Water LeveL IndIcator WIth aLarm VIJay D. SaThE H ere is a elementary, changeable circumference which indicates the plane of steep in a tank. This circumference produces terrify when steep plane is beneath the lowest plane L1 and besides when steep honorable touches the chief plane L12. The circumference is calculated to evince 12 divergent planes. However, these evince planes can be increased or decreased depending upon the plane disintegration required. This can be done by increasing or decreasing the enumerate of plane guide metal robs (L1 through L12) and their associated components. In the circumference, diodes D1, D2 and D13 construct half-wave rectifiers.
The rectified output is filtered using capacitors C1 through C3 respectively. Initially, when steep plane is beneath rob L1, the mains provide abundance oscillations are not epidemic to diode D1. Thus its output is low and LED1 does not interpretation. Also, since disingenuous voltage of transister T1 is low, it is in skin declare and its collector voltage is lofty, which enables music generating IC1 (UM66) and terrify is sounded. When steep honorable touches plane guide rob L1, the provide abundance oscillations are epidemic to diode D1. It rectifies the provide voltage and a enacted DC voltage develops athwart capacitor C1, which lights up LED1.
At the identical span disingenuous voltage for transistor T1 becomes lofty, which makes it bold inequitable and its collector voltage falls to near-ground implicit. This disables IC1 (UM66) and terrify is inhibited. Depending upon bulk of steep confer-upon in the tank, identical plane indicating LEDs interpretation. It thus evinces interjacent steep planes in the tank in bar-graph phraseology. When steep in the tank honorable touches the chief plane guide rob L12, the DC voltage is plain athwart capacitor C2. This enables music generating IC1 (UM66) and terrify is frequently sounded. ELECTRONICS PROJECTS Vol. 20