Low-cost five-section LED water level display circuit

Abstract

The utility model discloses a low-cost five-section LED water level display circuit which comprises a water level sampling circuit, four comparator circuits, four voltage division circuits and five LED drive circuits which are connected with one another. The LED drive circuit comprises four green LED groups and a red LED group, and the red LED group is provided with a phase inverting circuit to realize state phase inversion with the fourth green LED group. The utility model has the following advantages and effects: 1, the number of lighted green light emitting tubes and the water level can be set to be in a linear relationship, which is simple and clear; 2, elements used by the circuit all adopt conventional general specifications, so that the cost is extremely low; 3, pure hard wire circuit realization is realized, and software support is not needed; and 4, a universal water level sensor signal in the market can be directly matched, namely a corresponding resistance signal is output along with the change of the water level.

Description

Technical Field

[0001] The utility model relates to the technical field of alarm circuits, in particular to a low-cost five-segment LED water level display circuit. Background Art

[0002] The market for modified vehicles is relatively large at present, and some vehicles are equipped with water tanks as needed, requiring a device to display the current water level.

[0003] Since most users have limited modification costs, how to reduce costs and maintain the stability and reliability of the device has become a new direction for improvement. Utility Model Content

[0004] The utility model aims to provide a low-cost five-segment LED circuit for displaying water level.

[0005] The above technical purpose of the utility model is achieved through the following technical scheme: a low-cost five-segment LED water level display circuit, including an interconnected water level sampling circuit, four comparator circuits, four voltage divider circuits and five LED drive circuits; the LED drive circuit includes four green LED groups and one red LED group, and the red LED group is provided with an inverting circuit to achieve inversion of the state with the fourth green LED group.

[0006] It is further configured as follows: the water level sampling circuit includes a power supply end, a resistor R7 is connected to the power supply end, and a water level sensor RF is connected to the resistor R7; a capacitor C1 is connected between the resistor R7 and the water level sensor RF, the other end of the water level sensor RF is connected to the other end of the capacitor C1, and the other end of the capacitor C1 is grounded at the same time; a VF output end of a sampling voltage signal is provided between the resistor R7 and the water level sensor RF.

[0007] It is further configured as follows: the voltage divider circuit includes a power supply, four voltage divider groups are connected in parallel to the power supply, the voltage divider groups each include two resistors connected in series, the latter resistor is grounded, and the latter resistors are connected in parallel with a capacitor; a V-in output terminal is connected between the two resistors of each voltage divider group.

[0008] It is further configured as follows: the comparator circuit adopts four-way comparator LM324, each way includes a comparator, the input end of the comparator is respectively connected to the VF output end and the V-in output end, and the V-out output end of the comparator is respectively connected to the LED driving circuit.

[0009] It is further configured as follows: the green LED groups all include a power supply, a resistor is connected to the power supply, a green LED is connected to the resistor, a transistor is connected in series to the green LED, the base terminal of the transistor is connected to the V-out output terminal, and the emitter terminal is grounded; the red LED group includes a power supply, a resistor R5 and a resistor R6 are respectively arranged on the power supply, an LED5 is arranged on the resistor R5, a transistor Q5 is arranged on the LED5, a transistor Q6 is arranged on the resistor R6, the base of the transistor Q5 is connected to the collector terminal of the transistor Q6, and the base of the transistor Q6 is connected to V-out4; the base of the transistor Q5 is also provided with a capacitor C6, and the capacitor C6 is grounded.

[0010] In summary, the utility model has the following beneficial effects:

[0011] 1. The number of green light-emitting tubes lit and the water level can be set to a linear relationship, which is simple and clear;

[0012] 2. The components used in the circuit are all of conventional general specifications, with extremely low cost;

[0013] 3. Pure hard-wire circuit implementation, no software support required;

[0014] 4. It can directly match the universal water level sensor signal on the market, that is, it can output the corresponding resistance signal as the water level changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the schematic diagram of the water level sampling circuit;

[0016] Figure 2 is a schematic diagram of a comparator circuit;

[0017] Figure 3 is a schematic diagram of a voltage divider circuit;

[0018] Figure 4 Schematic diagram of LED driving circuit. DETAILED DESCRIPTION

[0019] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0020] A low-cost five-segment LED water level display circuit comprises a water level sampling circuit, four comparator circuits, four voltage divider circuits and five LED drive circuits which are connected to each other.

[0021] The water level sampling circuit includes a 5V power supply terminal, a resistor R7 is connected to the power supply terminal, a water level sensor RF is connected to the resistor R7, and the water level sensor RF outputs different resistances as the water level changes. A capacitor C1 is connected between the resistor R7 and the water level sensor RF, and the other end of the water level sensor RF is connected to the other end of the capacitor C1, and the other end of the capacitor C1 is grounded at the same time. Among them, a VF output terminal for sampling voltage signal is set between the resistor R7 and the water level sensor RF.

[0022] The voltage divider circuit includes a 5V power supply, and four voltage dividers are connected in parallel to the power supply, and the voltage dividers include the same 5V power supply. The first voltage divider is connected in series with a resistor R8 and a resistor R9, the resistor R9 is grounded, a capacitor C2 is connected in parallel to the resistor R9, and a V-in1 output terminal is extended between the resistor R8 and the resistor R9; the second voltage divider is connected in series with a resistor R10 and a resistor R11, the resistor R11 is grounded, a capacitor C3 is connected in parallel to the resistor R11, and a V-in2 output terminal is extended between the resistor R10 and the resistor R11; the third voltage divider is connected in series with a resistor R12 and a resistor R13, the resistor R13 is grounded, a capacitor C4 is connected in parallel to the resistor R13, and a V-in3 output terminal is extended between the resistor R12 and the resistor R13; the fourth voltage divider is connected in series with a resistor R14 and a resistor R15, the resistor R15 is grounded, a capacitor C5 is connected in parallel to the resistor R15, and a V-in4 output terminal is extended between the resistor R14 and the resistor R15.

[0023] The comparator circuit uses a four-way comparator LM324, each of which includes a comparator. The comparator is powered by a 5V power supply. One of the input ends of the four comparators is connected to the signal of the same VF output end, and the other input end is respectively connected to the signals of the V-in1 output end, the V-in2 output end, the V-in3 output end and the V-in4 output end. The output ends of the four comparators correspond to the output V-out1 output end, the V-out2 output end, the V-out3 output end and the V-out4 output end respectively.

[0024] The LED driving circuit includes a first green LED group, a second green LED group, a third green LED group, a fourth green LED group and a red LED group. The first green LED group includes a 5V power supply, a resistor R1 is connected to the 5V power supply, LED1 is connected in series to the resistor R1, a collector of a transistor Q1 is provided on LED1, the emitter of the transistor Q1 is grounded, the base of the transistor Q1 is connected to a first resistor, the first resistor is connected to the V-out1 output terminal, and a second resistor is provided between the base and the emitter of the transistor Q1. The first resistor and the second resistor are as follows: Figure 4The internal resistance of the transistor group shown is the same as the following. The second green LED group includes a 5V power supply, a resistor R1 is connected to the 5V power supply, LED2 is connected in series to the resistor R2, the collector of the transistor Q2 is arranged on LED2, the emitter of the transistor Q1 is grounded, the base of the transistor Q2 is connected to the first resistor, the first resistor is connected to the output terminal V-out2, and a second resistor is arranged between the base and the emitter of the transistor Q1. The third green LED group includes a 5V power supply, a resistor R3 is connected to the 5V power supply, LED3 is connected in series to the resistor R3, the collector of the transistor Q3 is arranged on LED3, the emitter of the transistor Q3 is grounded, the base of the transistor Q3 is connected to the first resistor, the first resistor is connected to the output terminal V-out3, and a second resistor is arranged between the base and the emitter of the transistor Q3. The fourth green LED group includes a 5V power supply, a resistor R4 is connected to the 5V power supply, an LED4 is connected in series to the resistor R4, a collector of a transistor Q4 is provided on LED4, the emitter of the transistor Q4 is grounded, the base of the transistor Q4 is connected to a first resistor, the first resistor is connected to the V-out4 output terminal, and a second resistor is provided between the base and the emitter of the transistor Q4.

[0025] The red LED group includes a 5V power supply, and the 5V power supply is connected to resistors R5 and R6 respectively. The resistor R5 is connected in series with LED5 that emits red light, and the LED5 is connected to the collector of transistor Q5, and the base of transistor Q5 is provided with a first resistor, and the first resistor is connected to the emitter of transistor Q5 and then grounded; the resistor R6 is connected to the collector of transistor Q6, and the base of transistor Q6 is provided with a first resistor, and the first resistor is connected to the V-out output terminal; a capacitor C6 is provided between the first resistor where the transistor Q5 is located and the collector of the transistor Q6, and the other end of the capacitor C6 is grounded.

[0026] In the present application, the corresponding water level range of each green light-emitting tube is determined by the resistance ratio of the corresponding voltage divider circuit. The corresponding water level range of LED1 (green) is determined by the ratio of R9 / R8; the corresponding water level range of LED2 (green) is determined by the ratio of R11 / R10; the corresponding water level range of LED3 (green) is determined by the ratio of R13 / R12; the corresponding water level range of LED4 (green) is determined by the ratio of R15 / R14; when LED4 is also off, LED5 (red) is lit.

[0027] The functions implemented by this circuit are as follows: when the water level is between 100% and 80%, four green LEDs are lit, namely LED1 / LED2 / LED3 / LED4; when the water level is between 80% and 60%, three green LEDs are lit, namely LED2 / LED3 / LED4; when the water level is between 60% and 40%, two green LEDs are lit, namely LED3 / LED4; when the water level is between 40% and 20%, one green LED is lit, namely LED4; when the water level is lower than 20%, a red LED alarm is lit, namely LED5, indicating that the water tank needs to be added with water.

[0028] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A low-cost five-segment LED water level display circuit, characterized by: It includes an interconnected water level sampling circuit, four comparator circuits, four voltage divider circuits and five LED drive circuits; the LED drive circuit includes four green LED groups and one red LED group, and the red LED group is provided with an inverting circuit to achieve inversion with the fourth green LED group.

2. A low-cost five-segment LED water level display circuit according to claim 1, characterized in that: The water level sampling circuit includes a power supply end, a resistor R7 connected to the power supply end, and a water level sensor RF connected to the resistor R7; a capacitor C1 is connected between the resistor R7 and the water level sensor RF, and the other end of the water level sensor RF is connected to the other end of the capacitor C1, and the other end of the capacitor C1 is grounded at the same time; a VF output end of a sampling voltage signal is provided between the resistor R7 and the water level sensor RF.

3. A low-cost five-segment LED water level display circuit according to claim 2, characterized in that: The voltage divider circuit includes a power supply, and four voltage divider groups are connected in parallel to the power supply. The voltage divider groups each include two resistors connected in series, the latter resistor is grounded, and the latter resistors are connected in parallel with a capacitor; a V-in output terminal is connected between the two resistors of each voltage divider group.

4. A low-cost five-segment LED water level display circuit according to claim 3, characterized in that: The comparator circuit adopts four-way comparator LM324, each way includes a comparator, the input end of the comparator is respectively connected to the VF output end and the V-in output end, and the V-out output end of the comparator is respectively connected to the LED driving circuit.

5. A low-cost five-segment LED water level display circuit according to claim 4, characterized in that: The green LED groups all include a power supply, a resistor is connected to the power supply, a green LED is connected to the resistor, a transistor is connected in series to the green LED, the base terminal of the transistor is connected to the V-out output terminal, and the emitter terminal is grounded; the red LED group includes a power supply, a resistor R5 and a resistor R6 are respectively arranged on the power supply, an LED5 is arranged on the resistor R5, a transistor Q5 is arranged on the LED5, a transistor Q6 is arranged on the resistor R6, the base of the transistor Q5 is connected to the collector terminal of the transistor Q6, and the base of the transistor Q6 is connected to V-out4; the base of the transistor Q5 is also provided with a capacitor C6, and the capacitor C6 is grounded.

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