RU974U1 - Temperature sensor with frequency output - Google Patents

Abstract

1. Temperature sensor with a frequency output, containing a constant magnetic field source, voltage source, semiconductor single crystal with injecting and ohmic current contacts on opposite surfaces, placed in the magnetic field of the specified source and connected by contacts to the voltage source, characterized in that it contains As a material of a semiconductor single crystal, high-resistance p-type silicon was used.

Description

FREQUENCY TESTER SENSOR

The invention is related to the field of measurement technology, in particular to temperature measuring devices, the effect of which is based on the use of thermosensitive elements.

Known diode and thermistor temperature-frequency converters containing a thermistor I or diode 2, connected to a special electronic circuit that converts changes in the parameters of sensitive thermocouples to the frequency of an alternating signal.

The disadvantages of such converters are the non-linearity of the output characteristic, relatively low sensitivity, the presence of an electronic circuit that determines the complexity of the device and the error of temperature measurement, as well as the dependence of the readings on the impedance of the line connecting the sensitive element to the electronic circuit.

A known temperature sensor selected as a prototype and containing a p-type germanium crystal in the form of a rod with a length of about 5 mm, equipped with two end contacts and placed between the poles of permanent magnets h. The basis of his work is the phenomenon of helical instability (oscillatory effect), in which the frequency of the oscillations of the current generated by the crystal by the crystal depends on the temperature T (mainly due to the temperature dependence of the mobility of charge carriers) at constant values of magnetic induction B and supply voltage If. A great influence on the oscillation frequency is exerted by the state of the crystal surface.

II U /

MKI SOIK 7/00

 / 1/5 & g v /

Duration of operation, due to a significant change in the state of the surface of germanium with time 4. One month after the manufacture of the sensor based on germanium, the temperature dependence of its vibration frequency changes so that the deviation from the initial values is II% 4.

The objective of the invention is to provide a sensor with increased sensitivity and stability of readings over time with a fully linear output characteristic in the temperature range - 10 -g-. + 55 ° C.

The problem is solved in that in a temperature sensor containing a constant magnetic field source, into which a semiconductor single crystal with injecting and ohmic contacts is placed on opposite surfaces, it is connected to a pulse voltage source, high-resistance p-type silicon is used as the material of the semiconductor single crystal, surface condition which is stabilized due to spontaneous build-up on it of a layer of silicon dioxide (StO). An increase in the sensitivity of the sensor and the linearity of the output characteristic is achieved due to a sharper temperature dependence of the electron mobility (p.) In silicon compared to germanium. For Germany jUn. ,

for silicon / JH. -. The invention is further illustrated in the drawing. In FIG. I shows a structural diagram of a proposed sensor with an output signal identification circuit. In FIG. 2 is a graph of the frequency of the output signal of this sensor on the ambient temperature. The proposed temperature sensor I (FIG. I) contains a magnetic field source 2, presented as a pair of counter-oriented opposite-pole magnetic rods, a p-type high-resistance silicon single crystal 3, located in the space between the two-pole magnetic poles of the source 2, current injecting and ohmic contact 4 formed on opposite surfaces

single crystal 3 so that the spatial orientation of the contacts / Г repeats the orientation of the opposite-pole rods of source 2: the magnetic field. A contact source 6 is connected to contact 4 through a resistor 5, and a resistor 5 is connected in parallel to a resistor 5. In the proposed sensor 1. those, the single crystal 3 has the following

dimensions: the distance between the contacts 4 is 0.85 glm, and the cross section is 0.8 x 1.1 mg.g. Each magnetic rod has

pasfviepH 8 X 10 X 10 mm. The single crystal 3 is placed in a magnetic field with induction I T. At the same time, the Fe – Nd – Dg alloy, which provides a rather high value of 1-valued induction, is needed to obtain the oscillistor effect in the argon in the temperature range above room temperature, as the material of the permanent magnets forming the source of the magnetic field.

The proposed temperature sensor with a frequency output of 1.5 operates as follows, a single crystal 3 of HIGH-SOA-I-SOUTH silicon r-type is in contact with the environment and, therefore, shades its temperature. A voltage pulse with an amplitude of 60 V is supplied from pins 6 to pins 4, which causes ischection of electrons and holes in the crystal 3 of pins 4. As a result, an electron-hole plasma appears in .3 single crystal. Since at 60 V the electric field E generated by 1.5 applied to the current contact, 4 by voltage, exceeds a threshold value that depends on the magnetic induction of B, in the single crystal 3 there is a helical instability of the electron-hole plasma 5. Moreover, in the external circuit, containing resistor 5, an alternating current appears, the frequency of which depends on the mobility of the charge carriers in the single crystal 3 and is several hundred kilohertz. The frequency of the alternating current with the help of resistor o is determined by the frequency meter 7. With increasing ambient temperature, the mobility of the charge carriers decreases, which leads to a decrease in the frequency of oscillations of the current in the circuit into which crystal 3 is connected.

59

According to the grading schedule of the daily dependence of the frequency колеб, the temperature fluctuates at the temperature t ° C (Fig. 2). The temperature is determined. At the supply voltage of the proposed ZJ sensor of 60 V, the frequency of the generated current oscillations varied from 425 to 225 kHz with a change in temperature from -10 to + 55 ° C, the sensitivity of the sensor was 3.1 kHz / ° C. In the general case, the sensitivity of the sensor and the linearity of the output characteristic are determined by the voltage U and the pair of Zetr SHLI of the semiconductor plasma. The optimal supply voltage U depends on the magnitude of the distance to the current by the contact current 4 of the semiconductor element 3 and decreases with decreasing this distance. The constant reading of the sensor over time at a constant temperature is determined by the stability of the surface state of the semiconductor element. Tests conducted over the course of the year showed high stability of napai-years of the semiconductor element. The deviation of the oscillation frequency from the initial values does not go beyond the limits of measurement errors, which is 3%.

The proposed temperature sensor has the following advantages. Due to the use of an ion-conductor, made of high-resistance creep or silt, with specific resistivity at room temperature J 2, the stability of the sensor parities in time is improved, the sensitivity of the sensor is increased (3.1 kHz / ° C compared to the prototype - I kHz / ° С) more than three times per liter and linearity of the output characteristic is achieved in a given temperature range. In addition, BpeiAs 1F1 is currently the most technologically advanced material for semiconductor electronics and has been developed for it with reliable surface protection,

Sources of information used in compiling

Il / / y / V v «I (/ J f

- I98I. - J 3. - S. 241-242.

3.Bondar V.M., Srshchorenko E.A., FsoElev VoV. Thermometer based on the oscillistor effect // 1TGZ. - ii 4. - S. 229-230 (prototype).

4.Bondar V.M., VladMyrOE V.V., Doskoch V.II. Strain gage based on oscillator effect // PTZ. - I98I. - 1st 3. - C, 244-246,

5.Vladimirov B.V., Volkov A.F., Yeylihov E.Z. Semiconductor Plasma, -M.: Atom1 / 1zdat, 1979.- 256s.

L / 5 &

Head of the Patent Department I.I. Gossen

Claims (1)

1. Temperature sensor with a frequency output, containing a constant magnetic field source, voltage source, semiconductor single crystal with injecting and ohmic current contacts on opposite surfaces, placed in the magnetic field of the specified source and connected by contacts to the voltage source, characterized in that it contains As a material of a semiconductor single crystal, high-resistance p-type silicon was used.