JPH0579882A - Multi-electrode water level detector - Google Patents

Abstract

PURPOSE:To obtain a water level detecting part of a multi-electrode water level detector for which a considerably small constant number of leading wires to be taken out in the air is sufficient even when the number of water level electrodes is increased in order to measure the high water level with high accuracy. CONSTITUTION:Water level electrodes 30-39 are disposed in a depthwise direction within a hollow cylinder of an insulator 1. Transistors 20-29 are connected to the corresponding water level electrodes 30-39. Flip-flops 10-19 for driving the transistors 20-29 are connected in series in the order of the depth, thereby to constitute a shift register. A sequential circuit constructed as above is put in the water along with a common electrode 2 facing the water level electrodes, whereby a water level detecting part is obtained. Three control lines and two electrode source lines common to the whole of the flip-flips are drawn into the air from the water level detecting part and connected to a water level detector control part WLSC, a shift register resetting output part SHRR, a shift register setting output part SHRS, a pulse generating part POSC, a pulse counter part PCOT, a digital water level indicating part DWLM, an electrode current detecting part CDET, a current sensor CSES, and a direct current source part DCPW.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a multi-electrode water level detector used for measuring water levels in dam lakes, water reservoirs, rivers, water level channels and the like.

[0002]

2. Description of the Related Art A conventional water level detector for this purpose is of a type called a multi-electrode water level detector having a large number of electrodes in a water level detector. For example, as disclosed in Japanese Patent Publication No. 43-2142 and Japanese Patent Publication No. 45-14692, a plurality of electrodes (hereinafter referred to as water level electrodes) attached to an insulating rod is installed in water as a water level detection unit. Then, one lead wire is drawn out into the air for each electrode from this, another one electrode (hereinafter, common electrode) is provided in water, and there is a difference in electric resistance between each water level electrode and the common electrode. Utilizing this, the water level is detected by knowing which electrode is submerged in water.

[0003]

In the conventional water level detector of this type, one wire is drawn into the air for each water level electrode. Therefore, if the number of electrodes is increased in order to improve the water level measurement accuracy. However, there is a problem that the number of conducting wires drawn out in the air increases by that number, and the number becomes enormous in high-accuracy measurement at high water level.

The present invention solves this problem and, even if the number of water level electrodes is increased, the number of conducting wires drawn into the air is set to an extremely small number of constant wires, and the number of water level electrodes is increased without considering the increase in the number of conducting wires. It is an object of the present invention to provide a water level detection unit that can increase the water level measurement accuracy easily.

[0005]

In order to achieve the above object, in the multi-electrode water level detector of the present invention, an insulator to which a large number of water level electrodes are attached is formed in a hollow cylindrical shape with a closed tip. , This is used as a water level detection part, the tip part is submerged downward, the opening of the hollow cylinder at the other end is exposed above the water surface, and one switch is installed for each water level electrode inside the hollow cylinder. The collector of each transistor is connected, the emitter of the transistor is connected to one power supply line common to all the water level electrodes, and one flip-flop circuit (FF) is provided for each transistor. Is connected to the base of each transistor. And these FF
Are connected in series in the order of depth so that they can be used as a progressive circuit constituting a shift register, and three control lines (shift register-reset signal line, shift register) common to all of these FFs are connected. -Set signal line, pulse signal line), and a common electrode power source line + side facing all the water level electrodes + side, electrode power source line for common electrode-one side is provided, and only a total of five of them are provided. It was pulled out in the air. If the inside of the hollow cylinder of the insulator is watertightly and airtightly filled with synthetic resin or the like after installation of these transistors and FFs and wiring, the water level detection unit becomes highly reliable.

[0006]

[Operation] The water level detector as described above is installed in water,
By controlling only the power supply line and the control line drawn into the air, the water level can be detected by drawing a very small number of constant lines into the air regardless of the measured water level and the measurement accuracy.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A multi-electrode water level detector of the present invention will be described with reference to the accompanying drawings with reference to the drawings. In FIG. 1, a large number of water level electrodes 30 to 39 are provided on an insulator 1 of a hollow cylinder having a closed end. I will explain in the case of 10) attached in a watertight structure,
One switch transistor for each water level electrode
20 to 29 collectors are connected. The emitter is connected in parallel to the electrode power line + side 3 and this is connected to the current sensor outside the cylinder −.
Connect to the + terminal of the DC power supply unit DCPW outside the cylinder through CSES. Further, each of the transistors-20 to 29 is provided with one FF10 to 19 for driving the base.
The output of F is connected to the base of each transistor-20-29.

The connection around each FF10 to 19 is shown in FIG.
This will be described in detail with reference to FIG. 2 which is a partially enlarged view of the same. An external shift register-reset output unit SHRR
Shift register-reset line 7 from FF10 to 1
9 are connected to all reset terminals R. The shift register-set signal line 8 from the shift register-set output section SHRS is connected to the input set terminal D of the FF10, and the output terminal Q of the FF10 is the base of the transistor-20 and the FF11 of the next stage. It is connected to the input terminal D. Similarly to this, each of the subsequent FFs 11 to 1
9 and transistors 21 to 29, the output terminal Q of the FF in the previous stage is sequentially connected to the input terminal D of the FF in the next stage and the base of each transistor.

A common electrode 2 is attached to the insulator 1 at a position opposed to each of the water level electrodes 30 to 39, and is connected to the-terminal of the DC power supply unit DCPW via the electrode power supply line-side 4 from this. There is. The water level detector control unit WLSC for controlling the entire water level detector has a built-in timer circuit, and is supplied with power from the control power supply line + side 5 and the control power supply line − side 6 from the DC power supply unit DCPW. Water level detector controller WLSC
Shifts the digital water level indicating section DWLM through the digital water level indicating section control line 43, the pulse oscillating section POSC through the pulse oscillating section control line 41, the shift register-reset output section SHRR through the shift register-reset output section control line 46. Shift register-set output unit SHRS through register-set output unit control line 47
, Respectively. Also, pulse counter-PCO
From T, the count value of the pulse corresponding to the current water surface 48 is sent to the digital water level indicator DWLM through the count value transmission line 40 to display the current water level. Water level electrode 30
The current flowing from ~ 39 to the common electrode 2 is the current sensor-CS.
The ES detects this, sends a current signal to the electrode current detection unit CDET through the current sensor-signal line 44, and the electrode current detection unit CDET checks this. That is, if the air between the water level electrodes 30 to 39 and the common electrode 2 is air, the electric resistance is large and no current flows, and if the water is water, the electric resistance is small and a current flows. The water level electrodes 30 to 39 are sequentially checked one by one to see if they are in the air or in water. If no current flows, the current sensor-CSES does not send a current signal,
The electrode current detection unit CDET also does not send a current detection signal to the water level detector control unit WLSC, and the water level electrode is considered to be in the air. When current flows, current sensor-CSES
Is an electrode current detector C through the electrode current detector output line 44.
A current signal is sent to the DET, and the electrode current detection unit CDET sends the water level detector control unit WL through the electrode current detection unit output line 45.
Sends a current detection signal to the SC to notify that the water surface has been detected.

In the above description, the water level detector controller WLS
C, shift register-reset output unit SHRR, shift register-set output unit SHRS, pulse oscillation unit POS
C, pulse counter-PCOT, digital water level indicator DWLM, electrode current detector CDET, current sensor-C
Although SES, DC power supply unit DCPW and the like are shown as circuit blocks having individual functions, this is for convenience of description, and some or all of them are a microcomputer or hardware logic circuit. Obviously it can be replaced by

Next, how the water level is detected in this embodiment will be described. It is assumed that the current water surface 48 is between the water level electrodes 34 and 35 as shown in FIG.
This water level detector is a timer of the water level detector controller WLSC-
The water level is detected at a predetermined sampling time, for example, every 1 second by the control signal sent from the. The order will be described below. At the time of first activation, in order to initialize the system, the water level detector control unit WLSC issues a reset command to the shift register-reset output unit SHRR through the shift register-reset output unit control line 46, and the shift register-reset output unit. SHRR sends a reset signal from the shift register-reset signal line 7 to each FF10-1.
9 to reset the input / output of each FF10-19.
At the same time, the water level detector control unit WLSC also sends a signal to the digital water level instructing unit DWLM through the digital water level instructing unit control line 43 to set the instructed value to 0. Further, a signal is sent to the pulse oscillating unit control line 41 to stop the pulse oscillating unit POSC, and the pulse counter-unit PCOT is reset by the signal passing through the pulse signal output line 42. This completes the initialization and then moves on to water level detection. First, the water level detector control unit WLSC operates the shift register-set output unit control line 47.
Shift register-set output section SHR
The S is instructed to output the set, and the shift register-set output unit SHRS outputs the set to the shift register-set signal line 8. Thus, the input is set to the input terminal D of the first stage FF10. Next, the water level detector control unit WLSC commands the pulse oscillating unit POSC to oscillate one pulse by a signal passing through the pulse oscillating unit control line 41. Pulse oscillator PO
The SC outputs one pulse to the pulse output signal line 42, the pulse counter-PCOT counts one, and then outputs one pulse to the pulse signal line 9. This pulse is the first stage FF1
When input to the pulse input terminal C of 0, the FF10 sends a set signal from the output terminal Q to the input terminal D of the FF11 in the next stage, and at the same time, outputs the set signal to the base of the transistor-20 to make the transistor-20 conductive and direct current. An attempt is made to pass a current from the water level electrode 30 to the common electrode 2 from the + side of the power source unit DCPW through the electrode power line + side 3, but during this period, the current is air, so the resistance value is high, so no current flows. The sensor-CSES does not detect the current and the electrode current detection unit CDE
Since T does not send a current detection signal, the water level detector control unit WL
The SC determines that the water surface 48 has not reached the water level electrode 30 after waiting for a predetermined time required for current detection. The second pulse transmission is the pulse transmission unit POS.
When a command is issued to C and a pulse is output in the same manner as described above, the pulse counter-PCOT counts 1 and the FF 11 receives the pulse input and sends a set signal to the next FF 12 and turns on the transistor 21 to turn on the level electrode. Whether the space between 31 and the common electrode 2 is water or air is checked. Since this is also air, the same process as above is repeated again. In this way, the water level detection electrodes 32, 33, 34, and 35 are sequentially checked for water or air between the common electrodes 2, but the water level electrode 35 detects water for the first time. Now, explaining the operation of the water level electrode 35,
Current from the + side of the DC power supply unit DCPW through the current sensor -CSES from the electrode power supply line + side 3 to the transistor -25, the water level electrode 35, water, the common electrode 2, the electrode power supply line-side 4, the-side current of the DC power supply unit DCPW A circuit is formed and a current flows, the current sensor-CSES detects this and sends a current signal to the electrode current detection unit CDET, and the electrode current detection unit CDE
T sends a water detection signal to the water level detector control unit WLSC via the electrode current detection unit output line 45. Then, the water level detector control unit WLSC causes the digital water level instructing unit DWLM to hold the current count value and the current water level value corresponding thereto to instruct the current water level, and then, the pulse transmitting unit POSC, the pulse counter-unit PCOT, the shift register. -Reset output unit SHRR, shift register-Clear all current values of set output unit SHRS, electrode current detection unit CDET-Stop the output and put it in the dormant state. Water level detector controller WL
The SC repeats such an operation at each of the above-mentioned predetermined sampling times, updates the water surface 48 if there is a change, and causes the digital water level indicator DWLM to store the current count value and the current water level corresponding thereto, Display it. If a preset action to be performed according to various water levels is stored internally, it is performed. Since the operation of the water level detection described above is all performed by the electronic circuit, it ends in a very short time, so the sampling time can be set to a considerably short time if necessary. Of course, there is no limit for long hours, so
It can respond to rapid changes in water level. Further, in the above description, the sampling time is a fixed fixed time, but the water level can be detected by setting some other factor as a sampling starting point without setting the time (cycle).

[0012]

As described above, according to the present invention, in the multi-electrode water level detector, the water level detecting portion provided in the water is provided with the progressive scanning circuit which constitutes the shift register in the order of depth, and the water level is detected. By controlling this from outside, even if the number of electrodes increases, the number of conducting wires drawn into the air becomes a very small constant number of wires, so that a highly accurate water level detector can be easily and easily manufactured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view and block diagram of a multi-electrode water level detector.

FIG. 2 is an enlarged view of part A in FIG.

[Explanation of symbols]

1 Insulator 2 Common electrode 3 Electrode power supply line + side 4 Electrode power supply line-side 5 Control power supply line + side 6 Control power supply line-side 7 Shift register-reset signal line 8 Shift register-set signal line 9 Pulse signal line 10, 11, 12, 13, 14, 15, 16, 17, 1
8, 19 Flip-flops (FF) 20, 21, 22, 23, 24, 25, 26, 27, 2
8, 29 transistors-30, 31, 32, 33, 34, 35, 36, 37, 3
8, 39 Water level electrode 40 Count value transmission line 41 Pulse oscillation part control line 42 Pulse output signal line 43 Digital water level indicator control line 44 Current sensor-signal line 45 Electrode current detection part output line 46 Shift register-reset output part control line 47 Shift register-set output control line 48 Water surface

Claims (1)

[Claims] 1. A water level detection unit that is placed in water and has a progressive scanning circuit that constitutes a shift register in the order of depth, and has a large number of water levels in the depth direction of the water level detection unit. When the electrodes are arranged, a common electrode is installed so as to face the many water level electrodes, and the value of the current flowing between each water level electrode and the common electrode with the water level electrode as an input terminal exceeds a predetermined threshold value. A multi-electrode water level detector characterized in that the shift register is driven depending on whether or not the water level is detected by the output of the shift register.