SU892707A1

SU892707A1 - Multichannel resistance increment-to-time interval converter

Info

Publication number: SU892707A1
Application number: SU792830611A
Authority: SU
Inventors: Лев Николаевич Латышев; Владимир Александрович Чудаев
Original assignee: Уфимский Нефтяной Институт
Priority date: 1979-10-18
Filing date: 1979-10-18
Publication date: 1981-12-23

Description

(54) МНОГОКАНАЛЬНЫЙ ПРЕОБРАЗОВАТЕЛЬ ПРИРАЩЕНИЯ СОПРОТИВЛЕНИЯ В ИНТЕРВАЛ ВРЕМЕНИ(54) MULTICHANNEL TRANSFORMER FOR INCREASING RESISTANCE IN TIME INTERVAL

II

Изобретение относитс к измерительной технике и автоматике и может найти применение при дистанционном измерении малых приращений сопротивлений или неэлектрических величин, функционально св saHHbix с приращением сопротивлени , например температуры, давлени и т.д.The invention relates to measurement technology and automation and can be used in the remote measurement of small increments of resistance or non-electrical quantities, functionally with saHHbix with an increment of resistance, such as temperature, pressure, etc.

Известен преобразователь дл тензорезисторов , содержащий источник питани , тензорезисторный датчик, масштабные усилители, коммутирующие, элементы, интегратор, блоки управлени 1 .A known transducer for strain gauges, containing a power source, a strain gauge sensor, large-scale amplifiers, switching elements, an integrator, control units 1.

Однако при дистанционном измерении на результат преобразовани известного преобразовател значительное вли ние оказывает сопротивление линий св зи, соедин н дих датчик с преобразователем.However, during remote measurement, the result of converting a known converter is significantly affected by the resistance of the communication lines connected to the sensor with the converter.

Наиболее близким по технической сущности к предлагаемому вл етс многоканальный преобразователь приращени сопротивлени в интервал времени , содержащий резистивные датчики , потенциальные выходы которых через линии св зи соединены с первыми входами каналов, выход которого соеди нен с первым входом интегратора, выход которого через коммутатор подключен к первому входу триггера, делитель напр жени , источник питани , разр дный переключатель, резисторы и блок управлени , подключенный к The closest in technical essence to the present invention is a multichannel impedance increment converter in a time interval containing resistive sensors, the potential outputs of which are connected to the first channel inputs through the communication lines, the output of which is connected to the first integrator input, the output of which is connected to the first trigger input, voltage divider, power supply, bit switch, resistors and a control unit connected to

10 управл ющим входам коммутатора каналов разр дного ключа и второму входу триггера{2310 control inputs of the switch of the bit switch and the second trigger input {23

Недостатком известного преобразовател вл етс мала точность преобг A disadvantage of the known converter is low accuracy of conversion.

tS разовани за счет вли ни остаточных параметров коммутатора каналов и неполной компенсации сопротивлени проводов линий св зи.tS of development due to the influence of the residual parameters of the channel switch and incomplete compensation of the resistance of the wires of the communication lines.

Цель изобретени - повышение точ20 ности преобразовани .The purpose of the invention is to improve the accuracy of the conversion.

Claims

The goal is achieved by the fact that in a multichannel impedance increment converter in a time interval containing resistive sensors, I potential terminals of which communication lines are connected to the first inputs of a channel switch, the output of which is connected to the first integrator input, the output of which through the comparator is connected to the first input trigger, voltage divider, power supply, bit switch, resistors and control unit connected to the control inputs of the channel switch, bit switch and the second the trigger output of the first current outputs of the resistive sensors through the communication lines are connected to a power source and voltage divider, the midpoint of which is connected to the first input of the gating switch, the output of which is connected to the second integrator input, the second input of the gating switch is connected to the common bus, the second current terminals of the resistive sensors through, the communication lines are connected to the second inputs of the channel switch and connected to the common bus through resistors. The drawing shows a block diagram of the converter. The converter contains N resistive half-bridges consisting of resistive sensors 1 (R) and resistors 2 (Rrt) equal to the initial resistance of the sensor, H three-wire communication lines, divider 4. voltage, and the divider resistance equal to each other, switch 5 channels with keys 6 and 7, power supply 8, integrator 9 with greater 4 INPUT 11M resistance, comparator 10, trigger 11, control unit 12, bit switch 13. The converter on each of the polling in dx channels occurs in two steps. When polling, for example, the first channel, the switch 6 of the channel switch 5 is closed, and 7 is open, the discharge switch I3 is connected to the midpoint of the voltage divider. With the voltage unbalance of the bridge formed by sensor 1, resistor 2 and voltage divider 4, which, taking into account the resistance R of the communication line 3, residual resistance R | keys 6,7 and Rg7Kd. Equal to Q - E 2 (de E voltage of power supply source 8; increment of measured resistance.: v constant resistance connected in series with measured; V input resistance of integrator. At the end of the first cycle, the voltage at the integrator output is equal to the equilibrium time interval of the first cycle ; t is the time constant of the integrator 9 In the second cycle, the control unit 12 switches the bit switch 13 to the common bus, the switch 6 of the channel switch 5 is opened and the switch 7 is closed. As a result, the input to the integrator 9 will be on the resistor 2 in II.. 2Yd -2Ro-AR The integrator 9 is completely discharged 9. The final conversion function of the transducer is a linear function, and for a sufficiently large input resistance of the integrator, the residual resistance of the switching elements and cop The lines of communication will have almost no effect on the measurement result, since they are included in the potential wires. Resistance of the communication line, included in the current wires, is excluded from the final conversion function provided the same of their changes. Multi-channel resistance increment converter in time interval, containing resistive sensors, the potential outputs of which are connected to the first inputs of the channel switch, the output of which is connected to the first input of the integrator, the output of which through the comparator is connected to the first input of the trigger, voltage divider , power supply, bit switch, resistors and control unit connected to the control inputs of the channel switch, bit switch and the second input A rigger that is connected with the fact that, in order to improve the accuracy of the conversion, the first current outputs of the resistive sensors are connected to the power source and voltage divider, the middle point of which is connected to the first input of the discharge switch 7. "L, the output of which is connected to the second input of the integrator, the second input of the bit switch is connected to the common bus, the second current terminals of the resistive sensors are connected to the second inputs of the channel switch and via resistors through common lines Noah. Sources of information taken into account in the examination 1. Instrumentation and control systems, 1976, No., p. 30-31. (

2. USSR author's certificate No. 603119, cl. H 03 K 13/20, 1978 (prototype).