JPH02145921A - Level controller for liquid - Google Patents

Abstract

PURPOSE:To enable execution of an accurate control for a long time with a simple circuit and free and simple alteration of a working position of the control with the changing of a position of an electrode by using a transistor of a switching means and a thyristor of a gate circuit. CONSTITUTION:First, a water level is too slow for the tip of a first electrode 22 to contact a liquid and with a transistor 6 OFF, a current fails to flow to an electric circuit. Then, with a rise in the wave level, as the tip of the electrode 22 contacts the liquid, the transistor 6 is turned ON to let current flow from a power source 7. A control means detects the water level. As the tip of a second electrode 23 contacts the liquid with further increase in the liquid, a detection signal thereof is sent to a thyristor 9 of a gate circuit to turn ON the circuit and then, a relay 10, which drives a pump 3 of a drain means to discharge the liquid. A self maintaining property of the thyristor 9 allows the continuation of the discharge at the ON state even if the liquid separates from the electrode 23 with a drop in the surface thereof. With further drip in the liquid surface, as the liquid separates from the electrode 22, the thyristor 9 is turned OFF simultaneously with the transistor 6 to stop the pump 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid level control device that detects the level of a liquid and discharges or supplies the liquid.

[Conventional technology]

Conventionally, when detecting the water level of liquids such as water, oil, and other industrial raw materials and fuels and discharging or supplying the liquids, a float 1 is used to detect the liquids as shown in Figure 2. Float 1 operated switch 2 to operate and control pumps and other equipment in response to changes in water level.

However, in this method, the control device itself is large and therefore cannot be freely installed in a small, limited space.

Furthermore, since such devices use mechanical elements.

When used for a long period of time, it has often become difficult to continue accurate water level detection due to rust, wear, and mechanical failure.

[Problem that the invention seeks to solve]

The purpose of the present invention is to improve the conventional drawbacks, to make it easy to install even in a small space by using a simple electric circuit, and to enable the stop interval of the control equipment to be freely and variably set. The present invention provides a liquid level control device that can perform accurate detection even after long-term use.

Another object of the present invention is to provide an economical liquid level control device with low control costs, especially using low voltage driven electrodes.

[Means to solve the problem]

The present invention has the following technical configuration in order to achieve the above object.

That is, a container 20 containing a liquid. Liquid evacuation means 21 connected to the container. Control means 2 for controlling the liquid discharge means
5 and an electrical circuit 27 comprising the control means 25 and optionally a main body control means 26 for controlling the main functions of a main body device (not shown) associated with the container. A first electrode 22 having a detection portion at a position corresponding to a first water level at which water level detection should be started and a second electrode 23 having a detection portion at a position corresponding to a water level higher than the first water level are provided. At the same time, the electric circuit is driven by the water level detection signal of the first electrode via a suitable switch means 6, and the control means is driven by the water level detection signal of the second electrode using a gate circuit 9 having a self-holding property. A liquid level control device configured to be driven through a liquid level control device.

The present invention will be explained in detail below.

The main body device according to the present invention includes a device that directly controls the flow rate of liquid, a device that controls the flow rate and volume of liquid to control the main body device, and all similar devices.

Therefore, as an example of the present invention, FIG. 1 shows a case where the main unit is an air conditioner, the drain receives dew from the air conditioner, detects the water level, and operates a drain pump to discharge the water to a high place. I will explain while referring to it.

A container 20 containing water discharged from the cooling device is provided with a liquid discharge means 21 consisting of a drain pipe 29 connected to the container and a drain pump 3 connected to the drain pipe 29. The electric circuit 27 for controlling the discharge means preferably comprises a DC power source 7 and a control means 25 for controlling the liquid discharge means 21, and the control means 25 is connected to the drain pump 3.
activation.

It is composed of, for example, a relay 10 for controlling stopping.

Furthermore, in the present invention, the electric circuit is connected to another main body control means 2 for controlling starting and stopping of the cooling device which is the main body device.
6 can also be provided in parallel with the control means 25.

The main body control means 26 may be composed of the relay 13, for example.

Partly applicable. The container 20 includes a first electrode 22 having a detection part at a position corresponding to a first water level at which detection of the liquid water level should be started, and a second electrode 22 having a detection part at a position corresponding to a water level higher than the first water level. An electrode 23 is provided.

Such an electrode may have any structure.

Specifically, it may be of a type that energizes when it comes into contact with a liquid such as water, or it may be of a type that optically detects the position of the liquid and transmits a detection signal.

In the present invention, further, a third electrode 2 having a detection portion in the container at a position corresponding to a water level higher than the second water level is provided.
In the present invention, in order to control the driving of the electric circuit 27 by the first electrode 22, an appropriate switch means 6 is provided at an appropriate position of the electric circuit 27. The signals from the electrodes 22 are connected to each other.

The switch means 6 may be of any type as long as the electric circuit can be turned on and off by a gate signal. For example, a transistor 6 as shown in FIG. 1 may be used.

The transistor connects its base to the first transistor via a resistor 14.
The first electrode 22 is connected to one terminal wire 5, and the other terminal wire 4 of the two first electrodes 22 is connected to the electric circuit.

The liquid control means 25 provided in the electric circuit may be of any type as long as it can control starting and stopping of the drainage pump. In this embodiment, the solenoid 2
A relay 10 having 8 is used. The relay 10
has a contact that is always open.

Further, the liquid control means 25 is configured to be turned on and off by a signal from the second electrode 23.

Therefore, the terminal wire 8 of the second electrode 23 is connected to the liquid control means 25 via a resistor 15, and at this time, the liquid control means 25 is driven via a gate circuit 9 having self-retaining properties. Preferably, it is configured as follows.

Although a known flip-flop can be used as the gate circuit 9 having such self-holding property, in this embodiment, a SIRISK is used.

On the other hand, the main body control means 26 provided in the electric circuit is driven by the water level detection signal of the third electrode and is configured to stop the main body device, in this case the cooling device itself. The main body control means may be of any type as long as it can control starting and stopping of the main body; in this embodiment, a relay 13 having a solenoid 29 is used. The relay 13 has contacts that are normally closed.

Further, the main body control means 26 is configured to be turned on and off by a signal from the third electrode 24.

Therefore, the terminal wire 11 of the third electrode 24 is connected to the main body control means 26 via a resistor 16, and in this case, the main body control means 26 is driven via the gate circuit 12 having self-holding property. Preferably, it is configured as follows.

As the gate circuit 12 having such self-holding property, a known flip-flop can be used as described above, but it is preferable to use a SIRISK.

Incidentally, the electric circuit 27 is provided with capacitors 17 and 18, which are provided to prevent malfunctions caused by external noise.

Next, the operation of the present invention will be explained.

In FIG. 1, first, if the liquid level is low and the tip of the first electrode is not in contact with the liquid, the transistor 6
is OFF, so no direct current is supplied to the electrical circuit.

Thereafter, when the level of the liquid rises and the tip of the first electrode comes into contact with the liquid, the transistor 6 is turned on, and current is supplied from the power source 7 to the electric circuit, so that the control means can start detecting the water level. Become.

Next, when the liquid increases further and the tip of the second electrode comes into contact with the liquid, the detection signal is sent to the thyristor 9 via the terminal wire 8, turning on the thyristor and thus turning on the relay 10.
is turned on, thereby driving the pump 3, which is a drainage means, to discharge the liquid.

Even if the liquid level drops due to such draining operation and the tip of the second electrode separates from the liquid level, the present invention uses the thyristor 9, which is a gate circuit with self-retaining properties, so that Cyrisk continues to be ON and the pump 3
continues to drive and continues to discharge liquid.

Then, when the liquid drops further and the tip of the first electrode leaves the liquid level, the transistor 6 goes to 0FFL, which stops power supply to the electric circuit, and at that point the thyristor also turns off and the pump 3 stops driving.

The above embodiment of the present invention is a condensation container 20 for cooling equipment.
This system forms a liquid level detection system and a control circuit to control the liquid in order to discharge it to another location using pump 3, but for some reason the bomb etc. does not operate and the water level rises abnormally. In this case, when the surface of the liquid comes into contact with the tip of the third electrode, the detection signal is sent to the thyristor 12 via the terminal wire 11, and the thyristor is ONL, and therefore the relay 13 of the main body control means 26 is constantly activated. When the closed contact is OFF, all functions of the cooling device can be stopped and the liquid can be prevented from overflowing.

Note that in this embodiment, the resistor 14 provided in the electric circuit
, 15 and 16 are provided in order to supply an appropriate signal voltage for the cyrisk and to prevent a large current from flowing through the cyrisk or the transistor even if the detection electrodes come into contact with each other.

[For production]

The present invention uses the conductivity of the liquid to control the water level of the liquid, and by using silice and transistors, accurate control can be performed over a long period of time with a simple circuit, and the control circuit The operating position of can be changed freely and easily by changing the position of each electrode.

Furthermore, according to the present invention, since the liquid level control device can be formed in a small size, its application areas are greatly expanded compared to conventional devices.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing a control circuit of a liquid level control device according to the present invention. FIG. 2 is a schematic diagram showing a water level control device in a conventional liquid water level control device. 1... Float, 2... Switch 3...
・Pump. 4.5, 8, 8°, 11.11'... terminal wire. 6... Transistor, 7... Power supply. 9.12... Thyristor. 10.13... Relay 20... Container. 21... Drainage means 22... First electrode. 23... Second electrode. 24... 25... 26... 27... 28, 2 Third electrode. control means. Body control means. Electrical circuit for control. 9...Solenoid.

Claims (1)

[Claims] 1. Consists of a container containing a liquid, a liquid discharge means connected to the container, a control means for controlling the liquid discharge means, and an electric circuit 1 including the control means. , the container includes a first electrode having a detection part at a position corresponding to a first water level at which water level detection should be started, and a second electrode having a detection part at a position corresponding to a water level higher than the first water level. In addition, the electric circuit is driven by the water level detection signal of the first electrode via an appropriate switch means, and the control means is a gate having a self-holding property by the water level detection signal of the second electrode. 2. The liquid level control device according to claim 1, wherein the liquid level control device is configured to be driven via a circuit, and the switch means for driving the electric circuit is a transistor. Liquid level control device 4 according to claim 1, characterized in that the control device 3, the self-retaining gate circuit for driving the control means is a thyristor, the electric circuit further associated with the container. A main body control means for controlling the main functions of the main body device is provided, and the main body control means includes a third electrode provided in the container and having a detection portion at a position corresponding to a water level higher than the second water level. 4. The liquid level control device according to claim 1, wherein the liquid level control device is configured to be driven by a water level detection signal.