JPS6063431A - Temperature measuring device - Google Patents

Abstract

PURPOSE:To recognize immediately the abnormal state of a temperature measuring element by displaying a symbol corresponding to the abnormal state of the temperature measuring element on a display means. CONSTITUTION:The output of a temperature measuring element 1 such as a thermistor, a thermocouple, or the like is sent to an AD converter 3 through an amplifier 2 and is digitized and encoded to a BCD code by the converter 3, and this digital signal is sent to a decoder 4. The decoder 4 consists of a programmed logic array or the like, and the signal is converted to a code, which can be displayed as a number on a number display device 6, and is sent to a driver circuit 5. The number display device 6 consists of an LED or a liquid crystal display device having, for example, a 7-segment display part. The temperature measured by the temperature measuring element 1 is displayed digitally as a number on this number display device 6. An abnormality detecting circuit 7 is connected directly to the temperature measuring element 1, and abnormalities of open-circuit trouble, short-circuit trouble, etc. are detected by this circuit and are sent as an open-circuit trouble signal, a short-circuit trouble signal, etc. to the decoder 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature control device for a thermometer or a temperature relay that measures temperature and displays it digitally.

With conventional temperature measuring devices, when an abnormality in short circuit mode or open mode occurs in a temperature measuring element such as a thermistor or thermal lightning pair, the impedance change of the 1m element is detected and a lamp is turned on to indicate the abnormality of the temperature measuring element. I'm trying to turn it on. In such a conventional 21i1 degree measuring device, it is necessary to attach letters indicating the details of the abnormality to the panel surface of the device for each abnormal lamp. When an abnormality lamp lights up, it is necessary to read the symbols and letters attached to the side of the abnormality lamp to determine whether the abnormality is in short-circuit mode or open mode, making the work of confirming the abnormality cumbersome. .

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a temperature measurement method that can immediately recognize an abnormal state of a temperature measurement element.

Examples of the present invention will be described below. In Figure 1, the output of a temperature measuring element 1 such as a thermistor or thermocouple is sent to an AD (Analog-to-Digital) converter 3 via an amplifier 2, where it is digitized and encoded into a BCD code. This digital signal is sent to the decoder 4. The decoder 4 is composed of a programmed logic array, etc., and converts the code into a code that can be displayed numerically on the numerical display device 6.
send to The numeric display device ff16 is composed of, for example, an LED or a liquid crystal display device having a 7-segment display section as shown in FIG. 4, which will be described later.

In this way, the temperature measured by the temperature measuring element 1 is digitally displayed as a number on the numerical display device 6.

Further, an abnormality detection circuit 7 is provided which is directly connected to the temperature measuring element 1, and this circuit detects an abnormality such as an open failure or a short circuit failure of the temperature measuring element, and sends the detected abnormality to the decoder 4 as an open failure signal and a short circuit failure signal. I'm trying to send it. When these fault signals are input, the decoder 4 stops the conversion for normal temperature display and outputs a specific signal to indicate a short circuit fault or an open fault.

Note that the detected failure signal may not only be sent to the decoder 4, but may also be outputted to the outside as an abnormality alarm signal through the output circuit 83.

When the temperature measuring device is configured as a temperature relay, it has a temperature setting device 81 and a relay 82 as shown in FIG. 1, but it can also be applied to such a temperature relay.

In addition, in FIG. 1, the abnormality detection circuit 7 is directly connected to the temperature measuring element 1, but as shown in FIG. Alternatively, as shown in FIG. 3, an abnormality in the temperature measuring element may be detected based on the output state of the AD converter 3. In addition, when detecting an abnormality by the output of the AD converter, the third
As shown in the figure, it is also possible to configure the abnormality detection circuit 7 together with the decoder 4 as a program in a programmed logic array.

For example, as shown in Figure 4, an abnormality can be displayed on the numerical display device by indicating a short circuit failure with rsHJ (abbreviation for SHORT).
If each open failure is displayed as "oP" (abbreviation for OPEN), it will be easier to understand when reading.

Furthermore, in a multi-point scanning temperature measuring device as shown in FIG. I! l-temperature elements Ia, 1b, lc... and an amplifier 2a that amplifies their outputs, respectively.

2b, 2c, etc., and the outputs of these amplifiers are inputted to the AD converter 3 via the data bus 31. A signal indicating whether the amplifier is being scanned is output as a predetermined coded signal, which is decoded by a decoder 92 and sent to the driver circuit 9.
3, the number display device 94 for displaying the number of the l1ll temperature point is driven. This numerical display device 94 for displaying the temperature measurement point number
A display unit 61 is constituted by the temperature display number display device 6 and the temperature display number display device 6. In the case of such a multipoint temperature measuring device, it
! ! Since the abnormal state is displayed at the same time as the number of the I-temperature point, it is possible to immediately know whether or not the temperature measuring element is malfunctioning.

According to the invention, 8I! l An abnormality in the temperature sensor is detected, a signal corresponding to the abnormal state of the temperature sensor is derived from the detection means, and a symbol corresponding to the abnormal state of the temperature sensor is displayed on the display means according to this output, so temperature measurement is possible. The content of the abnormality in the element can be visually recognized immediately, and the abnormal state can be immediately responded to.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a first embodiment of the present invention, Fig. 21 is a block diagram showing a second embodiment of the invention, and Fig. 3 shows a part of a third embodiment of the invention. Block diagram, Figure 4 (a), (
B) is a plan view showing a display example, and FIG. 5 is a rib block diagram showing a fourth embodiment of the present invention. 1.1a, 1b, 1c... Temperature measuring elements 2a, 2
b, 2c...... Increase 11] Vessel 3...
...AD converter 4 ...Decoder 5 ...Driver circuit 6 ...Numeric display device 7 ...Abnormality detection circuit special z1 Applicant Tateishi Electric Co., Ltd. Meeting 1 Figure 1 θl Figure 2 Figure 3 Figure 4 (A) c mouth J

Claims (1)

[Claims] (1) In a temperature measuring device comprising a temperature measuring element', an amplifying means for amplifying the output of the temperature measuring element, and a display means, an abnormality of the temperature measuring element is detected and a response is taken to the abnormal state of the temperature measuring element. A temperature measuring device comprising: a detection means for outputting a signal; and a symbol corresponding to an abnormal state of the temperature measuring element is displayed on the display means.