{
  "backend": "ltspice",
  "checks_skipped": [],
  "circuit": {
    "components": [
      {
        "ref": "V1",
        "type": "voltage",
        "value": "SINE(0 16.9706 50)"
      },
      {
        "part": "1N4007",
        "ref": "D1",
        "type": "diode"
      },
      {
        "part": "1N4007",
        "ref": "D2",
        "type": "diode"
      },
      {
        "part": "1N4007",
        "ref": "D3",
        "type": "diode"
      },
      {
        "part": "1N4007",
        "ref": "D4",
        "type": "diode"
      },
      {
        "ref": "C1",
        "type": "cap",
        "value": "470u"
      },
      {
        "ref": "L1",
        "type": "ind",
        "value": "1m"
      },
      {
        "ref": "C2",
        "type": "cap",
        "value": "470u"
      },
      {
        "ref": "RS",
        "type": "res",
        "value": "220"
      },
      {
        "part": "DZ6V2",
        "ref": "DZ",
        "type": "zener"
      },
      {
        "ref": "RL",
        "type": "res",
        "value": "1k"
      }
    ],
    "directives": [
      ".model DZ6V2 D(BV=6.2 IBV=5m)"
    ],
    "nets": {
      "0": [
        "D3.anode",
        "D4.anode",
        "C1.b",
        "C2.b",
        "DZ.anode",
        "RL.b"
      ],
      "ac1": [
        "V1.+",
        "D1.anode",
        "D3.cathode"
      ],
      "ac2": [
        "V1.-",
        "D2.anode",
        "D4.cathode"
      ],
      "vfilt": [
        "L1.b",
        "C2.a",
        "RS.a"
      ],
      "vout": [
        "RS.b",
        "DZ.cathode",
        "RL.a"
      ],
      "vrect": [
        "D1.cathode",
        "D2.cathode",
        "C1.a",
        "L1.a"
      ]
    }
  },
  "deliverables": [
    {
      "kind": "ltspice-schematic",
      "path": "exp03-regulated-supply.asc",
      "sha256": "ffb91c6b0b6afa93467a95827153f53734379ae9ca1f6e2bfd0f52757734c10b",
      "unverified_reason": null,
      "verified": true,
      "verified_by": "emitted from the same circuit description that was simulated, and round-trips through the geometric parser. The exact bytes were not the ones handed to LTspice: the deliverable carries every run, with one active and the rest commented"
    },
    {
      "kind": "ltspice-plot",
      "path": "exp03-regulated-supply.plt",
      "sha256": "678d4e19bc5d789ecb5e1634bdfe71f066c187887f57e84f4aa92c282554f8b2",
      "unverified_reason": "batch mode does not read .plt, so no machine check exists for plot files; transcribed from LTspice's own examples, pending one visual confirmation in the GUI",
      "verified": false,
      "verified_by": null
    }
  ],
  "design_notes": [
    {
      "choice": "full bridge + C-L-C pi filter + shunt zener with series resistor",
      "item": "topology",
      "rationale": "the standard topology for this spec; the question names the blocks but not their interconnection or the zener's series resistor",
      "rationale_origin": "generated"
    }
  ],
  "designed_values": [
    {
      "origin": "designed",
      "rationale": "drops ~9 V from the ~15.2 V filter output, setting roughly 40 mA total: ~6 mA into the 1k load leaves the zener biased well above its 5 mA knee across the ripple swing",
      "rationale_origin": "generated",
      "ref": "RS",
      "value": "220"
    }
  ],
  "devices": {
    "D1": {
      "directive": null,
      "part": "1N4007",
      "policy": "nearest",
      "report": "question names no diode; using 1N4007 (general-purpose rectifier default)"
    },
    "D2": {
      "directive": null,
      "part": "1N4007",
      "policy": "nearest",
      "report": "question names no diode; using 1N4007 (general-purpose rectifier default)"
    },
    "D3": {
      "directive": null,
      "part": "1N4007",
      "policy": "nearest",
      "report": "question names no diode; using 1N4007 (general-purpose rectifier default)"
    },
    "D4": {
      "directive": null,
      "part": "1N4007",
      "policy": "nearest",
      "report": "question names no diode; using 1N4007 (general-purpose rectifier default)"
    },
    "DZ": {
      "directive": ".model DZ6V2 D(BV=6.2 IBV=5m)",
      "part": "DZ6V2",
      "policy": "synthesized",
      "report": "using a synthesised model: Vz=6.2 V anchored at a 5m test current, because the question specifies exactly 6.2 V and a nearby real part would answer a slightly different question"
    }
  },
  "generated": "2026-08-25",
  "manifest_version": 1,
  "plan": {
    "measurements": [
      {
        "expr": "V(ac1)-V(ac2)",
        "kind": "waveform_stats",
        "name": "v_in_wave",
        "run": "waveforms"
      },
      {
        "expr": "V(vrect)",
        "kind": "waveform_stats",
        "name": "v_rect_wave",
        "run": "waveforms"
      },
      {
        "expr": "V(vfilt)",
        "kind": "waveform_stats",
        "name": "v_filt_wave",
        "run": "waveforms"
      },
      {
        "expr": "V(vout)",
        "kind": "waveform_stats",
        "name": "v_out_wave",
        "run": "waveforms"
      },
      {
        "expr": "I(RL)",
        "kind": "waveform_stats",
        "name": "i_load_wave",
        "run": "waveforms"
      },
      {
        "assert": "zener_in_breakdown",
        "device": "DZ",
        "kind": "regime",
        "run": "waveforms",
        "vz": 6.2
      }
    ],
    "runs": [
      {
        "id": "waveforms",
        "label": "steady-state waveforms",
        "max_step": "100u",
        "settle": "100m",
        "stop": "200m",
        "type": "tran"
      }
    ]
  },
  "prose": [],
  "question": {
    "asks": [
      {
        "answered_by": "v_in_wave",
        "text": "input AC waveform"
      },
      {
        "answered_by": "v_rect_wave",
        "text": "bridge rectifier output waveform"
      },
      {
        "answered_by": "v_filt_wave",
        "text": "C-L-C filter output waveform"
      },
      {
        "answered_by": "v_out_wave",
        "text": "regulated DC output waveform"
      },
      {
        "answered_by": "i_load_wave",
        "text": "load current waveform"
      }
    ],
    "source": {
      "extractor": "human transcription from screenshot",
      "file": "lab manual, Experiment 3 open ended question (screenshot)"
    },
    "text": "Design and simulate a regulated 6.2 V DC power supply using LTspice. The circuit should consist of a bridge rectifier, a C-L-C smoothing filter with C = 470 \u00b5F and L = 1 mH, followed by a Zener-diode voltage regulator. The bridge rectifier is driven by a 12 V RMS, 50 Hz AC supply, and a 1 k\u03a9 resistive load is connected at the regulated output. Obtain and observe the input AC waveform, bridge rectifier output waveform, C-L-C filter output waveform, regulated DC output waveform, and load current waveform using LTspice."
  },
  "question_id": "exp03-regulated-supply",
  "regime_checks": [
    {
      "assertion": "zener_in_breakdown",
      "device": "DZ",
      "examined": "I(DZ) against a 0.0001 A minimum reverse current, and its terminal voltage against Vz=6.2 V, at 1115 sweep points of run 'waveforms'",
      "held": true,
      "reasons": [],
      "run": "waveforms"
    }
  ],
  "results": [
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      "backend": "ltspice",
      "name": "v_in_wave",
      "reliable": true,
      "run": "waveforms",
      "source": "simulation",
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        "mean": 8.139164439895255e-06,
        "min": -16.970591485500336,
        "ripple_pp": 33.941072046756744,
        "rms": 12.00014114961263
      },
      "value": 8.139164439895255e-06,
      "verification": "external",
      "warnings": []
    },
    {
      "backend": "ltspice",
      "name": "v_rect_wave",
      "reliable": true,
      "run": "waveforms",
      "source": "simulation",
      "stats": {
        "max": 15.732717514038086,
        "mean": 15.228354975039663,
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        "ripple_pp": 1.0394563674926758,
        "rms": 15.229587921210383
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      "verification": "external",
      "warnings": []
    },
    {
      "backend": "ltspice",
      "name": "v_filt_wave",
      "reliable": true,
      "run": "waveforms",
      "source": "simulation",
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        "max": 15.802033424377441,
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    },
    {
      "backend": "ltspice",
      "name": "v_out_wave",
      "reliable": true,
      "run": "waveforms",
      "source": "simulation",
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      "verification": "external",
      "warnings": []
    },
    {
      "backend": "ltspice",
      "name": "i_load_wave",
      "reliable": true,
      "run": "waveforms",
      "source": "simulation",
      "stats": {
        "max": 0.006251878570765257,
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  "warnings": []
}