SU1580295A1 - Apparatus for inputting information from temperature sensitive elements - Google Patents

Abstract

The invention relates to automation and can be used as part of automated data acquisition and process control systems (APCS). The purpose of the invention is to increase the reliability of the device by quickly monitoring the integrity of the electrical circuits of temperature sensors. For this, a device for inputting information from temperature sensors, containing a switch 2 channels of temperature measurement sensors, a decoder 4 of a temperature sensor number, a normalizing temperature converter 3, the input of which is connected to the output of switch 2, a voltage generator 1, whose output is in reverse polarity connected to the input of the normalizing converter 3 via an additional channel of the switch 2. With normally working channels of temperature measurement, the control computing complex (UHC) indicates the temperature level corresponding to the level of signals taken from the sensors. In the event of a breakage of any sensor, the UVK indicates the temperature corresponding to the signal level of the generator 1. 1 il.

Description

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The invention relates to automation and can be used in an automated data collection and process control system (APCS), in particular in a group temperature meter.

The aim of the invention is to increase the reliability of the device by operatively monitoring the integrity of the electrical circuits of the temperature sensors.

The drawing shows a block diagram of the proposed device.

The device contains a voltage generator 1, a switchboard 2 channels of temperature sensors, working and additional channels, a normalizing temperature converter 3 and a decoder 4 numbers of a temperature sensor.

For simplicity, we take the total number of switching channels to be 16.

The inputs of the switch 2 are connected to the information inputs of the device, the output is connected to the input of the normalizing converter 3, and the control input is connected to the output of the decoder 4, the output of the normalizing converter 3 and the input of the decoder 4 is connected to the output and input of the device respectively, the output of the voltage generator 1 is connected to the input the normalizing converter 3 through the additional channel of the switch 4.

The device works as follows.

In the initial state, the ACU through the encoder 4 sets the code 0000. The first channel is connected to the input of the normalizing converter 3. After the Start command, the ACU receives the signal of the normalizing converter 3 corresponding to the temperature of the first channel and displays its value. Then UVK displays code 1111 (voltage generator is switched on the input). UVK holds the code 1111 on

the time required for normal operation of the normalizing converter (usually b 0.5-1 s). Then UVK for the time If If sets the code 0001 (the second channel is connected), after which the alarm sets the code 1111. Thus, the switching of each working channel alternates with the switching of the channel to which the generator 1 is connected. With normally working temperature measurement channels, the UVK will indicate temperature, appropriate

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signal levels taken from the sensors. If any channel is faulty (there is an open circuit), when connecting a faulty channel, the ACU will indicate the temperature corresponding to the level of the generator signal, since the normalizing converter will remember the level of the signal of the generator connected to the faulty channel.

In this case, it is required to select a generator voltage so that the corresponding temperature is obviously different from the possible temperatures of the object being monitored.

For example, it is required to control the temperature of the bearings and the gas of the K-400 compressor, which boosts the contact gas, from which isoprene is released. The temperature inside the compressor during normal operation is 50-80 ° C (at various points).

TBgda instead of the generator, you can install a simple jumper connecting the inputs + and - of the normalizing converter. In this case, on the faulty channel, the UVK will record the ambient temperature, which even in the hot season in the control room, where the UVK is installed, does not exceed 35 ° C, i.e. Obviously lower temperatures inside the compressor. But, let's say, in the same compressor, it is necessary to control the temperature of the cooling water (15-20 ° C), and the temperature

environment in the apparatus during the winter time of 20 ° C. Consequently, a simple jumper replacing the generator, in this case is not suitable. It is necessary to give such a signal from generator 1 that the corresponding temperature is obviously different from the operating temperatures of the compressor, which are 15-80 ° C. In this case, it is impractical to choose a signal that is larger than the possible limit of measured temperatures, since the ACU is set to issue an alarm and block the compressor when the temperature at certain points exceeds a certain value. Therefore, the generator signal must be selected to

temperature is of the order of 0-10 C. Therefore, in order for the signal level to be mV (thermocouple chromel-copel), it is turned on. in reverse polarity, otherwise the signal level

generator will be: 1 mV. In this case, a galvanic cell, for example, 1.5 V with a voltage divider, can act as a generator. It is also possible to use a thermocouple as a generator, similar to the working one, but included in the reverse polarity. This thermocouple

Claims (1)

Invention Formula I A device for entering information from temperature sensors containing a decoder, a normalizing converter, a switch, the inputs of which are connected to the information inputs of the device, and the output is connected to the input of normals must be placed in an environment where the temperature of the JQ world converter, the control is about 2 times higher than the ambient temperature in the equipment room. This may be, for example, the temperature inside the casing of the power supply unit of the switchboard or the ACU (near the transformer, 15 The switch input is connected to the output of the decoder, the output of the normalizing converter and the input of the decoder are connected to the output and input of the device, respectively, characterized in that, in order to increase reliability by operatively monitoring the integrity of the electrical circuits of the temperature sensors, a voltage generator is introduced into the device , the output of which in reverse polarity is connected to the input of the normalizing converter through an additional channel of the switch. radiator, power transistor temperature (l / 70 C). In this case, the level The signal from such a thermocouple will correspond to a temperature of 0-5 C. Thus, the device is able to provide on-line continuous monitoring of the working channels of temperature measurement during operation, identify the faulty channel and thereby increase the reliability of the device. 25 20 transducer control The switch input is connected to the output of the decoder, the output of the normalizing converter and the input of the decoder are connected to the output and input of the device, respectively, characterized in that, in order to increase reliability by operatively monitoring the integrity of the electrical circuits of the temperature sensors, a voltage generator is introduced into the device which in the reverse polarity is connected to the input of the normalizing converter through an additional channel of the switch.