35 lines
1.7 KiB
Plaintext
35 lines
1.7 KiB
Plaintext
Name Shivam
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1. Question text:
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Design a system using a conductive water sensor (basically two metal probes that are very close together - when water is present between the probes it conducts) to detect when water level in a tank falls below 20% and when that happens, turn on a pump. The pump is a 3-phase 3-wire 1kW rated. This is for an industrial application where the water is being used for a chemical process. Design the system with some fail-safe such that the tank should never become empty.
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2. Design summary:
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Good approach. For reliability it is ok to say good quality components but beyond that how doyou ensure fail safe?
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e.g. one way is to have redundancy - multiple sensors; bakckup alerts, etc.
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for example, what if the relay fails? Or the motor is powered but the pump is blocked etc?
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You need to close the loop from the circuit instructing the motor to be on but pump not working somehow.
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What about over-rides? What if your box fails - is it possible to manually enable/disable the motor if needed?
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3. Block diagram
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your block diagram is a muddle of electrical, signal and mechanical items. Think a little about how to make a readable and clear diagram
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4. Power supply design
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Looks like your voltage level diagrams have some mistake. when tank is 100% full, all ABC lines should be ~12V.
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Why are you realising gates through transistors? Can't you just use 74LSxx series chips?
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5. Industrial Design:
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Could have been more detailed - with mechanical details, specific material etc.s
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6. KICAD Design
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Schematic:
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Looks good
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PCB:
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No PCB Found. I've deducted some points for that but other responses are all ok.
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7. Pricing / BOM / Assembly
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Why do you need 400V transistors?
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Where are remaining components in the BOM + pricing? Connectors, pcb, etc...?
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