SU1444623A1 - Multielement thermal converter - Google Patents

Abstract

The invention relates to electrical measuring technology and allows an increase in the signal-to-noise ratio. A multi-element thermocouple transducer contains a thermocouple battery consisting of thermocouples arranged in layers, connected in series in each layer. The layers of thermocouples are connected in parallel on the contact pads. In a thermocouple battery, branches of the same type of conductor are located one above the other. Between the layers of thermocouples are placed sections of the heater connected in series. The resistance of each section of heater R (. Is determined by the ratio Ru, R (n-l), where R is the resistance of the heater; n is the number of layers of thermocouples. 2 ill. O "5

Description

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I The invention relates to electrical measuring equipment and can be used to measure alternating current values (voltage, current, power) by comparing them with an effective value with equivalent DC values.

The purpose of the invention is to increase the signal / noise ratio.

FIG. 1 shows a multi-element thermoconverter, general view; in fig. 2 is a section A-A (rotated 90) in FIG. one.

The thermal converter contains a dielectric substrate 1, on which heater 2 is placed, a thermocouple battery of thermocouples connected in series with branches 3 and 4 of opposite conductivity, located in layers and isolated from each other by dielectric layers 5, contact pads 6 and 7 of the heater and thermocouple battery respectively. In a thermocouple battery, branches 3 of one type of conductivity are located one above the other, and branches 4 of a different type of conductivity are also located one another. over friend. The branches 3 and 4 serially connected in one layer are connected in parallel on the contact pads 7. Between the thermocouple layers in the dielectric layers 5, there are sections of heater 2 connected in parallel) on the contact pads 6. At the same time, the resistance of a separate section of the heater is determined by

R RH (p-1)

about

(1) 40

where RU is the resistance of one section of the heater;

R ((- resistance of the heater; n - number of layers of thermocouples.

Thermocouple works as follows.

When current passes through heater 2, Joule heat is released in it, which heats the hot junctions of thermocouples formed by branches 3 and 4.

Due to the fact that the heater 2 is complete in the form of areas located in the dielectric layers 5 between the thermocouple layers, the joule heat generated in the heater is more efficiently used. In this device, the thermal resistance between each

The portion of the heater 2 and the adjacent thermocouple layers are insignificant, which contributes to an increase in the heating temperature of the hot junctions of thermocouples in layers. In addition, since none of the sections of the heater is in direct contact with the substrate 1, its shunting effect on the heat flux is reduced, which also contributes to an increase in the temperature of hot junctions.

The execution of sections of a heater with resistance determined by the relation (1) contributes to the equal distribution of Joule heat in the sections of the heater and more uniform heating of the hot junctions of thermocouples of all layers.

Due to the fact that, in a thermocouple battery, layers are placed on top of another on the other branch of the same type of conductivity, parasitic heat transfer along dielectric layers 5 separating thermocouple layer 1 is reduced. In the proposed device, the possibility of a short circuit between adjacent layers of thermocouples other branches of the same type of conductivity are located. This allows dielectric layers to be made with a minimum thickness, which helps to reduce parasitic heat flux through the dielectric layers. In addition, it increases the reliability of the device.

The connection in parallel on the contact pads 7 thermocouples connected in series in one layer, formed by branches 3 and 4, reduces the resistance of the thermocouple battery. This makes it possible to reduce the thermal noise of the thermocouple battery resulting from the random motion of free electrons. The increase in the number of layers further reduces the resistance of the thermocouple battery.

As a result of making a thermocouple battery with overlapping branches of the same conductivity type and heater from the sections located between the thermocouple layers, an increase in sensitivity and decrease in thermal noise and, as a result, an increase in the signal-to-noise ratio occurs. Due to the temperature difference along thermocouples, thermopower is generated, which is a measure of the effective current value.

The multielement thermal converter is made on a mica substrate using the methods of thermal vacuum evaporation and high-frequency injection. A thermocouple heater of two connected parallel sections is made of nichrome, a thermocouple battery of 60 thermocouples — connected in parallel in three layers of 20 thermocouples connected in series with antimony branches of bismuth, a dielectric layer between thermocouple layers of polytetrafluoroethylene.

Claims (1)

From the data characterizing a specific thermocouple, the resistance of the heater is 120 ± 10 Ω; thermopile resistance 600 + 50 Ohm; sensitivity 4 V / W - it follows that the proposed thermocouple with a sufficiently high sensitivity has a low output resistance. Invention Formula A multielement thermoconverter containing a dielectric substrate, a heater with contact pads, and a thermocouple battery with contact pads are thermocouples arranged in layers, connected in series in each layer and insulated by dielectric layers, so that the signal-to-noise ratio, in a thermocouple battery, branches of one type of conductivity are located one above the other, thermocouples of each layer are connected in parallel on the contact pads, and the heater is made of a separate x sections connected in series and arranged between the layers of thermocouples, the resistance of each individual portion of the heater is defined by the relation To „11„ (n-f). aRH p resistance of a separate section of the heater; heater resistance; - the number of ci ev thermocouples.  - “7 1 BUT R .Z Editor A. Ogar Compiled by V., Agapova Tehred A. Kravchuk Order 6498/41 Circulation 607 . VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Proofreader M.Sharoshi Subscription