water tank controller

[antus]

I need a pic based wlc circuit which has dry run protection. plz suggest me a Web page link.

 

[milan.rajik]

It is very easy. Use eTape Standard to sense water level in tank.

**broken link removed**

eTape comes in 4 lengths. Max length is 32 inches. Buy eTape of different lengths to get desired measuring length and then connect them in series and use ADC to detect water level. The cost of the sensor is little high but will simplify the task.

 

[antus]

I made that wlc on a breadboard and it worked well but the problem is no dry run protection for the motor which is a must for water level controllers

 

[milan.rajik]

For dry run feature you should sense water level in Sump (tank from where you pump water). You can use magnetic float switches (horizontal mount or vertical mount). If water level in Sump is low then pump should be deactivated irrespective of over-head tank water level. If you can spend more then you can use flow sensor. Put electronic flow sensor between foot valve and pump. If there is no water then MCU will detect it from flow sensor and shut down pump.



https://www.ebay.com/bhp/water-flow-sensor

https://www.sensirion.com/en/products/liquid-flow-sensors/

https://www.futurlec.com/Flow_Sensor.shtml

 

[antus]

flow sensor is good but which controller circuit has the flow sensor option?

 

[milan.rajik]

Flow Sensor gives digital pulses proportional to speed of fluid flow. If no fluid is flowing you get no pulse. When MCU doesn't get pulse say for 100 ms then it means there is no fluid flowing. The rate of flow of water is fixed in your example and hence no. of pulses you get from flow sensor. lat's assume that flow sensor gives 50 pulses/sec for your system's rate of flow of water. So, you should get 5 pulses / 100 ms. If you don't get 5 pulses in 100 ms then disable the pump.