JPS61149841A - Viscometer - Google Patents

Abstract

PURPOSE:To calculate a phase difference accurately and to measure viscosity by connecting outputs of phase pulse generating means of two rotation detection plates provided on the rotating shaft and rotor shaft of a motor to a circuit which holds the output of an integration circuit and an up/down counter. CONSTITUTION:When the rotation of a synchronous motor 38 is transmitted to a rotor 50 through a spiral spring 46, the viscous friction torque of liquid to be measured operates to generate a phase delay between rotations of encoders 52 and 54. The encoders 52 and 54 are provided with photointerrupters 64 and 66, and 68 and 70, which outputs start signals SA and SB and phase signals A and B. Both outputs are inputted to the up/down counter to calculate the phase difference of large graduation, which is inputted to a circuit which holds the output of the integration circuit to calculate their ratio, thereby calculating the phase difference of small graduation. Then, both differences are added together to calculate the accurate phase difference between the encoders 52 and 54, thereby measuring the viscosity accurately and continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a viscosity needle, and particularly to a rotational viscometer employing a digital system.

[Conventional technology]

In recent years, the viscosity of liquids has been treated as an important control item for quality control of intermediate and final products and understanding of reaction conditions, and liquid viscosity meters have become effective sensors for monitoring and controlling processes.

This viscosity needle can be broadly classified into capillary viscometer, falling body viscometer, rotational viscometer, vibrational viscometer, and parallel plate viscometer depending on the measurement principle, but especially for non-Newtonian liquids (gelatin, ink, etc.) A rotational viscometer is used to measure the viscosity of.

Here, we will give an overview of the rotary viscometer 2 in the prior art in the first section.
This will be explained based on FIGS. 5 to 18.

In FIG. 15, 4 indicates a synchronous motor. A motor shaft 6 of this synchronous motor 4 is connected to a rotor 12 immersed in the measuring liquid via a spiral spring 8 and a rotor shaft IO. On the motor shaft 6, there is a scale plate 14 on a disc that displays percentages.
However, pointers 16 are fixedly provided on the rotor shaft lO, and in the initial state, the scale plate "0" and the pointers are configured to coincide. On the other hand, on the scale plate 14 "
0'' and below the tip of the pointer 16, bar-shaped protrusions 18 and 20 are provided hanging down (see Fig. 16), and a transmission type photointerrupter 22, 24 between the light emitting and light receiving elements.
20 is configured to pass through. The signal obtained by this transmissive photointerrupter is output to a phase detection circuit 26.The zero phase detection circuit 26 receives signals from the photointerrupters 22 and 24 as shown in FIG. A flip-flop 28 that repeats setting and resetting upon receiving a signal, a pulse oscillation circuit 30 whose frequency can be changed depending on the rotation speed of the electric motor 4, and the oscillation circuit 3.
An AND circuit 32 that takes the logical product of the output of 0 and the output of the flip-flop 28, a counter 34 that counts the number of pulses output from the AND circuit 32, and displays the viscosity according to the number of pulses of the counter 4. The display section 36 includes a display section 36 that displays

In this conventional example, when the electric motor 4 rotates, this rotation is transmitted to the rotor 12 via the spring 8, and the viscous friction torque of the liquid acts on the outer circumference of the rotor 12 immersed in the measuring liquid. Steady rotation occurs when torque and spring force are balanced. At this time, since the magnitude of the torque is proportional to the value read from the declination angle of the pointer 16 fixed to the rotor shaft 10 with the scale plate 14 directly connected to the motor shaft 6, the absolute viscosity is converted to this indicated value. It is found by multiplying by a constant.

That is, during steady rotation, while "0" on the scale plate coincides with the pointer in the initial state, the whole rotates with a certain angle of deviation. Therefore, two signals having a phase difference proportional to the declination angle are obtained once per rotation of the electric motor 4 in the signals detected by the photo-inclination converter. The flip-flop 28 is set by a signal detected by one of the photointerrupters 22, and reset by a signal detected by the other photointerrupter 24. The number of pulses output from the oscillator 30 is counted by a counter 34 at a given time,
This made it possible to determine the angle of deviation, that is, the viscosity (see Figure 18).

[Problem that the invention seeks to solve]

However, in such conventional technology, measurement results can only be obtained once per rotation of the electric motor, so when the user wants to measure viscosity changes while changing the temperature of the measuring liquid, or when the user wants to measure the viscosity change while changing the temperature of the measuring liquid, When a viscosity change occurs due to friction torque, a significant problem arises in that the continuously changing viscosity value cannot be followed and read. Further, in the conventional example described above, the resolution was poor and the measured value was affected by uneven rotation of the drive motor.

The present invention has been made in view of the disadvantages of the prior art, and is a viscometer that can follow the continuously changing viscosity and read the change in viscosity, and can also accurately determine the viscosity. Its purpose is to provide.

[Means for solving problems]

Therefore, in the present invention, in a viscometer that includes a rotor that is introduced into a fluid to be measured and a motor that suspends this rotor via a spring and rotates the rotor integrally, the rotation axis of the motor is A first rotation detection plate is provided on the rotor, and a second rotation detection plate is provided on the rotor shaft of the rotor. The first one generates a phase pulse to detect the phase difference of the second rotation detection plate. a second phase pulse generating means, an integrating circuit that outputs an output for a predetermined period; a hold circuit that holds the output of the integrating circuit based on the output of the second phase pulse generating means; a divider circuit that divides the value held by the hold circuit; an up/down counter that repeats up/down from the output of the second phase pulse generation means; a D/A converter that converts the output of the up/down counter into analog; and an output of the D/A converter and the division circuit. The adder circuit that adds the output of
The purpose of the present invention is to achieve the above objective by adopting a configuration in which the number of points is increased by 1#.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 10.

First, an outline will be explained based on FIGS. 1 to 4.

FIG. 1 is an outline of the main body of a viscometer according to an embodiment of the present invention.

In this figure, 38 indicates a synchronous motor, and an electric shaft 40 of this synchronous motor 38 is connected to a gear eccentric portion 4 including a gear mechanism.
2. Gear shaft 44. Spiral springs 46° are each connected to a rotor 50 immersed in the measurement liquid via a rotor shaft 48,
Rotation of the synchronous motor 38 is transmitted to the rotor 50. The gear shaft 44 is connected to a synchronous motor 38 . An encoder 52 (hereinafter simply referred to as "A phase") directly connected to the gear part 42
The rotor shaft 48 is also equipped with an encoder 54 (hereinafter simply referred to as "B phase") which is directly connected to the rotor 50. Slits 56 and 58 for transmitting start signals SA and SB for determining the phase and slits 60 and 62 for transmitting phase signals A and B for determining the phase are formed, respectively. The start signals SA and SB are detected separately by photointerrupters 64 and 66, and the phase signals A and B are detected by photointerrupters 68 and 70, respectively.

That is, when the rotation of the synchronous motor for three days is transmitted to the rotor 50 via the spiral spring 46, the viscous friction torque of the measurement liquid acts on the outer periphery of the rotor 50, and between the A-phase rotation and the B-phase rotation, A phase lag occurs. Since this phase delay amount is proportional to the viscosity of the liquid, if this phase delay is continuously detected by the photointerrupter 68, 70, it is possible to follow and read even continuously changing viscosity. Become.

By the way, a speed control unit 72 for switching the speed is connected to the synchronous motor 38, and the speed and gear of the synchronous motor 38 are changed according to the designation with the digital switch 74, and the rotation speed desired by the operator is set. It is now possible to obtain it.

On the other hand, the start signals SA, SB and phase signals A, B detected by the photointerrupter 64, 66, 68° 70
is processed by the circuit shown in FIG. 2, and the viscosity is thereby calculated. This FIG. 2 is a block diagram of an electric circuit according to an embodiment of the present invention, and details are shown in FIG. 5 and subsequent figures.

The signals detected by the photointerrupters 64, 66, 68, and 70 are first subjected to a predetermined process in a signal processing circuit 76, and then separated into processes for determining major graduations and minor graduations. Here, if the phase difference between the human phase and the B phase is r4.25J pulses as shown in Fig. 3, the major scale refers to "4" among them, and the small scale refers to ro among these.
, 25J. Specifically, the pulse from the A phase is applied to the up side of the up/down counter (U/D counter) 78, and the pulse from the B phase is applied to the down side of the U/D counter 78, so that the large A scale is required. The pulses counted by the U/D counter 78 are then converted into analog by a D/A converter 80 and output to an analog addition circuit 82. On the other hand, the small scale is A phase and B phase.
This is determined by a phase voltage conversion circuit 84 that converts the phase difference between the two phases into a voltage. This phase voltage conversion circuit 84
is composed of an integrating circuit 86, a dividing ml path 88, and the like. As shown in FIG. 4, the integrating circuit 86 creates a short tooth wave using the A-phase signal, and when the B-phase pulse arrives, it holds the voltage value BH at that time, and when the next A-phase pulse comes, it holds the voltage value BH at that time. When the voltage value AH is reached, the voltage value AH at that time is held. Then, this hold value is output to the division circuit 88, which calculates BH/AH to obtain a small scale, and this value is added to the above-mentioned major scale value in an analog addition circuit. By doing this, a voltage value corresponding to the phase difference can be obtained. This added voltage value is
It is a smooth analog voltage proportional to the amount of phase delay with respect to the phase, and is output as an analog output via the buffer 90, while the multiplier type D/A converter 92. Double integral A/
The signal is digitally outputted on the display section 96 via the D converter 94. The multiplication type D/A converter 92 is an element that multiplies the analog input voltage and the digital input voltage and outputs the result in the form of an analog current. For scaling, the digital input of the multiplication type D/A converter 92 is
Perform the necessary scaling by inputting appropriate coefficients corresponding to various conditions.

The digital input is called up from the memory 98, and the coefficients determined by the "rotation speed", "rotor type", etc. are read out from the memory 98 and used as a multiplication type D/A.
It is input to the digital input of converter 92. and,
The analog signal multiplied by the necessary coefficient is then input to a double integration A/D converter 94 having two integration times for the input voltage and the reference voltage, and is output digitally on the display section 96.

Next, the above content will be explained in more detail.

As shown in FIG. 5, the signal processing circuit 76 includes an A-phase detection means 100, a B-phase detection means 102, a measurement cycle calculation cycle generation means 104 (hereinafter simply referred to as "rMC cycle generation means"), and a denominator signal generation means. It is composed of a means 106 and a molecule signal generating means 108, and serves as a timing signal generating circuit for timing the above-mentioned integrating circuit 86.degree. dividing circuit 88 and the like.

The A-phase detection means 100 includes a phototransistor 100A as a light receiving element of the photointerrupter 64 for detecting the start signal SA, a phototransistor 100B for detecting the phase signal A, a D flip-flop 100C, an AND circuit 100D, etc. It is composed of and,
First, when the start signal SA is input, the Q terminal of the D flip-flop 100C becomes rHJ, and the AND circuit 100C becomes rHJ.
The gate D is opened, and the phase signal A is output to the MC cycle generating means 104, the U side of the U/D counter 78, etc.

On the other hand, the B-phase detection means 102 also includes a phototransistor 10 that detects the start signal SB, almost similarly to the A-phase detection means.
2A, and a phototransistor 102 that detects the phase signal B.
B, D flip-flop 102C, and AND circuit 10
It is composed of 2D etc. However, in this case, since the D terminal of the D flip-flop 102C is connected to the Q terminal of the D flip-flop 100C, the start signal SB is first received from the B phase until the start signal SA comes from the A phase. The gate of the AND circuit 102D will not open even if the current occurs. Therefore, the start signal S
A comes, and then when the start signal SB comes, the gate) 1020 opens, and the phase signal B is output to the molecular signal generating means 108 and the D terminal of the U/D counter 78, etc. via the gate) 102D. be done.

The MC cycle generating means 104 is a 1/2 frequency divider composed of a D flip-flop or the like, and divides the phase signal A by 172 to separate a measurement cycle (M cycle) and a calculation cycle (C cycle). is creating.

During the M cycle, the integrator circuit 86 outputs phase signals A,
This is the time used to hold the voltage values AH and BH at that time when B comes, and the Q output is rH.
The J state is the M cycle. On the other hand, the C cycle transmits the output of the analog addition circuit 82 to the display side,
This is the time used to perform digital display, and when the Q output is in the rLJ state, it is the C cycle. The α terminal of this MC cycle generation means 104 is connected to the differential circuit 11.
6 to the preset terminal 2 of the molecular signal generating means 108
The α terminal is connected to the denominator signal generation means 106, etc., and the α terminal is connected to the D terminal of the numerator signal generation means 108, to the clear terminal of the numerator signal generation means via the AND circuit 110, and to control the charging and discharging of the integrator. analog switch 86
B (see Figure 6).

The numerator signal generating means 108 is composed of a D flip-flop, and is designed to generate a timing signal for holding the output voltage BH of the integrating circuit 86 when the phase signal B arrives. As mentioned above, the preset terminal of this molecular signal generating means 10B has M
The Q output of the C cycle generation means 104 is connected to the MC at the D terminal.
The Q output of the cycle generation means is connected to the clear terminal, and the output of an AND circuit 110 that takes the logical product of the 0 output of the MC cycle generation means and the output of the inverter 114 that inverts the phase signal A is connected to the clock terminal (CK terminal). The output of the AND circuit 102D which outputs the phase signal B and the Q output of the MC cycle generation means 104 are inputted via the diode 112, respectively. Therefore, the molecular signal generating means 108 rises at the rising edge of the M cycle (see Fig. 1O ■), and falls when the phase signal B arrives during the M cycle (holds the voltage value BH in accordance with the timing of this falling edge). Note that the diode 11
Since the clock terminal of the molecule signal generating means 108 is connected to the α terminal of the MC cycle generating means 104 via the MC cycle generating means 104, the clock is not applied even if the phase signal B arrives during the C cycle. ), and when the phase signal B does not arrive, it is configured to be forcibly reset after the C cycle by the output of the AND circuit 110 (see Figure 10 (2) and (2)). This molecular signal generating means 10
The α terminal of 8 is connected to an analog switch 120B shown in FIG. 6, and the signal from this α terminal opens and closes the analog switch 120B, so that the phase difference between the A phase and the B phase is converted into a voltage. It has become.

Further, the denominator signal generating means 106 is constituted by an AND circuit, and generates a timing signal for holding the peak value AH of the slope signal output from the integrating circuit 86. One input terminal of the denominator signal generating means is connected to an inverter 114 for inverting the phase signal A, and the other terminal is connected to the α terminal of the MC cycle generating means. Therefore, the output of the denominator signal generating means 106 rises at the falling edge of the phase signal A during M cycles, and falls at the rising edge (Fig. 10,
(Refer to (2)), the voltage value AH is held in accordance with the timing of this fall. The output terminal of this denominator signal generating means 106 is connected to an analog switch 120A shown in FIG. 6, and the analog switch 120A opens at the falling timing described above to hold the peak of the integrating circuit 86.

On the other hand, as shown in FIG. 6, the phase voltage conversion circuit 84 includes an integrating circuit 86, a time constant selection circuit 118 for selecting the time constant of this integrating circuit, and an integral a hold circuit 12G that holds the output voltage value BH of the circuit 86 and also holds the output voltage value AH of the integrating circuit 86 when the phase signal A arrives;
It is constituted by a division circuit 88.

In the integrating circuit 86, the analog switch 86B provided in parallel with the capacitor 86C is for controlling the charging and discharging of the integrator 86A, and is controlled by the signal from Q of the MC cycle generating means 104 as described above. It is now possible to do so. That is, since the rLJ signal is input during the M cycle, the analog switch 8
6B is open (OPEN) and capacitor 86G
A voltage is charged to the integrator 86A, and the integrator 86A outputs a short tooth wave voltage. On the other hand, since the rHJ signal is input during the C cycle, the analog switch 86B is closed (CLO3
E) and the voltage charged in the capacitor 86C is discharged via the resistor 86D and analog switch 86B, and the output of the integrator 86A becomes zero.

The time constant selection circuit 118 that selects the time constant of the integrating circuit 86 is composed of a digital switch 118A and an analog multiplexer 118B. (not shown) to determine a time constant suitable for the rotation speed.

The hold circuit 120 is an analog switch 12 controlled by the Q output of the molecular signal generating means 108.
0B and the output of the denominator signal generating means 106. : Consists of an lg switch 120A, etc., and a phase signal B.

The analog switches 120B and 120A are set to 0PEN in accordance with the timing of the arrival of the phase fδ, and the output of the integrating circuit 86 at that time is connected to the capacitors 120C and 120.
The hold voltage AH is sent to the divider circuit 88 via buffer circuits 120E and 120F in order to accurately detect the voltage captured at D.

It is configured to send out BH.

The division circuit 88 divides the voltage values BH and AH held by the hold circuit 120 (BH/AH), thereby calculating a small scale, and outputs this result to the analog addition circuit 82. .

Fig. 8 is a timing chart of the circuit shown in Fig. 6, in which the output of the integrating circuit (short tooth wave) is held when phase signal B arrives during the M cycle, and when the M cycle ends. The output of the integrating circuit is held, and the held values are divided in the next C cycle.

By the way, this division circuit 88 divides the A phase and B phase as described above.
In addition to calculating the small scale to find the phase difference with the phase, by dividing the hold value by the numerator and denominator, it is possible to prevent the phenomenon that the pulse interval of the phase signal A is irregular due to uneven rotation of the motor. On the other hand, the small scale can be stabilized. Specifically, as shown in FIG.
Cycle 7MtCt In response to the phenomenon that the pulse interval of the phase signal A becomes longer, the phase signal B also becomes irregular in proportion to this. Therefore, although the hold value captured in each M cycle naturally changes, the division has almost no effect on BHI /AHI qBHt/A HgzakiBHs /AHs and the small scale. On the other hand, if we simply try to process the voltage value BH as a small scale, this phenomenon will cause BH,<BH,
<BH, and it becomes impossible to obtain an accurate value. In addition, by holding the output of the integrating circuit and dividing it to obtain the small scale, there is no need to strictly set the time constant of the integrating circuit as described above, and operability can be improved. can.

On the other hand, the large scale is the U/D counter 78 as shown in FIG.
and an A/D converter that converts the output of this U/D counter into analog.
It is determined by the D converter 80. Then, by adding this analog-converted major scale and the output (small scale) of the aforementioned divider circuit 88 to the analog addition path 82, a smooth analog voltage proportional to the phase difference can be obtained.

Next, the overall operation of the above embodiment will be explained based on FIG. 10.

When the synchronous motor 38 rotates and the start signal SA is detected by the photointerrupter 64, the D flip-flop 100C of the signal processing circuit 76 rises and the AN
The gate of the D circuit 100D is opened and the phase No. 18A is input. This phase signal A is output to the U terminal of the U/D counter 78, and is also output to the MC cycle generation means 104, which generates an M cycle and a C cycle for determining the overall timing of the device. Outputs cycle signal. Then, with the rise of this M cycle, the ζζ molecule increases by one (for example, ■ in the figure). However, it is possible that the signal from the B phase does not come at the initial point of time when the signal is started, so in such a case, the output of the AND circuit 110 is used to generate the molecular signal generating means l.

The output rHJ of 8 is changed to rLJ after the C cycle (■ in the figure). Next, when the start signal SB is input, the D flip-flop 102C rises and the AND circuit 102
Open the gate of D and input the phase signal B. This phase signal B is output to the D terminal of the U/D counter 78, and is also output to the molecular signal generating means 108, which changes the output from rHJ to rLJ in accordance with this timing, for example, as shown in the figure. (2) As a result, the output value (numerator value) of the integrating circuit when the phase signal B is input is set to the hold circuit 12.
Hold by 0. Subsequently, when the M cycle ends, the denominator signal generating means generates a falling signal (for example, ■), whereby the peak (denominator value) of the output of the integrating circuit 86 is held by the hold circuit 120. Then, during the next C cycle, the division circuit 88 performs division to obtain a small scale, and then adds it to the large scale obtained by the U/D counter 78 to obtain the phase difference. Therefore, as mentioned above, the A phase is always the same. Since the signal from the B phase is detected, the viscosity change can be determined by following the continuously changing viscosity.

Next, a second embodiment will be explained based on FIGS. 11 to 13.

FIG. 11 shows a circuit corresponding to the part for determining the large scale in the above embodiment, in which a latch circuit 122 is provided between the U/D counter 78 and the D/A converter 80, and an adder circuit 82 is provided between the U/D counter 78 and the D/A converter 80.
An analog switch 124 is provided at the output. The Q terminal of the molecular signal generation rate stage 108 is connected to the clock terminal that controls the latch circuit, as shown in FIG. 12 (the circuit configuration in FIG. 12 is the same as the signal processing circuit shown in FIG. 5). There is. The output of this 0 terminal is the inverted version of the Q terminal of the molecular signal generating means mentioned above, as shown in FIG.
It is J level. S, the contents of the counter 78 at the time when the phase signal B arrives during the M cycle are latched, and the contents are stored in the D/A converter 80 until the end of the C cycle.
continues to be output. Therefore, the major scale is determined based on the point in time when phase signal B arrives during the M cycle, and the results of the phase signals A and B that arrive during the C cycle are taken into consideration in the next M cycle. On the other hand, the analog switch 12
4 is controlled by an AND circuit 126 shown in FIG. 12, and the AND circuit 126 sends out a signal that rises during the rise time of the phase signal A during the C cycle. Therefore, a value obtained by adding the stable value of the divider circuit and the major scale at the time of latching is outputted to the display side via the analog switch.

According to the second embodiment, in addition to obtaining the same effects as the first embodiment described above, it is possible to continue outputting an accurate phase difference based on the latching time to the display side.

In addition, when there is no need to obtain a more accurate viscosity value, as shown in Fig. 14 (the circuit for detecting the start signal is omitted in Fig. 14), from the A and B phases. The detected phase signal A. B to U/D counter 12
4 to obtain the phase difference and display it on the display circuit 126, it is possible to track and obtain the continuously changing viscosity.

In addition, although the above embodiments have been explained based on a viscometer, the present invention is not limited to this, but can be applied to a device for determining a phase difference,
For example, the main part can be used as is for a torque meter or the like. Further, in the second embodiment, a latch circuit is newly added, but it may be configured with a U/D counter having a latch function.

〔Effect of the invention〕

As described above, according to the present invention, in a viscometer that includes a rotor that is introduced into a fluid to be measured and a motor that suspends this rotor via a spring and rotates the rotor integrally, A first rotation detection plate is provided on the rotation shaft of the motor, and a second rotation detection plate is provided on the rotor shaft of the rotor. The first one generates a phase pulse to detect the phase difference of the second rotation detection plate. a second phase pulse generation means, an integrator circuit that outputs an output for a predetermined period, a hold circuit that holds the output of the integrator circuit using the outputs of the first and second phase pulse generation means, and a a division circuit that performs division of values;
．． an up/down counter that repeats up/down from the output of the second phase pulse generation means; a D/A converter that converts the output of the up/down counter into analog;
Since a configuration is adopted that includes an adding circuit etc. that adds the output of the A converter and the output of the dividing circuit, it is possible to follow the continuously changing viscosity and read the viscosity change, and, It is possible to accurately determine the viscosity even when rotational irregularities occur in the motor, and it is also possible to provide a viscometer with improved resolution. Furthermore, according to the invention of claim 2, it is possible to provide a viscometer that can continue to output accurate viscosity values to the display side.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a viscometer main body according to an embodiment of the present invention;
FIG. 2 is an electrical block diagram of a viscometer according to an embodiment of the present invention, FIGS. 3 and 4 are timing charts for explaining FIG. 2, and FIG. 5 is a detailed diagram of a signal processing circuit. Fig. 6 is a detailed diagram of the phase voltage conversion circuit, Fig. 7 is a detailed diagram of the circuit for determining the major scale, Figs. 8 and 9 are timing charts for explaining Fig. 6, and Fig. 10 is a detailed diagram of the circuit for determining the major scale. 1st
Timing chart for explaining the entire embodiment, 1st
Fig. 1 is a detailed diagram of the circuit for determining the major scale of the viscometer according to the second embodiment, Fig. 12 is a detailed diagram of the signal processing circuit of the viscometer according to the second embodiment, and Fig. 13 is the detailed diagram of the circuit for determining the major scale of the viscometer according to the second embodiment. A timing chart for explaining the entire example, FIG. 14 is a schematic diagram of a viscometer according to another embodiment, FIG. 15 is a schematic diagram of the viscometer main body of the prior art, and FIG. 16 is a part of FIG. 15. An omitted side view, FIG. 17 is an electric circuit diagram of a conventional viscometer, and FIG. 18 is a timing chart of FIG. 17. 3 B------ Synchronous motor as a motor, 50
---------Rotor, 52-----Encoder as first rotation detection plate, 54--Second
encoder as a rotation detection plate, 68--
a photointerrupter as a first phase pulse generating means;
70---Photointerrupter as second phase pulse generating means, 78--Up/down counter, 8 (L------D/A converter, 82--
・-・Addition circuit, 86--・Integrator circuit, 88--
---Divide circuit, 12 (1-------Hold circuit, 122---1--Latch circuit. Patent applicant Tokyo Keiki Co., Ltd. 7' 50 (rotor) Fig. 6 Figure 7: Figure 14 Figure 15 Figure 16

Claims (2)

[Claims] (1) A viscometer comprising a rotor to be introduced into a fluid to be measured, and a motor that suspends this rotor via a spring and drives the rotor to rotate integrally, with a rotor on the rotation axis of the motor. A first rotation detection plate is provided on the rotor shaft of the rotor, and a second rotation detection plate is provided on the rotor shaft of the rotor. a second phase pulse generating means, an integrating circuit that outputs an output for a predetermined period, a hold circuit that holds the output of the integrating circuit according to the output of the first and second phase pulse generating means, and a value held by the hold circuit. an up/down counter that repeats up/down from the outputs of the first and second phase pulse generation means, and a D/A converter that converts the output of the up/down counter into analog; A viscometer comprising: an addition circuit that adds the output of the D/A converter and the output of the division circuit. (2) A viscometer comprising a rotor to be introduced into a fluid to be measured, and a motor that suspends this rotor via a spring and drives the rotor to rotate integrally, wherein a rotor is provided on the rotation axis of the motor. A rotation detection plate is provided on the rotor shaft, and a second rotation detection plate is provided on the rotor shaft.
a phase pulse generating means for detecting the phase difference of the rotation detection plate; an integrating circuit that outputs an output for a predetermined period; and a hold circuit that holds the output of the integrating circuit using the outputs of the first and second phase pulse generating means, respectively. , a division circuit that divides the value held by the hold circuit, an up-down counter that repeats up and down from the outputs of the first and second phase pulse generation means, and an output of the up-down counter. A latch circuit that latches for a predetermined period of time, a D/A converter that converts the output of the latch circuit into analog, and the D/A converter that converts the output of the latch circuit into analog.
An adder circuit that adds the output of the converter and the output of the divider circuit, and an analog switch that transmits the output of the adder circuit to the display side for a predetermined period when the output of the divider circuit becomes constant. A viscometer characterized by: