Liquid level detection device with double-path output function

Abstract

The utility model provides a liquid level detection device with a double-path output function, which comprises an insulating shell, a cavity with a downward opening is formed in the insulating shell, and a vent hole is formed in the middle of the side wall of the cavity; a first liquid level detection terminal and a second liquid level detection terminal are fixedly arranged in the cavity, the first liquid level detection terminal and the second liquid level detection terminal are vertically arranged electrode bars, the lower ends of the electrode bars correspond to the ventilation opening, and the lower end heads of the first liquid level detection terminal and the second liquid level detection terminal are flush with each other; the first liquid level detection terminal and the second liquid level detection terminal are arranged in the insulating shell and are matched with the ventilation opening in the insulating shell, so that liquid can enter the insulating shell and make contact with the electrode bar, the first liquid level detection terminal and the second liquid level detection terminal are conducted, the liquid level detection accuracy can be effectively improved, and the liquid level detection efficiency is improved. And the corrosion of dirty liquid to the electrode bar is prevented, and the adaptability of the electrode bar is improved.

Description

Technical Field

[0001] This utility model relates to liquid level signal detection technology, specifically to a liquid level detection device with dual-channel output function. Background Technology

[0002] Currently, liquid level detection methods are divided into passive detection methods based on reed switches and active detection methods based on infrared light or ultrasound. Reed switch-based methods rely on a magnetic float to control the switch's conduction; if the float becomes stuck, the method will malfunction. Infrared light or ultrasound-based methods have more limitations regarding the liquid being measured and will not function properly in contaminated environments. Utility Model Content

[0003] In view of the problems in the prior art, this utility model provides a liquid level detection device with dual output function, which aims to improve the accuracy and adaptability of liquid level detection.

[0004] A liquid level detection device with dual-output function includes an insulating housing, a downward-opening chamber formed inside the insulating housing, and a vent in the middle of the side wall of the chamber. A first liquid level detection terminal and a second liquid level detection terminal are fixedly installed in the chamber. Both the first liquid level detection terminal and the second liquid level detection terminal are vertically arranged electrode rods, and the lower ends of the electrode rods are aligned with the vent. The lower ends of the first liquid level detection terminal and the second liquid level detection terminal are flush with each other.

[0005] Furthermore, the insulating shell is made of plastic.

[0006] Furthermore, the insulating shell has a cylindrical structure with an open lower end and a closed upper end, with the vent located at its lower end.

[0007] Furthermore, the first liquid level detection terminal and the second liquid level detection terminal are electrically connected to signal terminal 1 and signal terminal 2 of the signal processing circuit, respectively. The signal processing circuit includes a voltage divider circuit, a signal generation circuit, and a liquid level signal output circuit. Signal terminal 1, signal terminal 2, and the signal generation circuit are all electrically connected to the voltage divider circuit and are used to regulate the voltage in the voltage divider circuit. The liquid level signal output circuit is used to adjust its output level according to the voltage in the voltage divider circuit.

[0008] Further, the voltage divider circuit includes a resistor R1. One end of resistor R1 is connected to the first power supply voltage, and the other end of resistor R1 is connected to the second power supply voltage via resistors R7 and R8. Both the first and second power supply voltages are positive voltages and of the same magnitude. The common terminal of resistors R1 and R7 is signal terminal 1 and is connected to the first input terminal of the liquid level signal output circuit. The common terminal of resistors R1 and R7 is also grounded via resistor R4. The common terminal of resistors R7 and R8 is connected to the second input terminal of the liquid level signal output circuit. One output branch of the signal generation circuit is connected to one end of capacitor C9, and the other end of capacitor C9 serves as signal terminal 2. The other branch is connected to the anode of diode D3. The cathode of diode D3 is connected to the first input terminal of the liquid level signal output circuit. The cathode of diode D3 is also connected to signal terminal 1 via capacitor C8.

[0009] Furthermore, the liquid level signal output circuit is a comparator U2B. The IN2+ pin of the comparator U2B is connected to signal terminal 1 via resistor R6. The common terminal of resistors R7 and R8 is connected to the IN2- pin of the comparator U2B. The OUT2 pin of the comparator U2B serves as the output of the liquid level signal output circuit.

[0010] Furthermore, the signal generation circuit includes a comparator U2A. The IN1+ pin of the comparator U2A is connected to signal terminal 1 via resistor R3. One branch of the common terminal of resistors R3 and R4 is connected to signal terminal 1, and the other branch is connected to the IN1- pin of the comparator U2A via capacitor C7. The IN1- pin of the comparator U2A is also connected to its OUT1 pin via resistor R5. The IN1+ pin of the comparator U2A is also connected to its OUT1 pin via resistor R2. The OUT1 pin of the comparator U2A is the output terminal of the signal generation circuit.

[0011] The beneficial effects of this utility model are as follows: by setting the first liquid level detection terminal and the second liquid level detection terminal inside the insulating housing, and cooperating with the vent on the insulating housing, liquid can enter the insulating housing and come into contact with the electrode rod, thereby connecting the first liquid level detection terminal and the second liquid level detection terminal, which can effectively improve the accuracy of liquid level detection and prevent the corrosion of the electrode rod by dirty liquid, thus improving the adaptability of this utility model. Attached Figure Description

[0012] Figure 1 This is a perspective view of the insulating shell and electrode rod mounting structure in this utility model;

[0013] Figure 2 This is a circuit diagram of the signal processing circuit in this utility model. Detailed Implementation

[0014] The present invention will now be described in detail with reference to the accompanying drawings. Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The directional terms such as left, center, right, top, and bottom in the embodiments of the present invention are only relative concepts or referenced to the normal use state of the product, and should not be considered restrictive.

[0015] A liquid level detection device with dual output function, such as Figure 1 As shown, the device includes an insulating housing 1, preferably made of plastic. A downward-opening chamber is formed within the insulating housing 1, and a vent 11 is provided in the middle of the side wall of the chamber. The insulating housing 1 has a cylindrical structure, with an open lower end and a closed upper end. The vent 11 is located near its lower end. A first liquid level detection terminal and a second liquid level detection terminal are fixedly installed within the chamber. Both the first and second liquid level detection terminals are vertically arranged electrode rods 2, with their lower ends corresponding to the vent 11. The lower ends of both the first and second liquid level detection terminals are flush with each other. Both the first and second liquid level detection terminals are housed within the insulating housing 1. Under the action of the vent 11, the liquid being measured cannot cover the entire electrode rod 2; only the head of the electrode rod 2 can contact the liquid being measured, thus avoiding corrosion of the electrode rod 2 by dirty liquid. Under the action of the insulating housing 1, the liquid level within the insulating housing 1 is relatively stable and not easily affected by air bubbles on the liquid surface.

[0016] The first liquid level detection terminal and the second liquid level detection terminal are electrically connected to signal terminal 1 and signal terminal 2 of the signal processing circuit, respectively. Figure 2As shown, the signal processing circuit includes a voltage divider circuit, a signal generation circuit, and a liquid level signal output circuit. Signal terminal 1, signal terminal 2, and the signal generation circuit are all electrically connected to the voltage divider circuit and used to regulate the voltage in the voltage divider circuit. The liquid level signal output circuit is used to adjust its output level according to the voltage in the voltage divider circuit. The voltage divider circuit includes a resistor R1. One end of resistor R1 is connected to the first power supply voltage, and the other end of resistor R1 is connected to the second power supply voltage via resistors R7 and R8 in sequence. Both the first and second power supply voltages are 24V positive voltages and of the same magnitude. The common terminal of resistors R1 and R7 is signal terminal 1 and is connected to the first input terminal of the liquid level signal output circuit. The common terminal of resistors R1 and R7 is also grounded via resistor R4. The common terminal of resistors R7 and R8 is connected to the second input terminal of the liquid level signal output circuit. One branch of the output terminal of the signal generation circuit is connected to... One end of capacitor C9 is connected, and the other end of capacitor C9 serves as signal terminal 2. The other branch is connected to the positive terminal of diode D3. The negative terminal of diode D3 is connected to the first input terminal of the liquid level signal output circuit. The negative terminal of diode D3 is also connected to signal terminal 1 via capacitor C8. The liquid level signal output circuit is comparator U2B. The IN2+ pin of comparator U2B is connected to signal terminal 1 via resistor R6. The common terminal of resistors R7 and R8 is connected to the IN2- pin of comparator U2B. The OUT2 pin of comparator U2B serves as the output of the liquid level signal output circuit. When the liquid level is lower than the first and second liquid level detection terminals, the first and second liquid level detection terminals are disconnected. At this time, the output signal (NetLabel1) of the signal generation circuit charges capacitor C8 through diode D3, and capacitor C8 will be charged to the power supply voltage. According to the resistor voltage divider formula, the voltage at the common terminal of resistors R1 and R7 is greater than the voltage at the common terminal of resistors R7 and R8, and comparator U2B outputs a high level. When the liquid level rises and the first and second liquid level detection terminals are connected through the liquid, the output signal (NetLabel1) of the signal generation circuit charges capacitor C9. The positive terminal of diode D3 has a fixed voltage value, which is approximately equal to the voltage at signal terminal 1. At this time, the output signal (NetLabel1) of the signal generation circuit cannot charge capacitor C8. According to the resistor voltage divider formula, the voltage at the common terminal of resistors R1 and R7 is less than the voltage at the common terminal of resistors R7 and R8, and comparator U2B outputs a low level.

[0017] In addition, to simplify the circuit, the signal generation circuit includes comparator U2A. The IN1+ pin of comparator U2A is connected to signal terminal 1 via resistor R3. One branch of the common terminal of resistors R3 and R4 is connected to signal terminal 1, and the other branch is connected to the IN1- pin of comparator U2A via capacitor C7. The IN1- pin of comparator U2A is also connected to its OUT1 pin via resistor R5. The IN1+ pin of comparator U2A is also connected to its OUT1 pin via resistor R2. The OUT1 pin of comparator U2A is the output terminal of the signal generation circuit.

[0018] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A liquid level detection device with dual-output function, characterized in that: The application relates to an insulating shell which comprises a downwardly-opened cavity, a ventilation opening is arranged in the middle of the cavity side wall, a first liquid level detection terminal and a second liquid level detection terminal are fixedly arranged in the cavity, the first liquid level detection terminal and the second liquid level detection terminal are both vertically arranged electrode rods, the lower ends of the electrode rods correspond to the ventilation opening, and the lower end heads of the first liquid level detection terminal and the second liquid level detection terminal are arranged in a flush manner.

2. The liquid level detection device having a dual output function according to claim 1, characterized in that: The insulating shell is made of plastic.

3. The liquid level detecting device having a dual output function according to claim 1, characterized in that: The insulating shell is in a cylindrical structure, the lower end of the insulating shell is arranged in an open manner, the upper end of the insulating shell is arranged in a closed manner, and the ventilation opening is arranged near the lower end port.

4. The liquid level detecting device having a dual output function according to claim 1, characterized in that: The first liquid level detection terminal and the second liquid level detection terminal are electrically connected with signal end 1 and signal end 2 of a signal processing circuit, the signal processing circuit comprises a voltage division circuit, a signal generation circuit and a liquid level signal output circuit, signal end 1, signal end 2 and the signal generation circuit are electrically connected with the voltage division circuit and are used for regulating the voltage in the voltage division circuit, and the liquid level signal output circuit is used for adjusting the output level according to the voltage in the voltage division circuit.

5. The liquid level detection device having a dual output function according to claim 4, characterized in that: The voltage division circuit comprises a resistor R1, one end of the resistor R1 is connected with a first power voltage, the other end of the resistor R1 is connected with a second power voltage through a resistor R7 and a resistor R8 in sequence, the first power voltage and the second power voltage are both positive voltages and have the same size, the common end of the resistor R1 and the resistor R7 is signal end 1 and is connected with a first input end of the liquid level signal output circuit, the common end of the resistor R1 and the resistor R7 is further connected with the ground through a resistor R4, the common end of the resistor R7 and the resistor R8 is connected with a second input end of the liquid level signal output circuit, an output end branch of the signal generation circuit is connected with one end of a capacitor C9, the other end of the capacitor C9 is signal end 2, the other branch is connected with the positive electrode of a diode D3, the negative electrode of the diode D3 is connected with the first input end of the liquid level signal output circuit, and the negative electrode of the diode D3 is further connected with signal end 1 through a capacitor C8.

6. The liquid level detection device having a dual output function according to claim 5, characterized in that: The liquid level signal output circuit is a comparator U2B, the IN2+ pin of the comparator U2B is connected with signal end 1 through a resistor R6, the common end of the resistor R7 and the resistor R8 is connected with the IN2- pin of the comparator U2B, and the OUT2 pin of the comparator U2B is the output of the liquid level signal output circuit.

7. The liquid level detection device having a dual output function according to claim 5, characterized in that: The signal generation circuit comprises a comparator U2A, the IN1+ pin of the comparator U2A is connected with signal end 1 through a resistor R3, the common end of the resistor R3 and the resistor R4 is connected with signal end 1, one branch of the common end is connected with the IN1- pin of the comparator U2A through a capacitor C7, the other branch is connected with the IN1- pin of the comparator U2A, the IN1- pin of the comparator U2A is further connected with the OUT1 pin of the comparator U2A through a resistor R5, the IN1+ pin of the comparator U2A is further connected with the OUT1 pin of the comparator U2A through a resistor R2, and the OUT1 pin of the comparator U2A is the output end of the signal generation circuit.

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