Water level indicator

Water Level Indicator

Description

This is the circuit diagram of a simple corrosion free water level indicator for home and industries. In fact the the level of any conductive non corrosive liquids can be measured using this circuit. The circuit is based on 5 transistor switches. Each transistor is switched on to drive the corresponding LED , when its base is supplied with current through the water through the electrode probes.

One electrode probe is (F) with 6V AC is placed at the bottom of tank. Next probes are placed step by step above the bottom probe. When water is rising the base of each transistor gets electrical connection to 6V AC through water and the corresponding probe. Which in turn makes the transistors conduct to glow LED and indicate the level of water. The ends of probes are connected to corresponding points in the circuit as shown in circuit diagram.Insulated Aluminum wires with end insulation removed will do for the probe. Arrange the probes in order on a PVC pipe according to the depth and immerse it in the tank.AC voltage is use to prevent electrolysis at the probes. So this setup will last really long. I guarantee at least a 2 years of maintenance free operation. That’s what I got and is still going.

Components

T1 – T5 BC 548 or 2N2222 Transistors

R1-R5 2.2K 1/4 W Resistors

R6-R10 22K 1/4 W Resistors

D1 – D5 LED’s ( color your choice)

Notes:

Use a transformer with 6V 500 mA output for power supply. Do not use a rectifier! we need pure AC. Use good quality insulated Aluminum wire for probes. If Aluminum wires are not available try Steel or Tin.Copper is the worst. Try the circuit first on a bread board and if not working properly, make adjustments with the resistance values. This is often needed because conductivity of water changes slightly from place to place. The type number of the transistors used here are not critical and any small signal NPN transistor will do the job. Few other suitable type numbers are BC546, BC107, PN2222, BC337, BF494, ZTX300, BEL187 etc. The circuit can be enclosed in a plastic box with holes for revealing the LEDs .

Water Level Indicator Circuit Diagram and Sensor Arrangement.

 

Water Level Indicator

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Automatic Water Level Controller

Water-level controllers are common nowadays. The one described here is built around timer NE555 and inverter buffer CMOS IC CD4049. It uses readily-available, low-cost components, and is easy to build and install on the over-head tank (OHT) to prevent wastage of water. The circuit works off a 12V battery or 230V AC mains using a 12V adaptor. The three sensors built from non-corrosive metal are fitted to the OHT as shown in Fig. 2 and connected to the circuit (Fig. 1) at appropriate terminals.

Automatic Water-Level Controller Circuit Diagram

Power supply terminal Vcc is at the bottom of the tank, sensor terminal L is just above the bottom of the tank and sensor terminal H is at the top of the tank. After you have properly installed the sensors in the OHT and connected the power supply, the circuit is ready to use. Since Vcc terminal is at the bottom of the tank, when the water level falls below sensor L, timer IC2 is triggered at pin 2 via inverters N1 and N2 and its output goes high. As a result, the output of timer IC2 goes high. Relay RL1 energises and the motor starts filling water in the tank.

Automatic Water-Level Controller

The motor remains ‘on’ even when the water level crosses sensor L. As water in the tank rises to touch sensor H, timer IC2 is retriggered at pin 6 via inverters N3 and N4 and as a result, its output goes low. The relay de-energises and the motor stops filling water in the tank. The motor remains ‘off’ even when the water level falls below sensor H. As water is consumed and its level falls below sensor L, the motor restarts. Thereafter, the cycle repeats. You can also manually start and stop the motor using switch S1.

• Source
• ElectronicsForU

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Numeric Water Level Indicator

Most water-level indicators for water tanks are based upon the number of LEDs that glow to indicate the corresponding level of water in the container. Here we present a digital version of the water-level indicator.    It uses a 7-segment display to show the water level in numeric form from0 to 9. The circuit works off 5V regulated power supply. It is built around priority encoder IC 74HC147 (IC1), BCD-to-7-segment decoder IC CD4511 (IC2), 7-segment display LTS543 (DIS1) and a few discrete components. Due to high input impedance, IC1 senses water in the container from its nine input terminals. The inputs are connected to +5V via 560-kilo-ohm resistors.

Numeric Water-Level Indicator Circuit diagram 

The ground terminal of the sensor must be kept at the bottom of the container (tank). IC 74HC147 has nine active-low inputs and converts the active input into active-low BCD output. The input L-9 has the highest priority. The outputs of IC1 (A, B, C and D) are fed to IC2 via transistors T1 through T4. This logic inverter is used to convert the active-low output of IC1 into active-high for IC2. The BCD code received by IC2 is shown on 7-segment display LTS543. Resistors R18 through R24 limit the current through the display.

When the tank is empty, all the inputs of IC1 remain high. As a result, its output also remains high, making all the inputs of IC2 low. Display LTS543 at this stage shows 0, which means the tank is empty. Similarly, when the water level reaches L-1 position, the display shows 1, and when the water level reaches L-8 position, the display shows 8. Finally, when the tank is full, all the inputs of IC1 become low and its output goes low to make all the inputs of IC2 high. Display LTS543 now shows 9, which means the tank is full. Assemble the circuit on a general-purpose PCB and enclose in a box. Mount 7-segment LTS543 on the front panel of the box. For sensors L-1 though L-9 and ground, use corrosion-free conductive-metal (stainless-steel) strips.

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ULN2004 Water Level Indicator

This ULN2004 electronic project circuit diagram design is a very simple water level indicator circuit project . This ULN2004 water level indicator circuit is very simple and require few external electronic parts .

ULN2004 is a high voltage, high current darlington arrays that contain seven open collector darlington pairs with common emitters . Each channel rated at 500mA and can withstand peak currents of 600mA.

 ULN2004 Water Level Indicator Circuit Diagram

As the water level rise in the tank , it comes in contact with probes P1 through P7 and thereby makes pins 7 trough 1 high sequentially . The corresponding output pins 10 trough 16 go low one after other and LED1 through LED7 will light up . When water comes in contact with the last probe P7 , the buzzer connected to the last pin 16 will sound .

This electronic circuit project must be powered from a fixed output DC voltage that will provide an output voltage between 9 and 12 volts .

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Transistor Water Sensor Alarm

This water sensor alarm circuit diagram is designed using common electronic components. Thewater sensor alarm circuit may operate an active buzzer, to make a sound when is reached a certain level of water.

Transistor Water Sensor Alarm Circuit Diagram

Because water sensor and control circuit for buzzer are located on the same printed circuit board, indicator, together with 9 V battery and buzzer can be mounted in a compact case.

When water reaches the sensor, the base of T1 is connected to the positive supply terminal. Therefore, T1 and T2 are open, so that buzzer BZ1, will be activated. Sensitivity reduction of the circuit can be done by increasing the value of R2.

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