{
  "node": {
    "id": "term:mosfet",
    "type": "Term",
    "label": "MOSFET",
    "properties": {
      "id": "mosfet",
      "name": "MOSFET",
      "aka": [
        "metal–oxide–semiconductor field-effect transistor",
        "power MOSFET"
      ],
      "section": "topic-data",
      "definition": "A transistor switched by the voltage on its gate, with an on-resistance of milliohms or less in power parts. Low-voltage packs use back-to-back pairs as charge and discharge switches, since each conducts backwards through its body diode; BMS chips use small ones for balancing, and silicon-carbide MOSFETs switch 800 V inverters.",
      "related": [
        "protection-circuit",
        "pulse-width-modulation",
        "cell-balancing",
        "inverter",
        "buck-boost-converter"
      ],
      "url": "https://lemonergy.com/learn/glossary/mosfet/",
      "mentions": [
        "bms"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:5232",
      "source": "term:mosfet",
      "target": "topic:topic-data",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5233",
      "source": "term:mosfet",
      "target": "term:protection-circuit",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5234",
      "source": "term:mosfet",
      "target": "term:pulse-width-modulation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5235",
      "source": "term:mosfet",
      "target": "term:cell-balancing",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5236",
      "source": "term:mosfet",
      "target": "term:inverter",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5237",
      "source": "term:mosfet",
      "target": "term:buck-boost-converter",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/mosfet/bms",
      "source": "term:mosfet",
      "target": "term:bms",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-data",
      "type": "Topic",
      "label": "Data, communication and electronics",
      "properties": {
        "id": "topic-data",
        "name": "Data, communication and electronics",
        "lede": "The control units, chips, protocols and file formats through which a battery is measured, controlled and logged.",
        "context": "Separate quantities from encoding and transport.",
        "example": "2500 in a log might mean 25.00 °C, 2.5 V or raw counts. Units and scale must accompany the value.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-basics/",
        "lesson_label": "Open battery basics"
      }
    },
    {
      "id": "term:protection-circuit",
      "type": "Term",
      "label": "Protection circuit module",
      "properties": {
        "id": "protection-circuit",
        "name": "Protection circuit module",
        "abbr": "PCM",
        "aka": [
          "protection board",
          "PCB"
        ],
        "section": "topic-pack",
        "definition": "The small circuit on a consumer cell or pack that disconnects it on overvoltage, undervoltage, overcurrent or overtemperature, using MOSFETs as switches. It is the minimum BMS; it protects but does not estimate state or balance.",
        "related": [
          "bms",
          "overcharge",
          "over-discharge",
          "fuel-gauge"
        ],
        "url": "https://lemonergy.com/learn/glossary/protection-circuit/",
        "mentions": []
      }
    },
    {
      "id": "term:pulse-width-modulation",
      "type": "Term",
      "label": "Pulse-width modulation",
      "properties": {
        "id": "pulse-width-modulation",
        "name": "Pulse-width modulation",
        "abbr": "PWM",
        "section": "topic-data",
        "definition": "Controlling average power by switching fully on and off at a fixed frequency and varying the fraction of each period spent on, the duty ratio. It drives fans, pumps and contactor coils, sets the output of DC/DC converters and inverters, and signals available current on the 1 kHz control pilot of an AC charger.",
        "formula": "V_avg = D·V_supply",
        "related": [
          "mosfet",
          "buck-boost-converter",
          "control-pilot",
          "coil-economiser",
          "inverter"
        ],
        "example": {
          "title": "Convert duty cycle to an ideal average",
          "text": "An ideal switch applying 12 V for 25% of each period produces a 3 V time average at the switching node. The instantaneous signal remains a 0/12 V waveform; a real converter also depends on topology and filtering."
        },
        "url": "https://lemonergy.com/learn/glossary/pulse-width-modulation/",
        "mentions": [
          "charger",
          "contactor"
        ]
      }
    },
    {
      "id": "term:cell-balancing",
      "type": "Term",
      "label": "Cell balancing",
      "properties": {
        "id": "cell-balancing",
        "name": "Cell balancing",
        "section": "topic-state",
        "definition": "Equalising the state of charge of cells in series, since the pack is limited by its emptiest cell on discharge and its fullest on charge. Passive balancing bleeds charge from high cells through resistors; active balancing moves it between cells.",
        "related": [
          "bms",
          "series-parallel",
          "state-of-charge",
          "cell-to-cell-variation"
        ],
        "example": {
          "title": "Pack average versus cell limits",
          "text": "Average pack SOC can look acceptable while one series cell reaches its voltage limit. One aggregate SOC state does not demonstrate cell balancing."
        },
        "url": "https://lemonergy.com/learn/glossary/cell-balancing/",
        "mentions": [
          "active-balancing"
        ]
      }
    },
    {
      "id": "term:inverter",
      "type": "Term",
      "label": "Inverter",
      "properties": {
        "id": "inverter",
        "name": "Inverter",
        "aka": [
          "power conversion system",
          "PCS"
        ],
        "section": "topic-pack",
        "definition": "The power electronics that turn the battery’s DC into AC for a motor or the grid, and back again for charging. In stationary storage it is called the power conversion system and its rating in kW or MW sets the system’s power independently of the battery’s energy.",
        "related": [
          "pre-charge",
          "dc-dc-converter",
          "stationary-storage",
          "energy-management-system",
          "direct-current",
          "iec-62477-1"
        ],
        "url": "https://lemonergy.com/learn/glossary/inverter/",
        "mentions": []
      }
    },
    {
      "id": "term:buck-boost-converter",
      "type": "Term",
      "label": "Buck and boost converters",
      "properties": {
        "id": "buck-boost-converter",
        "name": "Buck and boost converters",
        "aka": [
          "buck converter",
          "boost converter",
          "step-down converter",
          "step-up converter",
          "bidirectional DC/DC converter"
        ],
        "section": "topic-data",
        "definition": "Switch-mode circuits that step a DC voltage down (buck) or up (boost) using a fast switch, an inductor and a capacitor, often above 95% efficient. With transistors in place of diodes the same circuit runs both ways, charging a battery from a bus or discharging into it, as in stationary storage and on-board boosters that let 800 V cars use 400 V chargers.",
        "related": [
          "dc-dc-converter",
          "pulse-width-modulation",
          "mosfet",
          "active-balancing",
          "split-pack"
        ],
        "url": "https://lemonergy.com/learn/glossary/buck-boost-converter/",
        "mentions": [
          "stationary-storage",
          "capacitor"
        ]
      }
    },
    {
      "id": "term:bms",
      "type": "Term",
      "label": "Battery management system",
      "properties": {
        "id": "bms",
        "name": "Battery management system",
        "abbr": "BMS",
        "section": "topic-pack",
        "definition": "The electronics and software that keep a battery inside its safe window: measuring every cell voltage and many temperatures, estimating SOC and SOH, balancing cells, computing current limits, controlling the contactors and reporting over the vehicle network.",
        "related": [
          "state-of-charge",
          "cell-balancing",
          "state-of-power",
          "cell-supervision-circuit",
          "contactor",
          "can-bus"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "url": "https://lemonergy.com/learn/glossary/bms/",
        "mentions": [
          "state-of-health",
          "cell-voltage"
        ]
      }
    }
  ]
}