Two Tank Auto On Off Controller, Certification : CE Certified

Our organization has gained reputation as a Manufacturer and Supplier of Two Tank Auto On/Off Controller. Two Tank Auto On/Off Controller efficiently controls sump as well as overhead tank. Two Tank Auto On/Off Controller is specially designed for application such as hostels, apartments, hospitals, etc, where controlling the water tank is very essential. The specialty of this circuit is that it controls upper as well as lowers tanks. Motor becomes on when upper tank is empty and lower tank is at predetermined low level. In addition, it becomes off when water level in the upper tank reaches to high level or it is full. The sensors for lower and upper tank are shown in circuit diagram.
About the Circuit :

• The circuit uses IC1, which consists of four AND gates. The Low and High sensors of upper tanks are connected to one of the inputs of two AND gates in IC1. The low- level sensor of lower tank is connected to one of the input of NAND gate in IC4 and IC3. IC2, which is wired as bistable multi vibrator gets triggered according to the logic level present at the threshold input pin6 and trigger pin2. IC3, which is a four input AND gate gets triggered when all its input are logic high which in turn drives transistor T1. In addition, there is an audible warning when lower tank is below the low level.
• The basic operation of the circuit is as follows : Suppose lower tank is at low level and upper tank is empty. In this case, output of IC1 at pin4 is low. As a result, IC2 is triggered and gives logic high pulse at output pin3. As all the inputs of IC3 are high, it gives output high. Transistor T1 conducts and relay becomes on. LED D2 glows, which shows that motor is on. It remains on as long as water level in upper tank reaches to High level.
• When upper tank reaches to High level, the output of IC1 at pin4 becomes high; IC2 gets reset and generate low pulse at pin3. As one of the input of IC3 receives logic low value, its output becomes low. T1 turns off and relay connected to the collector of T1 becomes off. In addition, LED D2 goes off and it remains off until upper tank becomes empty.
• Also, there is a provision for audible warning. When lower tank is below low level, the output of IC3 is low and motor is off as this water is not good for drinking. At the same time IC4 gives high output. As a result, Transistor T2 conducts and buzzer connected at the collector terminal raises alarm, which gives an indication that the lower tank is empty. Also LED D3 glows, which gives visual indication.