In most houses, water is first stored in an underground tank (UGT) and from there it is pumped up to the overhead tank (OHT) located on the roof. People generally switch on the pump when their taps go dry and switch off the pump when the overhead tank starts overflowing. This results in the unnecessary wastage and sometimes non-availability of water in the case of emergency. The simple circuit presented here makes this system automatic, i.e. it switches on the pump when the water level in the overhead tank goes low and ...
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In most houses, water is first stored in an underground tank (UGT) and from there it is pumped up to the overhead tank (OHT) located on the roof. People generally switch on the pump when their taps go dry and switch off the pump when the overhead tank starts overflowing. This results in the unnecessary wastage and sometimes non-availability of water in the case of emergency. The simple circuit presented here makes this system automatic, i.e. it switches on the pump when the water level in the overhead tank goes low and switches it off as soon as the water level reaches a pre-determined level. It also prevents 'dry run' of the pump in case the level in the underground tank goes below the suction level. In the figure, the common probes connecting the underground tank and the overhead tank to +9V supply are marked 'C'. The other probe in underground tank, which is slightly above the 'dry run' level, is marked 'S'. The low-level and high-level probes in the overhead tank are marked 'L' and 'H', respectively. When there is enough water in the underground tank, probes C and S are connected through waterAs a result, transistor T1 gets forward biased and starts conducting. This, in turn, switches transistor T2 on. Initially, when the overhead tank is empty, transistors T3and T5 are in cut-off state and hence pnp transistors T4 and T6 get forward biased via resistors R5 and R6, respectively. As all series-connected transistorsT2, T4, and T6 are forward biased, they conduct to energise relay RL1 (which is also connected in series with transistorsT2, T4, and T6). Thus the supply to the pump motor gets completed via the lowerset of relay contacts (assuming that switchS2 is on) and the pump starts filling the overhead tank. Once the relay has energised, transistor T6 is bypassed via the upper set of contacts of the relay. As soon as the water level touches probe L in the overhead tank, transistor T5 gets forwardbiased and starts conducting. This, in turn, reverse biases transistor T6, which then cuts off. But since transistor T6is bypassed throught he relay contacts, the pump continues to run. The level of water continues to rise.
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Add this copy of Water Level Controller to cart. $20.87, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2019 by Independently published.
