SU271428A1 - THERMISTOR THERMAL SENSITIVE DEVICE - Google Patents

Description

The invention is in the field of teile measurements.

Known thermistor temerature meters have a linear characteristic in a narrow temperature range.

In the proposed device, in order to obtain a linear characteristic in a wide temperature range, the first thermistor with a linear characteristic zone in the upper part of the temperature range is connected in parallel to a series of chains connected in parallel and consisting of a thermistor with a linear zone in correspondingly lower parts of the temperature range, partially non-opening the characteristic zone of the sensor; its thermistor and in series with the thermistor of the resistor, and all specified ochuvstvitelna soednnena narallelno circuit to a power source having a resistance equal ekvnvaleitnomu sonrotivlepiyu thermosensitive entire chain.

The present invention is based in part on the fact that, by sampling a thermistor with an electrical resistance of a certain size, it is possible to reduce the sensitivity of the thermistor only to 30 OE / o, which is considered ground-state; However, sensitivity is maintained, which determines the aforementioned thermistors.

The present invention aims to create a practical linear characteristic of thermistors and associated with them for measuring the temperature of the dianzonon temperament, nairnmer 1 - 100 ° C; At a temperature of 20 ° C, the tolerance (deviating) is sensitive to the donk of conventional thermistor-sensitive devices. Using the present invention, it is possible to obtain a sensitivity and a linear characteristic with a deviation of 0.2J / o in the bottom zone up to 100 ° C and, therefore, with a deviation of 0.1% in the zone up to 50 ° C.

The sensitivity and speed of measurement by improving the thermal-sensing temperature-sensitive temperature is essential to thermstorns, but the measurement of its measurement is superior to that of conventional single-thermistors.

The proposed device can be used for right-handed measurements of temperature inconsistencies, and both temperatures being compared can be varied — to remove each other at the same speed — nln — from different directions in different half-speed directions.

The device can be made as a separate probe, including two thermistors. which may be exposed to the same ambient temperature, each of which has its own characteristic temperature-resistance, and these characteristics have a defined appearance and correspond to the defined temperature range, and which require accurate readings.

On the ke bar shows the proposed device.

It contains a thermistor Га and aralella, which includes a number of chains containing resistance R.2 of constant value and thermal stator T-2. The thermistor TI is chosen so that it has a line characteristic and the first (highest) temperature range, for example from 60 to 100 ° C. Termnstor T- has a linear zone of characteristics on a more small diagonal zone of temperature, overlapping the highest thermistor 7i; Powermer, Dnapazop linearity of the thermstor T-2 30-70 ° C. The resistance is connected in series to the thermistor 7-2, therefore, the current through the combination "R., - T-2, bypassing the thermistor Gj affects the output output of the zerp. In other words, the output difference between the EIJ and the terminals depends on the total current through 7i and through the sequential circuit, including R-2 and T.2.

The third thermistor T and the third resistance K of a constant value are connected and sequentially in a circuit that is connected in parallel with the thermistor TI and forms another shunt circuit. Thermistor T gives liiiiyo nsmeyenne soirtivlelein at an even lower temperature range, for example from O to 40 ° C. The whole circuit can be continued further by adding a similar shunt branches, each of which includes a complementary series circuit with constant resistance and a thermistor.

The device contains a source of energy 5 and a constant resistance Ri. An output voltage of 0 is applied to the iribor M, and the equivalent resistance of all branches included in the thermosensitive circuit is denoted by Rjf.

The use of a constant voltage source is sometimes more readable than a direct current source. For example, sources of relatively high iotetial can be used to obtain direct current; The same can be achieved with servo systems that regulate the output current. Odpako in both cases, the equipment can be complex and cumbersome.

When using a constant voltage source, such as a nickel-cadmium battery, in combination with a resistance Ri having a constant value depending on the magnitude of Kjf, a simple energy source is obtained. Such a magnitude of the excitation voltage from the source as the signal used may be necessary, for example, in telemetry systems. In addition, in order to obtain maximum clarity of communication or information from the source of measurements, the output voltage Eg should have a linear characteristic with variation

the measured parameter and the whole range of its possible changed.

Equivalent resistance R is determined by adding the conductivities of different shunt circuits: i.e., and, + 7h and Tj. If the energy source is a source of constant current, due to the constant current, it can be excluded from the calculations; applying Ohm’s law, we find that the output naire E (directly proportional to the equivalent resistance to the connected parallel to R. Similarly, if the energy source is a constant source, where Ki forms a voltage separation circuit with U. and isolates the source from the output, the output deflection of the EO will be proportionally proportional to and dependent on the equivalent resistance Rj.

The resistance of PI must be equal to the total resistance of the circuit, consisting of TI T-2 and 2, etc., i.e., equivalent to the resistance of RX at a certain temperature within the system. What exactly this specific temperature should be depends on various factors determined by the specific design of this circuit. Generally speaking, the temperature at which the resistance is equal to the coherence of the temperature-sensitive network is shifted from the middle point of the measurement range in the direction of the upper limit of this range. The magnitude of the temperature displacement at which this equality occurs, depends additionally on the difference in the temperature-resistance characteristics of the thermistors TI p T-2, which enter them into the circuit.

Thermistors T and GO and so on are located close to each other in such a way as to simultaneously respond to the same magnitude of the measured temperature.

Subject invention

Thermistor thermo-sensitive device containing thermistors, and the input of the same temperature effect, located on a common plate and included in the price of the power supply, resistors and indicator, characterized in that, in order to obtain a lii-nary characteristic in a wide temperature range, in the first thermistor In the upper section of the temperature range, with a l-zone, the characteristics are connected in parallel to a row of chains connected in parallel and consisting of a thermstor with a line. ootvetstvenno lower portions of the temperature range partially overlapping the previous liieynuyu zoiu characteristics thermistor and follower soeditsennogo thermistor resistor, and Sun said thermally responsive circuit is connected in parallel with the energy source having an impedance equal to the equivalent resistance of the whole thermosensitive circuit.