JP2015130458A - Drive control circuit and analyzer equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive control circuit and an analyzer equipped with the same which can excellently prevent burning and overheat of an inductive load.SOLUTION: Temperature of an inductive load or its ambient temperature is detected by a temperature sensor 9, and on the basis of an input signal from the temperature sensor 9, an energization allowable time or an energization prohibition time is set. On the basis of the set energization allowable time or energization prohibition time, an energization control circuit 72 controls energization to the inductive load. When energization of the inductive load is stopped as an energization allowable time has passed while energizing the inductive load, energization can be stopped before burning or overheat occurs to the inductive load. On the other hand, when energization of the inductive load is prohibited until the energization allowable time passes while not energizing the inductive load, energization is not started before a time necessary for cooling down the inductive load passes after energization is stopped, burning and overheat of the inductive load can excellently be prevented.

Description

  The present invention relates to a drive control circuit for controlling the driving of an inductive load and an analyzer equipped with the drive control circuit.

  For example, in an analyzer such as a total nitrogen total phosphorus meter, a fluorescent X-ray analyzer, and a spectrophotometer, an inductive load may be energized to maintain the state of an actuator such as a motor or a solenoid valve (for example, See Patent Document 1 below). The inductive load is composed of a coil or a solenoid, and electromagnetic energy can be converted into mechanical motion by changing the energization state of the inductive load.

  When energizing an inductive load, copper loss occurs due to the electrical resistance of the inductive load itself, and heat is generated. Further, when changing the energization state to the inductive load, iron loss (hysteresis loss and eddy current loss) is generated with the fluctuation of the magnetic flux density and heat is generated. Such heat generation causes the temperature of each part of the actuator to rise. However, if the temperature rise is large, inductive load burnout or irreversible modification of other components (magnetic material or insulating material) As a result, the function may be deteriorated.

  Therefore, in order to solve the above problems, for example, a structure in which the actuator does not easily generate heat may be employed, or control in which the actuator does not generate heat may be performed. For the structure where the actuator does not generate heat easily, the thermal capacity is increased by increasing the current capacity by increasing the inductive load, adopting a structure that allows heat to escape to the outside of the actuator, or a material with high thermal conductivity. Or the actuator may be air-cooled with a cooling fan.

  Further, in a solenoid or the like, it is also possible to reduce the amount of heat generated by adopting a structure that can maintain the state even when energization is stopped, such as a latch structure. In this case, it is conceivable to employ a ball plunger mechanism using, for example, a ball, a compression spring, and a screw.

  On the other hand, as a control in which the actuator does not easily generate heat, for example, it is conceivable to limit the energization time to the inductive load by a CR time constant circuit that starts charging upon receiving a drive signal (see, for example, Patent Document 2 below). ). Further, in a solenoid or the like, while energization is performed continuously, switching to a pulse current is conceivable when maintaining the state (for example, refer to Patent Document 3 below).

JP 2008-20418 A Japanese Utility Model Publication No. 62-12913 Japanese Utility Model Publication No. 5-25704

  However, the following problems may occur when the actuator has a structure that does not easily generate heat. First, when the inductive load is increased in size, there is a problem that miniaturization of the product is hindered. Further, in the case of a structure in which heat is released from the surface of the actuator, there is a possibility that gas is released from the component parts of the product due to an increase in ambient temperature.

  In this case, for example, in the configuration using an actuator for the light amount adjusting slit mechanism in the spectrophotometer as in Patent Document 1, the gas released from the component parts of the product due to heat may affect the analysis result. is there. In addition, there may be a need for safety considerations such as providing a mechanism for preventing the user of the product from being burned when the surface of the actuator becomes hot.

  On the other hand, when the actuator is controlled so as not to generate heat, the following problems may occur. First, when the energization time to the inductive load is limited using a CR time constant circuit or the like, the time required for cooling the inductive load after the set energization time has elapsed and the energization was stopped. There is a possibility of receiving an energization instruction before it elapses.

  In this case, there is a problem that burning and overheating of the inductive load cannot be prevented. In particular, when an energization instruction is received immediately after the set energization time has elapsed, the inductive load cannot be cooled, and the above-described problems are likely to occur. In addition, when the ambient temperature of a product using the actuator rises, the set energization time may not be appropriate.

  When a pulse current is used when maintaining a state in a solenoid or the like, there is a problem that it is difficult to set the duty ratio of the pulse current appropriately. In other words, if the duty ratio of the pulse current is excessively lowered to prevent the solenoid from burning, there is a possibility that the required state holding force cannot be obtained. On the other hand, if the duty ratio of the pulse current is increased too much to generate the required state holding force, the solenoid may not be burned out.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a drive control circuit that can satisfactorily prevent inductive load burning and overheating, and an analyzer equipped with the drive control circuit.

  A drive control circuit according to the present invention is a drive control circuit for controlling driving of an inductive load, and includes a temperature sensor for detecting the temperature of the inductive load or an ambient temperature thereof, and the inductive load. An energization control unit for controlling energization of the power supply, an energization allowable time for allowing energization to the inductive load based on an input signal from the temperature sensor, and energization for prohibiting energization to the inductive load An energization setting processing unit that sets at least one of the prohibited times, and the energization control unit energizes the inductive load when the energization allowable time has elapsed when energizing the inductive load. And at least one of a process for prohibiting energization of the inductive load until the energization prohibit time elapses when the inductive load is not energized.

  According to such a configuration, energization to the inductive load can be controlled based on the energization allowable time or the energization prohibition time set from the temperature of the inductive load or the ambient temperature. If energization of the inductive load is stopped when the inductive load is energized, the energization load can be stopped before the inductive load is burned or overheated if the energization load is stopped. On the other hand, if energization to the inductive load is prohibited until the energization prohibition time elapses when the inductive load is not energized, the time necessary for cooling the inductive load elapses after the energization is stopped. Since energization is not started before, burning and overheating of the inductive load can be satisfactorily prevented.

  In particular, the energization allowable time or the energization prohibition time is automatically set based on the temperature of the inductive load detected by the temperature sensor or its ambient temperature, so that even if the ambient temperature changes Time can be secured, and inductive load burnout and overheating can be satisfactorily prevented.

  The drive control circuit may further include a difference calculation processing unit that calculates the difference by comparing an input signal from the temperature sensor with a predetermined threshold value. In this case, the energization setting processing unit may set at least one of the energization allowable time and the energization prohibition time based on the difference calculated by the difference calculation processing unit.

  According to such a configuration, since the temperature of the inductive load or its ambient temperature can be detected more accurately based on the difference between the input signal from the temperature sensor and the predetermined threshold, the energization allowable time or energization Prohibition time can be set appropriately.

  The drive control circuit may further include a comparison processing unit that compares an input signal from the temperature sensor with a plurality of threshold values. In this case, the energization setting processing unit may set at least one of the energization allowable time and the energization prohibition time based on a comparison result by the comparison processing unit.

  According to such a configuration, based on the comparison result between the input signal from the temperature sensor and a plurality of threshold values, the threshold value that approximates the input signal from the temperature sensor is specified, and the temperature of the inductive load is determined based on the threshold value. Or since the ambient temperature can be detected more accurately, the energization allowable time or the energization prohibition time can be set appropriately.

  When the temperature sensor is for detecting the ambient temperature of the inductive load, when the energization setting processing unit starts energizing the inductive load, an input signal from the temperature sensor, A parameter table for predicting the temperature of the inductive load based on an input signal from the temperature sensor, the previous energization duration to the inductive load, and the previous energization to the inductive load are stopped. The energization allowable time may be set based on the energization stop time afterwards.

  According to such a configuration, when energization to the inductive load is started, the energization continuation time to the previous inductive load and the energization stop time after the energization to the previous inductive load is stopped. Based on the current inductive load temperature. Then, based on the specified current inductive load temperature, the ambient temperature of the inductive load detected by the temperature sensor, and the parameter table, the temperature of the subsequent inductive load can be predicted. The allowable time can be set appropriately. Such a configuration is suitable for an environment where the ambient temperature of the inductive load is likely to change.

  The analyzer according to the present invention includes the drive control circuit and an inductive load whose drive is controlled by the drive control circuit.

  According to such a configuration, since it is possible to prevent the gas from being released from the component parts of the product due to heat from the inductive load, the gas does not affect the analysis result, and the analysis is performed well. It can be performed.

  In particular, analyzers installed in environments where the ambient temperature is likely to change, such as analyzers installed outdoors (for example, total nitrogen and total phosphorus meters) and analyzers installed indoors in an environment without air conditioning equipment. As described above, the energization setting processing unit stops the input signal from the temperature sensor, the parameter table, the previous energization duration to the inductive load, and the previous energization to the inductive load. A configuration in which the energization allowable time is set based on the energization stop time after that is suitable.

  According to the present invention, since it is possible to control energization to the inductive load based on the energization allowable time or the energization prohibition time set from the temperature of the inductive load or its ambient temperature, Overheating can be prevented satisfactorily.

It is the block diagram which showed the structural example of the analyzer which concerns on one Embodiment of this invention. It is the block diagram which showed the structural example of the drive control circuit. FIG. 3 is a block diagram illustrating a configuration example of an energization control circuit in FIG. 2. It is the flowchart which showed the flow of the process performed by the electricity supply control circuit, when supplying with electricity to a solenoid. It is the flowchart which showed the flow of the process performed by the electricity supply control circuit, when not energizing a solenoid. It is the block diagram which showed the structural example of the drive control circuit which concerns on another embodiment. FIG. 7 is a block diagram illustrating a configuration example of an energization control circuit in FIG. 6. FIG. 6 is a block diagram illustrating a configuration example of a drive control circuit according to another embodiment. It is a figure for demonstrating the aspect at the time of a calculation part calculating energization allowable time, and has shown the relationship between the temperature of a solenoid, and time.

  FIG. 1 is a block diagram illustrating a configuration example of an analyzer according to an embodiment of the present invention. This analyzer is, for example, a spectrophotometer, and includes a light source 1, a diffraction grating 2, a slit mechanism 3, a sample chamber 4, a detector 5, an actuator 6, a drive control circuit 7, and the like. However, the present invention is not limited to a spectrophotometer and can be applied to any other analyzer.

  Among the components described above, for example, the light source 1, the diffraction grating 2, the slit mechanism 3, the sample chamber 4, the detector 5, and the actuator 6 are accommodated in the dark box 8. In the dark box 8, it is comprised so that the light from the outside may not enter.

  The light emitted from the light source 1 is split into light for each wavelength in the diffraction grating 2. The slit mechanism 3 is provided with a slit plate 31 in which a slit for allowing light from the diffraction grating 2 to pass is formed. The slit plate 31 can be displaced in a direction intersecting the optical axis of the light from the diffraction grating 2, and the amount of light passing through the slit can be adjusted by displacing the slit plate 31. it can. The light that has passed through the slit mechanism 3 is applied to the sample in the sample chamber 4, and transmitted light or reflected light from the sample is detected by the detector 5.

  The actuator 6 is for displacing the slit plate 31 of the slit mechanism 3 by converting electromagnetic energy into mechanical motion, and includes a solenoid 61 as an inductive load. The solenoid 61 is formed of a coil wound in a cylindrical shape, and generates a magnetic field inside when energized. An iron core (not shown) is provided inside the solenoid 61, and the iron core can be attracted by a magnetic force by changing the energization state of the solenoid 61. The drive of the solenoid 61 is controlled by the drive control circuit 7.

  FIG. 2 is a block diagram illustrating a configuration example of the drive control circuit 7. In this example, the drive control circuit 7 is configured by a logic circuit, and includes a drive circuit 71, an energization control circuit 72, a difference circuit 73, a threshold voltage generation circuit 74, and the like. However, the drive control circuit 7 is not limited to a logic circuit, and may be configured such that the CPU performs processing as described below.

  The drive circuit 71 is a circuit for supplying a drive current to the solenoid 61 to drive it. The energization control circuit 72 can supply a drive current from the drive circuit 71 to the solenoid 61 by inputting an energization signal to the drive circuit 71 based on the energization instruction signal. The energization instruction signal is input to the energization control circuit 72 based on processing in the analyzer or an instruction from the outside.

  In the present embodiment, it is possible to set a maximum value (energization allowable time) for which energization to the solenoid 61 is continued and a minimum value (energization prohibition time) for prohibiting energization of the solenoid 61. Thereby, the energization control circuit 72 switches the input of the energization signal to the drive circuit 71 based on the energization instruction signal, the energization allowable time, and the energization prohibition time.

  Specifically, when an energization instruction signal is input, the energization control circuit 72 inputs an energization signal to the drive circuit 71 unless it is within the energization prohibition time. Thereafter, while the energization instruction signal is being input, the energization signal is input from the energization control circuit 72 to the drive circuit 71 as long as the energization allowable time has not elapsed. Even within the allowable energization time, if the input of the energization instruction signal is stopped, the input of the energization signal from the energization control circuit 72 to the drive circuit 71 is stopped.

  The energization control circuit 72 can perform the above processing based on the input signal from the difference circuit 73. The difference circuit 73 is a difference calculation processing unit that calculates the difference by comparing the input signal from the temperature sensor 9 with a predetermined threshold value (voltage value). The threshold value is generated by a threshold voltage generation circuit 74 associated with the difference circuit 73 as a predetermined value.

  The temperature sensor 9 may be one that can directly detect the temperature of the solenoid 61 by being provided in the actuator 6 itself, or provided around the solenoid 61 (for example, inside or outside the dark box 8). Therefore, the ambient temperature may be detected. The threshold value can be set in a different manner depending on whether the temperature sensor 9 directly detects the temperature of the solenoid 61 or detects the ambient temperature of the solenoid 61.

  For example, when the temperature sensor 9 directly detects the temperature of the solenoid 61, the relationship between the temperature detected by the temperature sensor 9 and the time until the solenoid 61 reaches the maximum allowable temperature, and the temperature sensor The relationship between the detected temperature by 9 and the time during which the temperature of the solenoid 61 decreases to the original temperature may be created in advance as a first parameter table, and the threshold value may be set based on the first parameter table.

  On the other hand, when the temperature sensor 9 detects the ambient temperature of the solenoid 61, the relationship between the temperature detected by the temperature sensor 9 and the temperature rise amount of the solenoid 61 per unit time, and the temperature detected by the temperature sensor 9. And the temperature drop amount per unit time of the solenoid 61 may be created in advance as a second parameter table, and the threshold value may be set based on the first parameter table and the second parameter table.

  FIG. 3 is a block diagram showing a configuration example of the energization control circuit 72 of FIG. The energization control circuit 72 includes, for example, an energization allowable time selection circuit 72a, an energization prohibition time selection circuit 72b, an energization allowance time output circuit 72c, an energization prohibition time output circuit 72d, an energization permission determination circuit 72e, and an energization signal generation circuit 72f. ing.

  Here, the energization permission determination circuit 72e and the energization signal generation circuit 72f constitute an energization control unit for controlling energization to the solenoid 61. The energization allowable time selection circuit 72a, the energization prohibition time selection circuit 72b, the energization allowance time output circuit 72c, and the energization prohibition time output circuit 72d set the energization allowance time and the energization prohibition time based on the input signal from the temperature sensor 9. An energization setting processing unit to be set is configured.

  The energization signal generation circuit 72 f generates an energization signal and inputs it to the drive circuit 71, thereby supplying a drive current from the drive circuit 71 to the solenoid 61. The energization permission determination circuit 72e generates an energization signal in the energization signal generation circuit 72f and permits energization to the solenoid 61, or energizes the solenoid 61 without generating an energization signal in the energization signal generation circuit 72f. Determine whether to prohibit.

  The difference between the input signal from the temperature sensor 9 and the threshold generated by the threshold voltage generation circuit 74 is input from the difference circuit 73 to the energization allowable time selection circuit 72a and the energization prohibition time selection circuit 72b. The energization allowable time output circuit 72c includes a plurality of energization allowable time generation circuits 72g that generate different energization allowable times. The energization prohibition time output circuit 72d includes a plurality of energization prohibition time generation circuits 72h that generate different energization prohibition times.

  The energization allowable time selection circuit 72a AD-converts the difference input from the difference circuit 73, and selects the energization allowable time generation circuit 72g according to the difference. As a result, the energization allowable time generated by the selected energization allowable time generation circuit 72g is input (set) from the energization allowable time output circuit 72c to the energization permission determination circuit 72e.

  At this time, the larger the difference between the input signal from the temperature sensor 9 and the threshold value generated by the threshold voltage generation circuit 74, that is, the higher the temperature of the solenoid 61 than the threshold value, the shorter energization allowable time is set. . For example, a CR time constant circuit or a timer counter circuit can be used to output the allowable energization time from the allowable energization time output circuit 72c.

  The energization allowable time generation circuit 72g generates an energization allowable time when an energization instruction signal is input. The energization permission determination circuit 72e allows the energization signal generation circuit 72f to generate an energization signal and permit energization to the solenoid 61 if the energization allowable time has not elapsed while the energization instruction signal is input. When the energization allowable time has elapsed, the energization permission determination circuit 72e prohibits the energization of the solenoid 61 without causing the energization signal generation circuit 72f to generate an energization signal.

  The energization prohibition time selection circuit 72b AD-converts the difference input from the difference circuit 73 and selects the energization prohibition time generation circuit 72h according to the difference. Thus, the energization prohibition time generated by the selected energization prohibition time generation circuit 72h is input (set) from the energization prohibition time output circuit 72d to the energization permission determination circuit 72e.

  At this time, the larger the difference between the input signal from the temperature sensor 9 and the threshold value generated by the threshold voltage generation circuit 74, that is, the higher the temperature of the solenoid 61 than the threshold value, the longer the energization prohibition time is set. . For example, a CR time constant circuit or a timer counter circuit can be used to output the energization inhibition time from the energization inhibition time output circuit 72d.

  The energization prohibition time generation circuit 72h generates an energization prohibition time when the input of the energization instruction signal is stopped. When the energization prohibition time has not elapsed when the energization instruction signal is input, the energization permission determination circuit 72e inhibits energization of the solenoid 61 without causing the energization signal generation circuit 72f to generate an energization signal. When the energization prohibition time has elapsed, the energization permission determination circuit 72e causes the energization signal generation circuit 72f to generate an energization signal and permits energization of the solenoid 61.

  Thus, the energization allowable time selection circuit 72a, the energization prohibition time selection circuit 72b, the energization allowance time output circuit 72c, and the energization prohibition time output circuit 72d as the energization setting processing unit are based on the difference calculated by the difference circuit 73. Set the energization allowable time and energization prohibition time. Based on the set energization allowance time and energization prohibition time, the energization permission determination circuit 72e and the energization signal generation circuit 72f as the energization control unit control energization to the solenoid 61.

  Specifically, when the solenoid 61 is energized, processing for stopping the energization of the solenoid 61 is performed when the energization allowable time has elapsed. On the other hand, when the solenoid 61 is not energized, processing for prohibiting energization of the solenoid 61 is performed until the energization prohibition time elapses.

  FIG. 4 is a flowchart showing the flow of processing performed by the energization control circuit 72 when the solenoid 61 is energized. FIG. 5 is a flowchart showing the flow of processing performed by the energization control circuit 72 when the solenoid 61 is not energized. As shown in FIGS. 4 and 5, the energization control circuit 72 performs different processes depending on whether the solenoid 61 is energized or not.

  That is, when the solenoid 61 is energized, it is monitored whether the energization instruction signal is turned off and whether the energization allowable time has elapsed (steps S101 and S102 in FIG. 4). On the other hand, when the solenoid 61 is not energized, it is monitored whether the energization instruction signal is turned on and whether the energization prohibition time has elapsed (steps S201 and S202 in FIG. 5).

  As shown in FIG. 4, when the solenoid 61 is energized, the energization instruction signal is turned off (Yes in step S101), or the energization allowable time has elapsed before the energization instruction signal is turned off. (Yes in step S102), a process of stopping energization of the solenoid 61 at that time is performed (step S103). At this time, the energization prohibition time is set based on the input signal from the temperature sensor 9 (step S104), and thereafter, the processing after step S201 in FIG. 5 is performed.

  As shown in FIG. 5, when the solenoid 61 is not energized, the energization instruction signal is turned on (Yes in step S201), and when the energization prohibition time has elapsed (Yes in step S202), the time In step S203, a process for starting energization of the solenoid 61 is performed. At this time, the energization allowable time is set based on the input signal from the temperature sensor 9 (step S204), and thereafter, the processing after step S101 in FIG. 4 is performed.

  Thus, in this embodiment, the energization to the solenoid 61 can be controlled based on the energization allowable time and the energization prohibition time set from the temperature of the solenoid 61 or its ambient temperature. If energization of the solenoid 61 is stopped when the solenoid 61 is energized, the energization can be stopped before the solenoid 61 is burned or overheated. On the other hand, if energization to the solenoid 61 is prohibited until the energization prohibition time elapses when the solenoid 61 is not energized, the energization is stopped before the time necessary for cooling the solenoid 61 elapses after the energization is stopped. Is not started, the burnout and overheating of the solenoid 61 can be satisfactorily prevented.

  In particular, the energization allowable time and the energization prohibition time are automatically set based on the temperature of the solenoid 61 detected by the temperature sensor 9 or its ambient temperature, so that proper energization is possible even when the ambient temperature changes. Time can be secured and the burnout and overheating of the solenoid 61 can be satisfactorily prevented.

  In the present embodiment, the temperature of the solenoid 61 or the ambient temperature thereof can be detected more accurately based on the difference between the input signal from the temperature sensor 9 and a predetermined threshold value. Time can be set appropriately.

  When the drive control circuit 7 as in the present embodiment is applied to the analysis device, it is possible to prevent the gas from being released from the component parts of the product due to the heat from the solenoid 61, so that the gas is analyzed. The analysis can be performed satisfactorily without affecting the results. For example, when the actuator 6 is housed together with various optical components in the dark box 8 as in the present embodiment, it is possible to effectively prevent gas from being generated in the dark box 8 and affecting the analysis result. Can do.

  FIG. 6 is a block diagram illustrating a configuration example of the drive control circuit 7 according to another embodiment. In this example, the drive control circuit 7 is configured by a logic circuit, and includes a drive circuit 171, an energization control circuit 172, a plurality of comparison circuits 173, a plurality of threshold voltage generation circuits 174, and the like. However, the drive control circuit 7 is not limited to a logic circuit, and may be configured such that the CPU performs processing as described below.

  The drive circuit 171 is a circuit for supplying a drive current to the solenoid 61 to drive it. The energization control circuit 172 can supply a drive current from the drive circuit 171 to the solenoid 61 by inputting an energization signal to the drive circuit 71 based on the energization instruction signal. The energization instruction signal is input to the energization control circuit 172 based on processing in the analyzer or an instruction from the outside.

  In the present embodiment, the energization allowable time and the energization prohibition time can be set similarly to the above embodiment, and the energization control circuit 172 sends the drive circuit 171 to the drive circuit 171 based on the energization instruction signal, the energization allowable time, and the energization prohibition time. The input of the energization signal is switched.

  Specifically, when an energization instruction signal is input, the energization control circuit 172 inputs an energization signal to the drive circuit 171 unless it is within the energization prohibition time. Thereafter, while the energization instruction signal is being input, the energization signal is input from the energization control circuit 172 to the drive circuit 171 unless the allowable energization time has elapsed. Even within the allowable energization time, if the input of the energization instruction signal is stopped, the input of the energization signal from the energization control circuit 172 to the drive circuit 171 is stopped.

  The energization control circuit 172 can perform the above processing based on input signals from the plurality of comparison circuits 173. The plurality of comparison circuits 173 are comparison processing units that compare the input signals from the temperature sensor 9 with different threshold values (voltage values). The threshold value is generated as a predetermined value by the threshold voltage generation circuit 174 associated with each comparison circuit 173. Similarly to the above-described embodiment, the threshold value differs depending on whether the temperature sensor 9 directly detects the temperature of the solenoid 61 or whether the ambient temperature of the solenoid 61 is detected. Can be set.

  FIG. 7 is a block diagram showing a configuration example of the energization control circuit 172 of FIG. The energization control circuit 172 includes, for example, an energization allowable time selection circuit 172a, an energization prohibition time selection circuit 172b, an energization permission determination circuit 172c, and an energization signal generation circuit 172d.

  Here, the energization permission determination circuit 172c and the energization signal generation circuit 172d constitute an energization control unit for controlling energization to the solenoid 61. The energization allowable time selection circuit 172a and the energization prohibition time selection circuit 172b constitute an energization setting processing unit that sets the energization allowance time and the energization prohibition time based on the input signal from the temperature sensor 9.

  The energization signal generation circuit 172d generates an energization signal and inputs it to the drive circuit 171, thereby supplying a drive current from the drive circuit 171 to the solenoid 61. The energization permission determination circuit 172c allows the energization signal generation circuit 172d to generate an energization signal and permits energization to the solenoid 61, or energizes the solenoid 61 without generating the energization signal in the energization signal generation circuit 172d. Determine whether to prohibit.

  The comparison results from the plurality of comparison circuits 173 are input to the energization allowable time selection circuit 172a and the energization prohibition time selection circuit 172b. The energization allowance time selection circuit 172a includes an energization allowance time selection interface 172e and a plurality of energization allowance time generation circuits 172f that generate different energization allowance times. The energization prohibition time selection circuit 172b includes an energization prohibition time selection interface 172g and a plurality of energization prohibition time generation circuits 172h that generate different energization prohibition times.

  The energization allowable time selection circuit 172a specifies a threshold value that approximates the input signal from the temperature sensor 9 based on the comparison results of the plurality of comparison circuits 173, and selects the energization allowable time generation circuit 172f according to the threshold value. Thereby, the energization allowable time generated by the selected energization allowable time generation circuit 172f is input (set) from the energization allowable time selection circuit 172a to the energization permission determination circuit 172c.

  At this time, the energization allowable time is set to be shorter as the threshold specified as a value approximate to the input signal from the temperature sensor 9 is larger, that is, as the temperature of the solenoid 61 is higher. For example, a CR time constant circuit or a timer counter circuit can be used to output the allowable energization time from the allowable energization time selection circuit 172a.

  The energization allowable time generation circuit 172f generates an energization allowable time when an energization instruction signal is input. The energization permission determination circuit 172c allows the energization signal generation circuit 172d to generate an energization signal and permit energization to the solenoid 61 if the energization allowable time has not elapsed while the energization instruction signal is input. When the energization allowable time has elapsed, the energization permission determination circuit 172c prohibits the energization of the solenoid 61 without causing the energization signal generation circuit 172d to generate an energization signal.

  The energization prohibition time selection circuit 172b specifies a threshold value that approximates the input signal from the temperature sensor 9 based on the comparison results of the plurality of comparison circuits 173, and selects the energization prohibition time generation circuit 172h according to the threshold value. As a result, the energization prohibition time generated by the selected energization prohibition time generation circuit 172h is input (set) from the energization prohibition time selection circuit 172b to the energization permission determination circuit 172c.

  At this time, the energization prohibition time is set to be longer as the threshold value specified as a value approximate to the input signal from the temperature sensor 9 is larger, that is, as the temperature of the solenoid 61 is higher. For example, a CR time constant circuit or a timer counter circuit can be used to output the energization inhibition time from the energization inhibition time selection circuit 172b.

  The energization prohibition time generation circuit 172h generates an energization prohibition time when the input of the energization instruction signal is stopped. When the energization prohibition time has not elapsed when the energization instruction signal is input, the energization permission determination circuit 172c inhibits energization of the solenoid 61 without causing the energization signal generation circuit 172d to generate an energization signal. When the energization prohibition time has elapsed, the energization permission determination circuit 172c causes the energization signal generation circuit 172d to generate an energization signal and permits energization of the solenoid 61.

  In this way, the energization allowable time selection circuit 172a and the energization prohibition time selection circuit 172b as the energization setting processing unit set the energization allowable time and the energization prohibition time based on the comparison results by the plurality of comparison circuits 173. Then, the energization permission determination circuit 172c and the energization signal generation circuit 172d as the energization control unit control energization to the solenoid 61 based on the set energization allowable time and energization prohibition time.

  Specifically, when the solenoid 61 is energized, processing for stopping the energization of the solenoid 61 is performed when the energization allowable time has elapsed. On the other hand, when the solenoid 61 is not energized, processing for prohibiting energization of the solenoid 61 is performed until the energization prohibition time elapses.

  As described above, also in the present embodiment, the energization to the solenoid 61 can be controlled based on the energization allowable time and the energization prohibition time set from the temperature of the solenoid 61 or its ambient temperature. And overheating can be satisfactorily prevented.

  In particular, in this embodiment, a threshold value that approximates the input signal from the temperature sensor 9 is specified based on the comparison result between the input signal from the temperature sensor 9 and a plurality of threshold values, and the temperature of the solenoid 61 is determined based on the threshold value. Or since the ambient temperature can be detected more accurately, the energization allowable time and the energization prohibition time can be set appropriately.

  FIG. 8 is a block diagram showing a configuration example of the drive control circuit 7 according to still another embodiment. In this example, the drive control circuit 7 includes a drive circuit 271 and an energization control circuit 272. In the present embodiment, the temperature sensor 9 is for detecting the ambient temperature of the solenoid 61.

  The drive circuit 271 is a circuit for supplying a drive current to the solenoid 61 to drive it. The energization control circuit 272 can supply a drive current from the drive circuit 271 to the solenoid 61 by inputting an energization signal to the drive circuit 271 based on the energization instruction signal. The energization instruction signal is input to the energization control circuit 272 based on processing in the analyzer or an instruction from the outside.

  In this embodiment, the energization allowable time can be set, and the energization control circuit 272 switches the input of the energization signal to the drive circuit 271 based on the energization instruction signal and the energization allowable time.

  Specifically, when an energization instruction signal is input, the energization control circuit 272 inputs the energization signal to the drive circuit 271, and thereafter, while the energization instruction signal is input, as long as the energization allowable time does not elapse. The energization signal is input from the energization control circuit 272 to the drive circuit 271. Even within the allowable energization time, if the input of the energization instruction signal is stopped, the input of the energization signal from the energization control circuit 272 to the drive circuit 271 is stopped.

  The energization control circuit 272 includes, for example, an energization control unit 272a, a calculation unit 272b, a storage unit 272c, and an external input interface 272d. The energization instruction signal and the input signal from the temperature sensor 9 are input to the energization control circuit 272 via the external input interface 272d. The energization control unit 272a and the calculation unit 272b can be configured by a CPU.

  The computing unit 272b includes an energization allowable time calculation unit 272e for calculating the energization allowable time. The storage unit 272c stores the parameter table 272f for predicting the temperature of the solenoid 61 based on the input signal from the temperature sensor 9, the previous energization duration 272g to the solenoid 61, and the energization to the previous solenoid 61. The energization stop time 272h after the stop is stored.

  As the parameter table 272f, the above-described second parameter table can be used. The energization continuation time 272g can be obtained by counting the time after starting energization of the solenoid 61 with a counter. On the other hand, the energization stop time 272h can be obtained by counting the time after the energization of the solenoid 61 is stopped with a counter.

  When the energization to the solenoid 61 is started, the calculation unit 272b sets the allowable energization time based on the input signal from the temperature sensor 9, the parameter table 272f, the energization duration 272g, and the energization stop time 272h. An energization setting processing unit is configured. The energization control unit 272a controls energization to the solenoid 61 based on the energization allowable time set by the calculation unit 272b.

  FIG. 9 is a diagram for explaining an aspect when the calculation unit 272b calculates the allowable energization time, and shows the relationship between the temperature of the solenoid 61 and time. As shown in FIG. 9, when energization to the solenoid 61 is started, the energization continuation time 272g to the previous solenoid 61 and the energization stop time 272h after the energization to the previous solenoid 61 are stopped are as follows. If it is known, the current temperature of the solenoid 61 can be specified.

  When energization of the solenoid 61 is started, the temperature of the solenoid 61 rises. However, since the amount of temperature rise per unit time of the solenoid 61 differs depending on the ambient temperature, the energization allowable time also changes. Become. For example, as shown in FIG. 9, when the ambient temperature of the solenoid 61 is T1, the amount of temperature increase per unit time of the solenoid 61 is larger than when the ambient temperature is T2, and the time to reach the maximum allowable temperature is also shorter. It has become.

  Therefore, in this embodiment, an input signal from the temperature sensor 9 is obtained by using a parameter table (second parameter table) 272f that represents the relationship between the temperature detected by the temperature sensor 9 and the amount of temperature increase of the solenoid 61 per unit time. Based on this, the temperature of the solenoid 61 is predicted, and the allowable energization time can be set.

  As described above, in this embodiment, when energization of the solenoid 61 is started, the energization continuation time 272g of the previous solenoid 61 and the energization stop time 272h after the energization of the previous solenoid 61 is stopped. Based on this, the current temperature of the solenoid 61 can be specified. Then, the temperature of the subsequent solenoid 61 can be predicted based on the specified current temperature of the solenoid 61, the ambient temperature of the solenoid 61 detected by the temperature sensor 9, and the parameter table 272f. Time can be set appropriately.

  The configuration as in the present embodiment is suitable for an environment where the ambient temperature of the solenoid 61 is likely to change. For example, in an analyzer installed in an environment where the ambient temperature is likely to change, such as an analyzer installed outdoors such as a total nitrogen total phosphorus meter or an analyzer installed indoors in an environment without air conditioning equipment. Can suitably adopt the configuration of the present embodiment.

  In the above embodiment, as the temperature sensor 9 for detecting the ambient temperature of the solenoid 61, the temperature sensor 9 originally provided in the analyzer can be used. For example, in the total nitrogen total phosphorus meter, when the ambient temperature is measured using the temperature sensor 9 as a room temperature sensor and the performance guarantee temperature is exceeded, the record may be left in the analysis data. Further, in the fluorescent X-ray analysis apparatus, there is a case where the ambient temperature is measured using the temperature sensor 9 as a room temperature sensor, and when the ambient temperature exceeds a threshold value, the cooling fan speed is increased. Thus, if the drive of the solenoid 61 is controlled using the temperature sensor 9 originally provided in the analyzer, the cost can be reduced.

  However, the inductive load is not limited to the solenoid 61, and the present invention can also be applied to the case where the drive of the actuator 6 having another inductive load such as a coil is controlled. Further, the configuration is not limited to the configuration described in the above embodiment as long as at least one of the energization allowable time and the energization prohibition time is set based on the input signal from the temperature sensor 9. The configuration may be such that only one of the time and the energization prohibition time is set.

  In the above embodiment, the case where the drive control circuit 7 according to the present invention is applied to the analysis apparatus has been described. However, the present invention is not limited to the analysis apparatus but can be applied to apparatuses other than the analysis apparatus. In particular, the present invention is effective in an application in which it is allowed to automatically limit the operation interval of the actuator 6.

DESCRIPTION OF SYMBOLS 1 Light source 2 Diffraction grating 3 Slit mechanism 4 Sample chamber 5 Detector 6 Actuator 7 Drive control circuit 8 Dark box 9 Temperature sensor 31 Slit plate 61 Solenoid 71 Drive circuit 72 Energization control circuit 72a Energization allowable time selection circuit 72b Energization inhibition time selection circuit 72c Energization allowable time output circuit 72d Energization prohibition time output circuit 72e Energization permission determination circuit 72f Energization signal generation circuit 72g Energization allowable time generation circuit 72h Energization inhibition time generation circuit 73 Difference circuit 74 Threshold voltage generation circuit 171 Drive circuit 172 Energization control circuit 172a Energization Allowable time selection circuit 172b Energization prohibition time selection circuit 172c Energization permission determination circuit 172d Energization signal generation circuit 172e Energization allowance time selection interface 172f Energization allowance time generation circuit 172g Energization prohibition time selection interface 1 72h Energization inhibition time generation circuit 173 Comparison circuit 174 Threshold voltage generation circuit 271 Drive circuit 272 Energization control circuit 272a Energization control unit 272b Arithmetic unit 272c Storage unit 272d External input interface 272e Allowable energization time calculation unit 272f Parameter table 272g Energization duration 272h Energization Stop time

Claims (5)

A drive control circuit for controlling driving of an inductive load,
A temperature sensor for detecting the temperature of the inductive load or its ambient temperature;
An energization control unit for controlling energization to the inductive load;
An energization setting processing unit that sets at least one of an energization allowable time for allowing energization to the inductive load and an energization prohibition time for prohibiting energization to the inductive load based on an input signal from the temperature sensor. And
The energization control unit is configured to stop energizing the inductive load when the energization allowable time has elapsed when energizing the inductive load, and not energizing the inductive load. Sometimes, at least one of the processes for prohibiting energization of the inductive load is performed until the energization prohibit time elapses. A difference calculation processing unit for calculating the difference by comparing the input signal from the temperature sensor with a predetermined threshold;
The drive control circuit according to claim 1, wherein the energization setting processing unit sets at least one of the energization allowable time and the energization prohibition time based on the difference calculated by the difference calculation processing unit. . A comparison processing unit that compares an input signal from the temperature sensor with a plurality of threshold values;
The drive control circuit according to claim 1, wherein the energization setting processing unit sets at least one of the energization allowable time and the energization prohibition time based on a comparison result by the comparison processing unit. The temperature sensor is for detecting the ambient temperature of the inductive load,
The energization setting processing unit, when starting energization to the inductive load, a parameter for predicting the temperature of the inductive load based on the input signal from the temperature sensor and the input signal from the temperature sensor The energization permissible time is set based on a table, the energization continuation time for the previous inductive load, and the energization stop time after the previous energization of the inductive load is stopped. The drive control circuit according to claim 1. The drive control circuit according to any one of claims 1 to 4,
And an inductive load whose drive is controlled by the drive control circuit.

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