resistor 57b has a variable range of 0Ω or more and 2kΩ or less. The fixed resistor 57a is obtained based on a graph (a graph at 25 ° C.) showing the relationship between the supply voltage of the data sheet and the primary side current value.

The ammeter 58 is provided between the first power supply 56 and the first terminal 55b, and measures the first current flowing to the light emitting unit 25.

The output side circuit unit 52 includes second terminal pairs 61a and 61b, a resistor (pull-up resistor) 64, a second power supply 65, and a voltmeter 66. In the following description, when one 61a and the other 61b of the second terminal pair are not distinguished, it is described as the second terminal pair 61.

The second terminal pair 61 is connected to the output terminal pair described above. Reference numeral 51a is attached to the second terminal connected to the output terminal 22a, and reference numeral 61b is attached to the second terminal connected to the output terminal 22b.

The resistor 64, the second power supply 65, and the voltmeter 66 form an output-side measuring unit that measures the output voltage of the light receiving unit 26 via the second terminal pair 61. The output-side measuring unit is not limited to this example, and may be replaced with a configuration in which the second current flowing through the light receiving unit 26 is measured via the second terminal pair 61. The resistor 64 forms a series circuit with the light receiving unit 26, and a second power supply 65 is connected to both ends of the series circuit. The second power supply 65 connects the anode to the resistor 64 side, that is, the second terminal 61a side, and the cathode to the second terminal side 61b side. By connecting the output unit side circuit unit in parallel with the input side circuit unit 51 from the first power supply 56, the first power supply 56 can be used as the second power supply without using the second power supply 65. ..

The voltmeter 66 is connected between the second terminal 61a and the resistor 64, and between the second terminal 61b and the cathode of the second power supply 65. As a result, the voltmeter 66 measures the voltage between the output terminals (22a, 22b) of the light receiving unit 26, that is, the voltage between the output terminal 22a and the output terminal 22b.

The output-side circuit unit 52 preferably further includes a voltage supply terminal 61c, which is also the case in this example. The voltage supply terminal 61c is for supplying a drive voltage to the amplifier 36 of the light receiving unit 26. In this example, the drive voltage is supplied from the second power source 65. Depending on the configuration of the light receiving unit, for example, when a light receiving element such as a phototransistor is used as the light receiving unit, the supply of voltage from the second power supply 65 may not be necessary, or the first power supply 56 may be used as described above. May be used as a second power source.

The voltage of the second power supply 65 and the resistor 64 are set based on the data sheet of the photocoupler 11. In this example, the voltage of the second power supply 65 is 5 V, and the resistance 64 is 10 kΩ.

The first terminal pair (first terminal 55a, 55b) and the second terminal pair (second terminal 61a, 61b) are preferably provided on the clip 67 as shown in FIG. When there is a voltage supply terminal 61c as in this example, it is preferable that the voltage supply terminal 61c is also provided on the clip 67, and this is also the case in this example. The clip 67 is an example of a connecting member that connects to the circuit chip 20 when the photocoupler 11 is provided on the circuit chip 20, and grips the circuit chip 20.

The clip 67 includes a first arm 68 and a second arm 70 that is swingably attached to the first arm 68 via a shaft rod 69. The clip 67 obtains continuity with the photocoupler 11 by sandwiching and fixing the circuit chip 20 between the first arm 68 and the second arm 70.

The first arm 68 is formed with a protruding portion 68a protruding toward the second arm 70 side at the peripheral edge portion. The second arm 70 is formed with a protruding portion 70a that protrudes toward the first arm 68 side. In the first arm 68 and the second arm 70, the protrusion 70a is arranged inside the protrusion 68a, and the tip portion 68t of the first arm 68 and the tip portion 70t of the second arm 70 face each other. .. A through hole through which the shaft rod 69 is inserted is formed in each of the protruding portion 68a and the protruding portion 70a, and the first arm 68 and the second arm 70 are formed by inserting the shaft rod 69 through these through holes. Is in a positioned state.

The first arm 68 and the second arm 70 are in a closed position where the tip portion 68t and the tip portion 70t are in a closed state as shown in FIG. 4 (A) and in an open state as shown in FIG. 4 (B). Change each other's posture with the open position. A spring (not shown) is provided between the first arm 68 and the second arm 70 to urge the postures of the first arm 68 and the second arm 70 to the closed position.

The first terminal 55a (see FIG. 3) and the first terminal 55b are provided on the first arm 68. The distance between the first terminal 55a and the first terminal 55b is set based on the distance between the input terminal 21a and the input terminal 21b. The second terminal 61a (see FIG. 3), the second terminal 61b, and the output supply terminal 61c are provided on the second arm 70. The distances between the output supply terminal 61c, the second terminal 61a (see FIG. 3), and the second terminal 61b are set based on the distances between the power supply connection terminal 22c, the output terminal 22a, and the output terminal 22b. As a result, when the photocoupler 11 is sandwiched between the tip portion 68t and the tip portion 70t as shown in FIG. 4B, the first terminal 55a and the input terminal 21a, the first terminal 55b and the input terminal 21b, and the output. The supply terminal 61c and the power supply connection terminal 22c, the second terminal 61a (see FIG. 3) and the output terminal 22a, and the second terminal 61b and the output terminal 22b are connected, respectively. In this way, the input side circuit unit 51 conducts to the light emitting unit 25, and the output side circuit unit 52 conducts to the light receiving unit 26.

The connecting member is not limited to the clip 67 as long as it is a member that conducts the input side circuit unit 51 to the light emitting unit 25 and the output side circuit unit 52 to the light receiving unit 26. For example, it may be a member that is connected to the circuit chip 20 by being fitted to the circuit chip 20.

The operation of the above configuration will be described. First, a criterion for determining whether or not the photocoupler 11 is deteriorated is set. Most of the deterioration of the signal transmission device such as the photocoupler 11 including the light emitting unit and the light receiving unit is the deterioration of the light emitting unit. In particular, among the reference clock, the data clock, and the end signal, the photocoupler 11 provided in the reference clock is more likely to deteriorate the light emitting unit 25 than the photocoupler 11 provided in the data clock and the end signal. This is because the light emitting diode 31 repeats light emission on and off more often, and / or the total light emission time is longer. Therefore, the deterioration of the light emitting diode 31 is diagnosed as the deterioration of the photocoupler 11.

A photocoupler of the same type as the photocoupler 11 to be diagnosed (same manufacturer and model) and which has already deteriorated and is recognized as a failure is specified as a reference value setting photocoupler. The reference value setting photocoupler may be mounted on the same substrate 12 as the photocoupler to be diagnosed, may be mounted on another substrate, or has already been removed as a replacement target. It may be a thing. The circuit chip of the photocoupler for setting the reference value is sandwiched by the clip 67 of the deterioration diagnosis device 15, the first current is supplied from the first power supply 56 to the light emitting portion, and the drive voltage is supplied from the second power supply 65 to the light receiving portion. .. The first current supplied from the first power supply 56 is increased or decreased by the variable resistor 57b of the adjustment circuit 57. In this case, it is preferable that the first current gradually increases rather than gradually decreases from the viewpoint of hysteresis characteristics. Therefore, in this example as well, the first current is gradually increased.

The light emitting diode emits light by supplying the first current to the light emitting unit, and the amount of light emitted by the light emitting diode is increased by gradually increasing the first current. The light from the light emitting diode is received by the photodiode 35 of the output side circuit unit 52 and converted into an electric signal. The current from the photodiode 35 is amplified by the amplifier 36 and sent to the transistor 37.

The output voltage of the light receiving unit is measured by the output side measuring unit described above. The output voltage is clearly different between the off state and the on state of the light receiving unit. The value is relatively high in the off state and relatively low in the on state, and the difference between these output voltages is large enough to be easily discriminated. Specifically, the output voltage in the on state is 20% or less of the output voltage in the off state. For example, in this example, when the light receiving unit is in the off state, the output voltage is detected by the voltmeter 66 as a high value of, for example, 2.5 V or more. When the amount of light emitted from the light emitting diode increases and the light receiving part switches from the off state to the on state, the output voltage drops sharply, and the voltmeter 66 has a detected value of 0.5 V at the highest, that is, 0.5 or less. Detected by. The value of the first current when the output voltage drops sharply in this way is detected by the ammeter 58 as the current value (hereinafter referred to as the minimum emission value) for the amount of light emitted to turn on the light receiving unit. .. The minimum light emission value increases as the deterioration of the light emitting diode progresses.

The deterioration reference value (hereinafter referred to as the deterioration judgment reference value) is higher than the minimum current value described in the data sheet of the reference value setting photocoupler, etc., and lower than the above-mentioned minimum emission value. Set to a value. For example, a value of 5% or more and 15% or less (for example, 10%) of the minimum emission value of the reference value setting photocoupler is subtracted from the minimum emission value of the reference value setting photocoupler as a margin, and the value obtained by this subtraction. Is used as the deterioration judgment reference value.

The margin is a current value in consideration of individual variation (individual difference) of the photocoupler 11 and the progress rate of deterioration, and may be obtained by, for example, the following method. Since the production equipment that operates continuously is often inspected and maintained on a regular basis, the minimum emission value of the photocoupler 11 to be diagnosed is obtained by the same method as described above for each inspection and maintenance. From the transition of the minimum emission value obtained in this way, the degree of deterioration is grasped. Then, the progress of deterioration expected by the next inspection and maintenance is estimated, and the margin is determined based on the estimated amount. In this way, the margin can be obtained and subtracted from the minimum emission value of the reference value setting photocoupler to obtain the deterioration determination reference value. For example, if it can be grasped that the minimum light emission value increases by up to 10% in one year, and if the next inspection and maintenance is one year later, the estimated current value of 10% can be used as a margin. As a result, it is preferable to subtract from the minimum emission value of the reference value setting photocoupler and use the value obtained by subtraction as the deterioration determination reference value. It should be noted that the deterioration judgment reference value does not have to be strictly set to the above value, and may be a value that can be well separated as a numerical value.

Most commercially available photocouplers have a maximum current value of 10 mA and a reference voltage of 5 V according to the specifications of the data sheet. In the case of such a photocoupler, "the output voltage drops sharply" means a case where the output voltage drops by 2 V or more per 1 mA of change in the first current.

In this example, the minimum current value described in the data sheet of the reference value setting photocoupler is 1 mA, and the minimum emission value is 4.50 mA. Further, 10% of the minimum emission value is set as the above margin. Therefore, 4.0 mA, which is smaller than the value calculated as 4.05 mA by 4.50 mA −0.45 mA and is well separated as a numerical value, is set as the deterioration determination reference value. In this way, the deterioration determination reference value is set as a determination criterion of whether or not the photocoupler 11 is deteriorated (see FIG. 5).

The photocoupler 11 to be diagnosed for deterioration is brought into a state in which the use (drive) is stopped, that is, the supply of an electric signal from the substrate 12 to the photocoupler 11 is stopped. In this state, the clip 67 sandwiches the circuit chip 20 of the photocoupler 11 mounted on the substrate 12. As a result, the first terminals 55a, 55b, the second terminals 61a, 61b, and the voltage supply terminal 61c are connected to the input terminals 21a, 21b, the output terminals 22a, 22b, and the power supply connection terminal 22c (connection process). The deterioration diagnosis device 15 is electrically connected to the photocoupler 11.

When a current is supplied to the photocoupler 11, the current flowing from the photocoupler 11 to the substrate 12 (hereinafter referred to as a return current) is somewhat different. Therefore, it is preferable to connect an ammeter (not shown) between the internal circuit 39A and the input terminal 21a to measure the return current, which is also measured in this example. The return current is measured by supplying a first current from the first power supply 56 to the light emitting unit 25 and measuring it with an ammeter provided between the internal circuit 39A and the input terminal 21a as described above. The first current when measuring the return current is 4 mA in this example, but is not limited to this example. The first current when measuring the return current may be set within the rated current value described in the data sheet of the photocoupler 11. Then, if the shunt ratio obtained by (current to the photocoupler 11): (return current) is known, the first current flowing through the photocoupler 11 can be obtained. For example, when the shunt ratio is 99: 1, 99/100 minutes of the first current is flowing to the photocoupler 11.

When the return current is extremely small, specifically, when it is 0.1 mA or less, this return current may be ignored and the return current may be regarded as 0 (zero) mA. In this example, it is less than 0.1 mA, so it is regarded as 0 mA. The details of the case where the return current is large, that is, the case where the return current is larger than 0.1 mA will be described later.

The minimum emission value of the photocoupler 11 is obtained in the same manner as when the minimum emission value of the reference value setting photocoupler is obtained. That is, it is as follows. The first current is supplied from the first power source 56 to the light emitting unit 25, and the drive voltage is supplied from the second power source 65 to the light receiving unit 26. The first current supplied from the first power supply 56 is increased or decreased by the variable resistor 57b of the adjustment circuit 57. In this case, it is preferable that the first current is gradually increased rather than gradually decreased, as described above, and is gradually increased in this example as well.

The light emitting diode 31 emits light by supplying the first current to the light emitting unit 25, and the amount of light emitted by the light emitting diode 31 increases by gradually increasing the first current. The output voltage of the light receiving unit 26 is measured by the above-mentioned output side measuring unit. When the light receiving unit 26 is off, the output voltage of the light receiving unit 26 is detected by the voltmeter 66 as a high value of 2.5 V or more in this example. When the amount of light emitted from the light emitting diode 31 increases and the light receiving unit 26 switches from the off state to the on state, the output voltage drops sharply, and at most 0.5, that is, 0.5 or less (20% of the off state). The following) is detected by the voltmeter 66. The value of the first current when the output voltage suddenly changes in this way is detected and specified by the ammeter 58 as the minimum light emission value required for light emission (specific step).

When the return current is large, that is, when the return current is larger than 0.1 mA, the return current is subtracted from the first current obtained in the specific step described above, and the value obtained by the subtraction is the light emission of the photocoupler 11. Set to the lowest value.

The minimum emission value of the photocoupler 11 is compared with the deterioration determination reference value obtained by using the reference value setting photocoupler, and it is diagnosed whether or not the photocoupler 11 is deteriorated (diagnosis step). Specifically, when the minimum emission value of the photocoupler 11 is equal to or higher than the deterioration determination reference value (see FIG. 5A), the photocoupler 11 is diagnosed as "deteriorated" and replaced with a new one. Will be done. When the light emission minimum value of the photocoupler 11 is less than the deterioration determination reference value (see FIG. 5B), the photocoupler 11 is diagnosed as "not deteriorated" and is used again. Even if it is diagnosed as "not deteriorated", it may be replaced with a new one if the period until the next deterioration diagnosis is scheduled to be long.

According to the above, deterioration is easily diagnosed in the state where the photocoupler 11 is mounted on the substrate 12 as the substrate assembly 10.

10 Board assembly 11 Photocoupler 12 Board 50 Deterioration diagnostic equipment 20 Circuit chip 21a, 21b Input terminal 22a, 22b Output terminal 22c Power connection terminal 25 Light emitting part 26 Light receiving part 31 Light emitting diode 35 Photodiode 36 Amplifier 37 Transistor 39A, 39B Circuit 51 Input side circuit unit 52 Output side circuit unit 55a, 55b 1st terminal 56 1st power supply 57 Adjustment circuit 57a Fixed resistance 57b Variable resistance 58 Ammeter 61a, 61b 2nd terminal 61c Voltage supply terminal 64 Resistance 65 2nd power supply 66 Voltmeter 67 Clip 68 1st arm 68a Protruding part 68t Tip part 69 Shaft rod 70 2nd arm 70a Protruding part 70t Tip part

Claims (9)

A first terminal pair connected to an input terminal pair of the light emitting unit of a signal transduction device including a light emitting unit and a light receiving unit that receives light from the light emitting unit.
A first power supply connected to the input terminal pair via the first terminal pair,
An adjustment circuit that increases or decreases the first current flowing from the first power supply to the light emitting unit, and
An input side circuit unit having an input side measuring unit for measuring the first current, and an input side circuit unit.
A second terminal pair connected to the output terminal pair of the light receiving unit and
A deterioration diagnostic apparatus including an output side circuit unit having an output side measuring unit for measuring an output voltage of the light receiving unit or a second current flowing through the light receiving unit via the second terminal pair. The deterioration diagnosis device according to claim 1, wherein the signal transmission device is a photocoupler. The deterioration diagnostic apparatus according to claim 1 or 2, wherein the adjustment circuit has a variable resistor connected in series with the first power supply. The output side measuring unit
A resistor that forms a series circuit with the light receiving part,
A second power supply connected to both ends of the series circuit,
The deterioration diagnostic apparatus according to any one of claims 1 to 3, further comprising a voltmeter for measuring a voltage between the output terminals of the light receiving unit. The light emitting unit and the light receiving unit are provided on one circuit chip with the input terminal pair and the output terminal pair protruding.
The circuit chip is provided on the substrate and
The deterioration diagnosis according to any one of claims 1 to 4, wherein the first terminal pair and the second terminal pair are connected to the input terminal pair and the output terminal pair of the signal transmission device on the substrate. apparatus. The deterioration diagnosis according to claim 5, wherein the first terminal pair and the second terminal pair are provided on a connecting member that is connected to the circuit chip by gripping or fitting the circuit chip. apparatus. The deterioration diagnosis device according to any one of claims 1 to 6, wherein the output side circuit unit further includes a voltage supply terminal for supplying a drive voltage to the light receiving unit. The deterioration diagnostic apparatus according to claim 7, wherein the voltage supply terminal is connected to a light receiving portion of the signal transmission device on the substrate, and any one of claims 5 and 6 is cited. It is a deterioration diagnosis method of a signal transmission device including a light emitting unit and a light receiving unit that receives light from the light emitting unit.
A connection step of connecting the first terminal pair of the deterioration diagnosis device according to any one of claims 1 to 8 to the input terminal pair and connecting the second terminal pair to the output terminal pair.
After the connection step, a specific step of increasing or decreasing the first current by the adjusting circuit and specifying the value of the first current when the output voltage or the second current changes by the output side measuring unit.
The first current specified in the specific step is compared with a preset reference value for deterioration, and if it is equal to or higher than the reference value, it is determined that the deterioration signal transmission device is deteriorated, and the reference value is determined. If it is less than, it is judged that it has not deteriorated.
Deterioration diagnostic method having.

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