SU1583772A1 - Code pressure transducer - Google Patents

Abstract

The invention relates to instrumentation engineering and makes it possible to simplify a code pressure sensor. For this, along with gauge 1, arrow 2, on the end of which magnet 3 is fixed, reed switches 4 mounted in ring frame 5, counter 23, elements 2И 12-16 and 2 OR 19, 20, the code pressure sensor contains constant resistors 6 , generators 7, 8, formers 9, 10 pulses, unit for setting 11 time intervals, one-shot 17, 18, frequency divider 21 into two and element NOT 22. Depending on whether one or two reed switches are closed, the movement of arrow 2 will be converted into one or two frequencies of the output signals of the generators 7, 8. These signals are converted into a code that It is loaded into counter 23. 4 Il.

Description

UNION OF SOVIET SOCIALIST REPUBLICS

„., SU <„, 1583772 A1 <505 G 01 L 19/12

STATE COMMITTEE

BY INVENTIONS AND DISCOVERIES

PRI ΓΚΗΤ USSR

DESCRIPTION OF THE INVENTION |

i E, AND & LIOTE.G.D

TO AUTHOR'S CERTIFICATE

(21) 4408034 / 24-10 (22) 11.04.88 (46) 07.08.90. Bull. No. 29 (72) N.A. Samovarov and Yu.V. Petrokansky (53) 531.787 (088.8) (56) USSR Copyright Certificate No. 1397758, cl. G 01 L 19/12, 1986.

(54) CODE PRESSURE SENSOR (57) The invention relates to instrumentation and allows to simplify a code pressure sensor. For this, along with a manometer 1 with an arrow 2, at the end of which a magnet 3 is fixed, reed switches 4 installed in an annular frame 5, a counter 23, elements 2I 12-16 and 2 OR 19, 20, a pressure code encoder contains constant resistors 6, generators 7, 8, 9.10 pulse shapers, 11 time interval adjuster, single vibrators 17. 18, frequency divider 21 into two and element NOT 22. Depending on whether one or two reed switches are closed, moving arrow 2 is converted to one or two frequencies output signals of generators 7.8. These signals are converted into code, which is loaded into the counter 23. 4 ill.

Figz

The invention relates to instrumentation and can be used in telemetry systems for measuring pressure of aggressive and toxic environments, in particular for measuring gas pressure in mine workings, in the chemical industry, in hard-to-reach and life-threatening places,

The aim of the invention is to simplify the code pressure sensor.

Figure 1 presents the structural diagram of the pressure sensor; figure 2 is a timing diagram of his work; Fig. 3 is a structural diagram of a time slider; figure 4 is a diagram of an RC generator.

The code pressure sensor contains a pressure gauge 1 (Fig. 1) with an arrow 2, a magnet 3 mounted on the end of the arrow, a row of reed switches 4o, 4ι ..... 4p installed in an annular frame 5, constant resistors 6o, 6ι .... .6 _P , two

RC generators 7 and 8, two pulse shapers 9 and 10, 11 time interval adjuster, five elements 2I 12 - 16, two single vibrators 17 and 18 with restart, two elements OR 19 and 20, frequency divider 21 into two, element NOT 22 and counter 23,

The first outputs of the even reed switches are connected and connected to the first input of the first RC generator 7. The first outputs of the odd reed switches are similarly connected to the first input of the RC generator 8. The second outputs of the even and odd reed switches are connected through the corresponding resistors to the second inputs of the generators 7 and 8, respectively . The outputs of the generators 7 and 8 through the pulse shapers 9 and 10 are connected to the start inputs of the corresponding single-shots 17 and 18 and to the first inputs of the elements & 2I 12 and 13, respectively. The second inputs of the elements 2I 12 and 13 are connected respectively to the first and second outputs of the master 11 time intervals. The outputs of the elements 2I 12 and 13 are connected to the inputs of the element 2 OR 19, the output of which is connected to the first inputs of the elements 2I 15 and 16. The outputs of the single vibrators 17 and 18 are connected to the inputs of the element 2I 14, the output of which is directly connected to the second input of the element 2I 15 and through the element NOT 22 is connected to the second input of the element 2I 16. The output of the element 2I 15 through the divider 21, and the output of the element 2I 16 is directly connected to the inputs of the element 2 OR 20, the output of which is connected to the input of the counter 23. The third output of the setter 11 is connected to the reset inputs of the counter 23 and the frequency divider 21.

The conductivities of the resistors 6 in each group are selected from the calculation so that when switching the reed switches 4, the frequency at the output of each of the generators 7 and 8 changes by a known constant value. If, for example, the frequency increment is taken to be 2 kHz, then the generator 7, when even resistors 6 ° are connected to its input. 62 ..... 6p should give a sequence of frequencies 0, 4, 8, 12 ... kHz, and the generator 8 when connecting resistors 6ι, 63 ..... 6p-1 - a sequence of frequencies

2, 6, 10 kHz.

When resistors are disconnected by reed switches, pulse generation in both generators should stop. Reed switch 4o and resistor 6o are designed to control the zero position of the needle gauge. Since the zero frequency corresponds to this position, it is advisable to choose the conductivity of the resistor 6o to ensure that the output signal with a minimum frequency of about several tens of hertz is obtained.

Code pressure sensor works as follows.

When moving arrow 2, magnet 3 closes one reed switch if the middle line of the arrow passes through the reed switch, or two reed switches if the middle line passes between these reed switches. In the first case, one of the resistors will be connected to the input of only one of the generators 7 and 8, from the output of which a signal of a certain frequency will be taken. In the second case, resistors will be connected to the inputs of both generators 7 and 8 and, therefore, two signals with fixed frequencies will be removed from the outputs of the generators.

The controller 11 time intervals periodically gives three signals: the reset pulse of the divider 21 and the counter 23, then the first rectangular pulse to the input of element 2I 12 to measure the frequency of the generator 7, and after its end, the second rectangular pulse to the input of element 2I 13 to measure the frequency of the generator 8 (figure 2). Consider the coding process for the specific case when arrow 2 occupies a middle position between the reed switches 4d and 4z. In this position, resistors 62 and 6z will be connected to the inputs of the generators 7 and 8, respectively. which will correspond to the output frequencies of 4 kHz for the generator 7 and 6 kHz for the generator 8.

Let us take the duration of the pulses issued by the master 11 equal to 1 ms, then when polling the generator 7, four pulses will come from the output of element 2I 12, and when polling the generator 8, six pulses will come from the output of element 2I 13. Since both single vibrators will be started, element 2I will be closed, and element 214 15 will be open. Therefore, ten pulses from the output of element 2IL14 19 will pass through element 214 15 to the input of the frequency divider 21 into two, from the output of which through element 214L14 20 five pulses will arrive at the input of counter 23 and counter 23 will register the count 5. If arrow 2 stops opposite the reed switch 4z . then the generator 7 will stop supplying pulses, and from the generator 8 will continue to receive a signal with a frequency of 6 kHz. In this case, the output of element 214 14 will have a low voltage level and, therefore, element 2I 15 will be closed, and element 2Y 16 will be open. Six pulses from the output of element 214 Л И 19 will pass through elements 2I 16, 2 OR 20 to the input of counter 23 and countdown 6 will be fixed. Similarly, if arrow 2 is located opposite the reed switch 4d, then count 4 will be fixed in counter 23.

The controller 11 time intervals can be performed according to the structural diagram (Fig.Z), which shows the pulse generator 24, the frequency divider 25, single vibrators 26 and 27 and the pulse shaper 28; ca along the trailing edge of the output pulse of the single-shot 26. Generators 7 and 8 can be made according to the scheme (figure 4) of the relaxation generator.

When implementing the described device, reed switches, resistors and generators 7 and 8 are placed in the pressure gauge housing 1. The pulse shapers 9 and 10 are located on the receiving side of the communication line, they serve to restore the steepness of the pulse fronts.

In the described device there are no such complex microcircuits as a switch and a reversible counter of a known device of the same purpose, moreover, the implementation of the device requires fewer microcircuits.

Thus, the technical and economic advantages of the described device consist in its simplification and in providing the possibility of using it in the composition of industrial telemetry equipment.

Claims (2)

Claim A code pressure sensor containing a manometer with an arrow, a permanent magnet fixed at the end of the arrow, reed switches mounted around the perimeter of the pressure gauge, five elements 214, two 2 OR elements, and a counter, characterized in that. to simplify, it is equipped with two groups of constant resistors, two RC generators, a timing unit, two single vibrators with a restart, a frequency divider into two, two pulse shapers and an element NOT, and through the reed switches even in the direction of the arrow, to the input of the first RC the resistors of the first group are connected, through the odd reed switches to the input of the second RC generator, the resistors of the second group are connected, the outputs of the first and second RC generators, respectively, through the first and second formers pulse in connected with the starting inputs of the corresponding single-vibrators and with the first inputs of the first and second elements 214, respectively, to the second inputs of which the first and second outputs of the time interval master are connected, the outputs of the first and second elements 214 are connected to the corresponding inputs of the first OR element 2, the output of which is connected to the first the inputs of the third and fourth elements 214, the outputs of the first and second single vibrators are connected to the corresponding inputs of the fifth element 214, the output of which is connected to the second input of the third element 2I and with the input of the element NOT, the output of which is connected to the second input of the fourth element 214, the output of which is connected to the first input of the second element 2IL14, the second input of which is connected through the frequency divider by two to the output of the third element 214, the output of the second element 2OR is connected to the input counter, and the third output of the time slider is connected to the inputs of the reset to zero state of the counter and the frequency divider by two. element outputs ... J ish sho Fig.z SHL 11JLJLJLJL ... ILJL £ XJL „„ Л1ШОШ1_ I Count 6 Countdown4 Cl ...... .....- s ·· * FIG. 2 count 5