Dear Mr.Bill3857,Mr.KMoffett, Mr.Blueroomelectronics,Mr. LED3,Mr..Ramesh,
Please allow me to thank you for your comments.May I reply to each comment one by one.
Mr.Bill3857- No sir, I am aware that wheel, or for that any invention, is invented only once. What follows later by mere mortals like me, is trying to understand it. I am trying to understand electronics by working with hands.
Mr.KMoffett, yes partially true for the reason that unless you work with your own hands learning is not complete, particularly in experimental sciences.
Mr.Blueroomelectronics- the answer lies in the desire to learn by working out real life problem. I would guess your observation would be true.
Mr.LDC3- May I go over how standard level controller works.There are two probes, three or more as required by condition, one of them being main and others input probes. An input probe receives voltage/current when it is in water and otherwise this input is zero.This is used to operate transistor switch.There are two transistor switches in the negative path of relay coil going to the ground in my circuit. It is either closed or open depending upon the inputs from both probes. These inputs are managed in such a way that both gates are closed when the necessary conditions are satisfied.Three transistors in the circuit that I am using does that precisely-that is my expectation.
The answer to the second question is contained in the necessary condition for pumping to start, that is-and I reproduce -"IF (i) water level at the top should be below specified level in the upper tank AND (ii) water level in the lower tank should be above a specified level".
Mr.Ramesh: Your obervation-
"From you explanation, I gather:
1) Water pump must start when
the top tank has water Below a Set level
AND
the water in the lower tank is Above a Set level
2) The pump must stop when the upper tank fills up Above a Set Level
OR
the water in the lower tank is Below a Set Level (this condition is mine, given the above requirement; not yet included in the schematic)
the water in the lower tank is Below a Set Level (this condition is mine, given the above requirement; not yet included in the schematic)"
I should have added that as added condition that pumping should stop if water level goes below a set level ( which I think I had mentioned in the earlier write up);however by putting two switches in series, one dependent on U-probe and second on L-probe input, this condition gets satisfied since earthing is complete ONLY IF both gates are ON.
I appreciate your help and spending time in designing a circuit base on floating switches. I would imagine, not verified, it would be equivalent to circuit based on transistor switches up to the part of switching on/off of the main circuit.
I have verified that my circuit works on breadboard and only problem that I am facing is the original question of semi automatic switch for activating/deactivating main circuit.I am toying with idea of possibility of using Ridge(?) switch. I am 'unearthing' relevant material.
Since mine is an activity to appreciate electronics, my further reading has opened a new possibility, except the original question. It is using IC4093. Plan of action is -Use one NAND gate for activating two main probes with ac,convert ac received by receiving probes to dc, feed these two to NAND Gates which forms an AND gate and use remaining NAND gate NOT gate for the signal from L-tank probe before it is fed to AND gate. It is using logic of my circuit but IC 4093. The idea of using ac for probes is for avoiding electrolysis of probes,..
Let me see how it works.
Thanks again to all above kind people for their comments.
sureshparanjape
