JPS6394317A - Temperature controller - Google Patents

Abstract

PURPOSE:To prevent the failure of an object to be controlled due to a mistake in connection by detecting and alarming the mistake in connection of the reverse connection of a temperature detector using a thermocouple. CONSTITUTION:An output from a temperature detecting sensor 2 is inputted to a control part 5 through an A/D converter 4. In the control part 5, the level relation of a temperature T1 at the time of turning a power source on and a set temperature T2 is detected according to the relation of time. For instance, when the temperature T2 to be elevated is lowered at the time of viewing from the detected temperature T1, or when the temperature T2 to be lowered is elevated at the time of viewing the detector temperature T1, it is decided to be an abnormality in connection and displayed on a display means 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a temperature controller, and is particularly suitable for application to one having a thermocouple conventional temperature detection sensor.

[Conventional technology] Conventionally, thermocouples have been used as temperature regulators.
This converts the voltage signal corresponding to the temperature from the thermocouple by a voltage signal converter, converts it into digital data, and inputs it to a control unit composed of a microcomputer. compared to
According to the deviation, heating and cooling devices are driven to control the temperature to the set temperature.

[Problems to be Solved by the Invention] Generally speaking, thermocouples detect temperature by connecting one end of two types of metal, leaving the other end open, and measuring the voltage between the open terminals. Therefore, although it is implemented, the connection direction is fixed to one direction.

When such a thermocouple is mounted in a temperature controller, if it is mistakenly connected in the opposite direction, the detection output changes in the opposite direction to the original direction of change that occurs when the temperature rises. In other words, even though the temperature is rising, the input to the temperature regulator body changes in the opposite direction, so the temperature regulator body senses the opposite when the temperature is falling and operates to raise it. . Therefore, even when the temperature is already higher than the predetermined set temperature, the control section controls the drive section to further increase the temperature, which may cause a malfunction.

The present invention has been made in consideration of the above points, and when the temperature detection sensor is connected in the opposite direction, it can quickly detect and display this fact, and prevent the occurrence of malfunctions. The purpose of this paper is to propose a temperature regulator that can

[Means for Solving the Problems] In order to solve the problems, in the present invention, the control section 5 calculates the Detected temperature'r
In the temperature regulator 1 that controls the controlled object 8 so that the temperature T10N matches the set temperature T2, the control unit 5 controls the detected temperature T11 when the set temperature T2 is higher (lower) than the detected temperature T10N when the power is turned on. When the temperature drops (rises) by a predetermined temperature T or more from the detected temperature T10N when the power is turned on, the display means 11 is operated to notify an abnormality.

[Function] Set temperature T 2 and temperature T 1 ON when the power supply 9 is turned on
If the magnitude relationship between the two is known, it can be determined whether the detected temperature T1 after turning on increases or decreases. Therefore, if the detected temperature T1 is falling even though it should be rising, or if it is rising when looking at the detected temperature T1 although it should be falling, it is determined that there is a connection error. It is displayed on the display means 11. As a result, it becomes possible to prevent breakdowns due to excessive rise or fall.

[Example code] Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 shows a temperature controller 1 as a whole, and a detection signal from a temperature detection sensor 2 consisting of a thermocouple is sent to a voltage signal converter 3.
given to. ? , the voltage signal converter converts the voltage signal into a voltage signal within a predetermined range so that even if sensors 2 with different detection ranges are connected, the voltage signal can be applied without changing other configurations.

The voltage signal converted in this way is further converted into digital data T by the analog/digital conversion circuit 4.
After the signal is converted into 1, it is applied to a control section 5 having a microcomputer configuration.

During normal operation, the control unit 5 operates the input device r! based on the program stored in the program memory 5b. The deviation indicated by the detected temperature (temperature indicated by digital data) Tl with respect to the set temperature T2 from i6 is determined, and a drive unit ( ) DR that eliminates the deviation is applied to the drive unit 7 according to the deviation.

The drive section 7 operates the controlled object 8 according to this signal DR, and is thus controlled so that the detected temperature T1 becomes the set temperature T2.

In addition to the above configuration, this embodiment has a connection monitoring configuration for the temperature detection sensor 2. That is, the program memory 5b of the control unit 5 stores the connection monitoring program shown in FIG.
f, II Ogoribu 5 CPU 5a starts the program in step S1, proceeds to the next step S2, fetches the detected temperature Tl0N when the power supply 9 is turned on, and uses this temperature T
It is determined whether l0N is within a predetermined range of temperature.

Here, the temperature in the predetermined range is, for example, the temperature when the temperature controller 1 is not in operation at a place where it is installed,
For example, 0 to 50 degrees can be considered. This step S
As soon as a negative result is obtained as a result of the judgment in step 2, step S is performed.
Proceed to step 3 to end the connection monitoring program. On the other hand, if a certain result is obtained, input the target set temperature T2 in step S4! ! Import from 6 to je.

Next, in step S5, it is determined whether the fetched set temperature T2 is specified to be higher than the temperature at which a connection abnormality is determined. If a negative result is obtained, the program proceeds to step $3 and ends the program. Conversely, if it is larger, the detected temperature at that time] 1 is fetched in step S6, and in the next step $7, the power supply is It is determined whether the temperature T11 just taken in is lower than a predetermined temperature 'r (for example, 10 degrees) compared to the temperature T10N when the switch 9 is turned on.

As a result, if a positive result is obtained, the process proceeds to step S8,
The display drive unit 10 is driven to display a message on the display means 11 indicating that the connection direction of the temperature detection sensor 2 is opposite, and the program is ended in step S3. On the other hand, if a negative result is obtained as a result of the judgment in step S7, the process proceeds to step S9 and the temperature T
It is determined whether li has risen by a predetermined temperature T (for example, 10 degrees) or more compared to the temperature 'I' 10 N when the power is turned on.

As a result, if a positive result is obtained, it is determined that the sensor 2 is normally connected, and the process proceeds to step S3 to terminate the program. On the other hand, if a negative result is obtained, the process returns to step S5 described above.

This program was formed based on the ideas described below. First, when the power supply 9 is turned on, the detected temperature Tl0N is often room temperature. For example, when the set temperature T2 is higher than room temperature, if the detected temperature Tl0N when turned on is lower than room temperature, an abnormality other than a connection abnormality may occur. Therefore, it was decided to leave the abnormality display operation by another routine, and when the temperature was higher than the room temperature, it was assumed that the power supply 9 was turned on again immediately after being turned off, and the connection was already confirmed. Second, if the set temperature T2 is set higher than the room temperature, the detected temperature T1 should rise, so the connection is determined to be normal when the predetermined temperature T rises. . Here, it is desirable that the predetermined temperature T be set to a value that does not cause a judgment error, for example, about 10 degrees. Thirdly, when the temperature drops by a predetermined amount T from the room temperature, it is determined that this is due to a reverse connection, and a message is displayed. Fourth, when the temperature Tl0N immediately after turning on is close to the set temperature T2,
In this case, the determination operation is not performed because there is a risk of erroneous determination and the time required to proceed to the temperature adjustment main routine is unnecessarily long. Fifth, when the sensor 2 is incorrectly connected, it is during manufacturing and assembly, or when the sensor 2 is being replaced.In that case, the power supply 9 is generally turned off, so it is difficult to determine whether there is a connection error. It is now done when power supply 9 is turned on.

Assume that in the above configuration having a program formed based on the above idea, the connection of the sensor 2 is reversed at the time of manufacturing and assembly. At this time, after that, the first power supply 9
When the switch is turned on, the program shown in FIG. 2 is started, the temperature T 10 N at the time of the switch on is taken in, and then it is determined that the temperature Tl0N is within a predetermined range and that the set temperature T2 is higher than the predetermined temperature. Detection temperature after confirmed 'rl
i is taken in, and the detected temperature '11 is taken in repeatedly until it can be determined whether it has risen by a predetermined temperature 'r (10 degrees) or more or fallen by a predetermined temperature or more compared to the initial temperature TlOH.In this case, conversely, Since it is connected, the temperature will eventually drop to a predetermined temperature T (10 degrees) or more, and as a result, the display drive unit 10 will drive the display means 11 to display a message indicating the abnormality.

Therefore, according to the above-described embodiment, it is possible to notify the user that the sensor 2 is connected in reverse, and to prevent the control object 8, sensor 2, etc. controlled by the temperature regulator 1 from malfunctioning. can be prevented.

In the above-described embodiment, a thermocouple is used as the temperature detection sensor 2, but the present invention is not limited to this. Can be widely applied to regulators.

In addition, in the above embodiment, the case where the set temperature 1゛2 is higher than the detected temperature Tl0N when turned on is described;
On the other hand, the present invention can be applied even when the value is low.

[Effects of the Invention] As described above, according to the present invention, an abnormality in the connection of the temperature detection sensor is notified, so that various circuits and components, including the controlled object, can be prevented from malfunctioning due to excessive temperature rise or fall. Such situations can be effectively avoided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the temperature regulator according to the present invention, and FIG. 2 is a flowchart showing the procedure for constantly monitoring the contact F1''A of the temperature detection sensor 2. 2...Temperature detection sensor, 5 ...Control unit, 6...Input device, 8...Controlled object, 9...Power supply, 11...
Display means. Applicant Nippon Fenol Co., Ltd. Agent Nobuyuki Kudo (1 other person) Benro 1 expense sensor 20 Boiling monitor? +Korihaya 2 old

Claims (1)

[Scope of Claims] A temperature regulator in which a control unit controls a controlled object so that the detected temperature matches the set temperature based on the deviation between the temperature detected by a temperature detection sensor and the set temperature from an input device, The control section operates the display means when the set temperature is higher (lower) than the detected temperature when the power is turned on, and when the detected temperature falls (rises) by a predetermined temperature or more than the detected temperature when the power is turned on. A temperature controller characterized by being configured to notify an abnormality.