Water Level Indicator

Water LeveL index WIth aLarm VIJay D. SaThE H ere is a simple, varied circuit which indicates the direct of piddle in a tank. This circuit produces warning device system when urine take aim is below the lowest direct L1 and also when water system just touches the highest level L12. The circuit is designed to display 12 different levels. However, these display levels can be increased or decreased depending upon the level resolution required. This can be do by increasing or fall the number of level sensor surface strips (L1 through L12) and their associated components. In the circuit, semiconductor diodes D1, D2 and D13 form half-wave rectifiers.The rectify output is filtered using capacitors C1 through C3 respectively. Initially, when water level is below strip L1, the mains preparation frequency oscillations are non transferred to diode D1. Thus its output is low and LED1 does not glow. Also, since base potency of transister T1 is low, it is in cut-off put up and it s collector voltage is high, which enables melody generating IC1 (UM66) and alarm is sounded. When water just touches level demodulator strip L1, the supply frequency oscillations are transferred to diode D1. It rectifies the supply voltage and a positive DC voltage develops across capacitor C1, which lights up LED1.At the identical time base voltage for transistor T1 becomes high, which makes it forward biased and its collector voltage falls to near-ground potential. This disables IC1 (UM66) and alarm is inhibited. Depending upon quantity of water present in the tank, corresponding level indicating LEDs glow. It thus displays intermediate water levels in the tank in bar-graph style. When water in the tank just touches the highest level detector strip L12, the DC voltage is create across capacitor C2. This enables melody generating IC1 (UM66) and alarm is again sounded. ELECTRONICS PROJECTS Vol. 20