دائرة تنبيه عند طفحان الخزانات Overflow Indicator Circuit
Overflow Indicator Circuit
The unit can be placed in the room for easy monitoring. Fix the sensor close to the lid of the overhead tank. Connect the sensor with the points A and B using long plastic wire. Since the copper tracts in the sensor may corrode due to weathering, periodic cleaning or replacement is necessary. To avoid this two brass pins or screws can be used. But these should be arranged closely with minimum spacing of 2mm between them. Then only current passes through water and the brass pins.
Power supply can be 9 volt battery or a 9 volt 500 mA DC adapter. Use a small 2 inch 4 ohms speaker. To get loud voice, use AC 187 or an NPN Darlington transistor in the place of T3 (BC547).
دائرة تنبيه عند طفحان الخزانات Overflow Indicator Circuit
