27 lines
1.7 KiB
Plaintext
27 lines
1.7 KiB
Plaintext
Balu Mahesh
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1. 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 is ok but could have been a little more detailed. Where is the fail-safe to prevent the tank from being completely empty?
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How do you prevent overflow? How do you prevent the motor from running when input supply is not present? What about when the pump fails?
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Basically there is no mention of the failsafe requirement.
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What are the tadeoffs? How are you balancing cost, efficiency, and reliability?
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What is the meaning of "Zero PCB or card board"?
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3. Block diagram: what is roof of the tank? The top of the tank? Or is the tank on the roof of a building?
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The block diagram is confusing: what is the meaning of "exception?" Which of thse lines are signal and which are power??
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4. Power supply design is totally absent.
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5. Industrial Design:
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Your text is directly lifted from https://sg.rs-online.com/web/c/enclosures-server-racks/enclosures/pcb-mounting-enclosures/
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6. KICAD Design
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Schematic:
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Did you use this circuit? even the values are identical: https://easyelectronicsproject.com/wp-content/uploads/2020/10/Water-Pump-Auto-Switch-Pic-12.jpg?x56667
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PCB:
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Layout seems ok
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DRC is not passing because there is no outline.
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7. Pricing / Assembly: Items costs are ok although grossly underestimated. No mention of materials for the actual probes, wiring, etc ???
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