JPH03218504A - temperature control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a temperature control device that requires precise temperature control, such as an open device for chromatography.

(Example) Conventional technology In chromatography ovens and the like, a heater is used as a heat source, and a commercial power supply voltage is applied to this heater. The commercial power supply voltage in Japan is 100μ, but the voltage value differs depending on the country.

Since it can be used in any country with different voltage values, for example, in order to use in countries with power supply voltages of 100V and 120V, it is sufficient to use a heat with a rating of 120V or higher. However, in this case, even if there is no problem with the heater being damaged, the power generated by the heater varies depending on the voltage, so the same temperature control circuit will not be able to precisely control the temperature because the temperature ripple will become large. Conventionally, this has been dealt with by using a down transformer or replacing the heater itself, depending on the power supply voltage used.

(c) Problems to be Solved by the Invention In the conventional temperature control device described above, it is time-consuming to replace the device parts depending on the power supply voltage for each country or destination, and the use of a down transformer is There are problems in that it increases the weight and also increases the cost of the device.

This invention was made in view of the above-mentioned problems, and aims to provide a temperature control device that can be used with various power supply voltages without requiring the replacement of parts or the use of down transformers. There is.

(2) Means and operation for solving the problem As shown in the schematic configuration in FIG. 1, the temperature control device of the present invention includes a heater 1, a temperature setting means 6 for setting a target temperature, and a temperature control device near the heater. a temperature detecting means 3 for detecting the temperature of the heater, a temperature control stage 2 for controlling energization from the power supply to the heater so that the detected temperature becomes the set temperature based on a control constant, and a power supply voltage having a predetermined control constant. is applied to the heater to calculate the rate of increase in temperature detected by the temperature detecting means, and the power supply voltage is determined from the calculated rate of increase, and a corresponding temperature control constant is determined. and temperature control constant determining means 5.

In this temperature control device, first, a power supply voltage is applied to the heater, the temperature is detected by the temperature detection means, and the temperature increase rate is determined by the temperature increase rate calculation means. The higher the power supply voltage is, the higher the rate of temperature rise will be, so find the relationship between several power supply voltages and the rate of increase in salinity in advance, select the power supply voltage based on the rate of temperature rise on site, and perform temperature control corresponding to that power supply voltage. A constant is determined, and temperature control is performed based on this temperature control constant.

(E) Examples The present invention will be explained in more detail with reference to Examples below.

FIG. 2 is a block diagram of a temperature control device according to an embodiment of the present invention. This temperature control device includes a power supply circuit 1l that inputs an AC power supply voltage, a heater 12, and a power supply circuit 1 when turned on.
Thyristor 1 that applies voltage from 1 to heater 12 and energizes it.
3. Temperature sensor l4 that detects the ambient temperature of the heater 12;
An A/D converter 15 that converts the analog temperature signal detected by the temperature sensor 14 into a digital signal, a CPU 6 that executes control operations, a memory I 7, an operation unit 18 for inputting set temperature, etc., and a zero cross signal. A generator 19 is provided. The CPU 6 also has a function of calculating the rate of increase in temperature detected by the temperature sensor 14, a function of determining the power supply voltage from the calculated rate of temperature increase, and determining a corresponding control constant.

Here, the control constants are, for example, P, ■, D constants, etc.

In this temperature control device, temperature control constants are first initialized for ACIOOV after power is turned on.

Then, the set value is input and operation is started. in general,
At the start of operation, there is a large temperature difference between the set value and the measured value, so
100% power is applied to heater l2. Here, the heater power is adjusted by the ratio of the on/off periods of the thyristor 13. For example, in the waveform shown in FIG.
The diagonal line indicates the on period of the thyristor 13. When the thyristor 13 is on for the entire period, the power is 100%, when the on and off periods are alternated by one cycle, the power is 50%, and when the thyristor is off for the entire period, the power is 0%.

The temperature change is measured within the time period during which the measured value rises to the set value at this initial stage, and the rate of temperature rise is determined. The relationship between the power supply voltage and the temperature rise rate is determined in advance through experiments, and the memory 17
Therefore, the input power supply voltage can be determined from the calculated temperature rise rate (e.g. AC100V, AC120V, A
C220V). Once the power supply voltage is known, the control constant determined corresponding to each voltage and stored in the memory 17 is read out in accordance with the power supply voltage, and this control constant is used for subsequent temperature control.

(f) Effects of the invention According to this invention, the temperature rise rate is calculated at the start of operation,
Based on this temperature rise rate, the input power supply voltage is known, the corresponding temperature control constant is determined, and control is performed using this common control constant from now on, so it is not necessary to replace parts or install a down transformer. Precise temperature control can be achieved for any power supply voltage without the need for Furthermore, since there is no need to set the power supply voltage using a switch or the like, troubles such as forgetting to set the voltage can be avoided.

[Brief explanation of drawings]

Fig. 2 is a schematic diagram showing the general configuration of the temperature regulating device of the present invention, Fig. 2 is a prong diagram showing the configuration of the temperature regulating device according to the embodiment, and Fig. 3 is a schematic diagram showing the configuration of the temperature regulating device of the present invention. It is a figure for explaining. 1: Heater section, 2: Temperature control section, 3: Temperature detection means 4: Temperature increase rate calculation means, 5: Control constant determination means, 6: Temperature setting means.

Claims (1)

[Claims] (1) A heater, a temperature setting means, a temperature detection means for detecting the temperature near the heater, and a temperature control for controlling the supply of electricity from a power source to the heater so that the detected temperature becomes the set temperature based on a control constant. temperature increase rate calculation means for applying a power supply voltage of a predetermined control constant to the heater and calculating the rate of increase in temperature detected by the temperature detection means; and determining the power supply voltage from the calculated rate of increase. , and temperature control constant determining means for determining a corresponding temperature control constant, and performs temperature control using the determined temperature control constant.