<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
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    .badge-success { background: #dcfce7; color: #16a34a; }

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    canvas {
      width: 100%;
      height: 100%;
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    }

    /* Amplifier Math Block */
    .amp-stage {
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    }
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      color: #64748b;
      font-weight: bold;
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  </style>
</head>
<body>

  
  <div class="header">
    <div class="title-group">
      <span class="title">Single-Ended vs Differential Amplification</span>
    </div>
    <div class="ctrl-group">
      <div class="slider-container">
        <span>Noise:</span>
        <input type="range" id="noiseSlider" min="0" max="3" step="0.1" value="1.5">
        <span id="noiseVal" style="width:30px;font-family:monospace;">1.5V</span>
      </div>
      <button class="btn" id="playBtn">⏸ Pause</button>
    </div>
  </div>

  
  <div class="legend-bar">
    <div class="legend-item">
      <div class="swatch" style="background:#06b6d4;"></div>
      <span>Target Signal (10 mV)</span>
    </div>
    <div class="legend-item">
      <div class="swatch" style="background:#f59e0b;"></div>
      <span>Common-Mode Noise</span>
    </div>
    <div class="legend-item">
      <div class="swatch" style="background:#ef4444;"></div>
      <span>Clipped Output (±12V)</span>
    </div>
    <div class="legend-item">
      <div class="swatch" style="background:#10b981;"></div>
      <span>Pure Differential Output</span>
    </div>
  </div>

  
  <div class="comparison-grid">

    
    <div class="column-panel">
      <div class="panel-header">
        <span>Single-Ended (V<sub>in</sub> to GND)</span>
        <span class="badge badge-error" id="seBadge">Rail Saturated</span>
      </div>

      
      <div class="scope-box">
        <div class="scope-header">
          <span>Input: V<sub>sig</sub> + V<sub>noise</sub></span>
          <span class="scope-readout" id="seInReadout">V<sub>p-p</sub>: 3.02 V</span>
        </div>
        <div class="canvas-container">
          <canvas id="seInCanvas"></canvas>
        </div>
      </div>

      
      <div class="amp-stage">
        <span class="amp-tag">Gain ×100</span>
        <span>V<sub>out</sub> = 100 × V<sub>in</sub></span>
        <span class="arrow-down">↓</span>
      </div>

      
      <div class="scope-box">
        <div class="scope-header">
          <span style="color:#f87171;">Output: Severely Clipped</span>
          <span class="scope-readout" id="seOutReadout" style="color:#f87171;">±12.0 V Rails</span>
        </div>
        <div class="canvas-container">
          <canvas id="seOutCanvas"></canvas>
        </div>
      </div>
    </div>

    
    <div class="column-panel">
      <div class="panel-header">
        <span>Differential (V₁ &amp; V₂)</span>
        <span class="badge badge-success">Clean Signal Recovered</span>
      </div>

      
      <div class="scope-box">
        <div class="scope-header">
          <span>Inputs: Solid=V₁ (Sig+Noise), Dashed=V₂ (Noise)</span>
          <span class="scope-readout" id="diffInReadout">ΔV: 20 mV</span>
        </div>
        <div class="canvas-container">
          <canvas id="diffInCanvas"></canvas>
        </div>
      </div>

      
      <div class="amp-stage">
        <span class="amp-tag" style="background:#dcfce7;color:#166534;">CMRR Amp ×100</span>
        <span>V<sub>out</sub> = 100 × (V₁ − V₂)</span>
        <span class="arrow-down">↓</span>
      </div>

      
      <div class="scope-box">
        <div class="scope-header">
          <span style="color:#34d399;">Output: Pure Sine Wave</span>
          <span class="scope-readout" id="diffOutReadout" style="color:#34d399;">V<sub>p-p</sub>: 2.00 V</span>
        </div>
        <div class="canvas-container">
          <canvas id="diffOutCanvas"></canvas>
        </div>
      </div>
    </div>

  </div>

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    const noiseVal = document.getElementById('noiseVal');
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    const seOutReadout = document.getElementById('seOutReadout');

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    const seOutCanvas = document.getElementById('seOutCanvas');
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        canvas.height = rect.height * dpr;
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    window.addEventListener('resize', initCanvases);
    initCanvases();

    noiseSlider.addEventListener('input', (e) => {
      noiseAmp = parseFloat(e.target.value);
      noiseVal.textContent = noiseAmp.toFixed(1) + 'V';
      updateBadges();
    });

    playBtn.addEventListener('click', () => {
      isPlaying = !isPlaying;
      playBtn.textContent = isPlaying ? '⏸ Pause' : '▶ Play';
    });

    function updateBadges() {
      const vppIn = (noiseAmp * 2 + 0.02).toFixed(2);
      seInReadout.innerHTML = `V<sub>p-p</sub>: ${vppIn} V`;

      if (noiseAmp >= 0.12) {
        seBadge.className = 'badge badge-error';
        seBadge.textContent = 'Rail Saturated';
        seOutReadout.textContent = '±12.0 V Rails';
      } else if (noiseAmp > 0.02) {
        seBadge.className = 'badge badge-warn';
        seBadge.textContent = 'Noisy Output';
        seOutReadout.textContent = `Vp-p: ${(noiseAmp * 200).toFixed(1)} V`;
      } else {
        seBadge.className = 'badge badge-success';
        seBadge.textContent = 'Marginal Noise';
        seOutReadout.textContent = `Vp-p: 2.00 V`;
      }
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      ctx.stroke();

      // Center baseline
      ctx.strokeStyle = '#334155';
      ctx.beginPath();
      ctx.moveTo(0, h / 2);
      ctx.lineTo(w, h / 2);
      ctx.stroke();

      if (showRails) {
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        ctx.strokeStyle = '#ef4444';
        ctx.lineWidth = 1;
        
        ctx.beginPath();
        ctx.moveTo(0, h * 0.15);
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        ctx.moveTo(0, h * 0.85);
        ctx.lineTo(w, h * 0.85);
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        ctx.fillStyle = '#ef4444';
        ctx.font = `${Math.max(9, h * 0.12)}px monospace`;
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        const midY = h / 2;
        const pts = 120;

        if (c === seInCanvas) {
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          ctx.lineWidth = 2;
          ctx.beginPath();
          for (let i = 0; i <= pts; i++) {
            const x = (i / pts) * w;
            const t = time + (i / pts) * 3;
            const sig = 0.08 * Math.sin(t * 14); // scaled for visibility
            const noise = (noiseAmp / 3.0) * 0.35 * Math.sin(t * 2.5 + Math.sin(t * 5) * 0.3);
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          ctx.beginPath();
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          ctx.stroke();
          ctx.setLineDash([]);

          // V1 = Signal + Noise (cyan solid)
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          ctx.lineWidth = 2;
          ctx.beginPath();
          for (let i = 0; i <= pts; i++) {
            const x = (i / pts) * w;
            const t = time + (i / pts) * 3;
            const sig = 0.08 * Math.sin(t * 14);
            const noise = (noiseAmp / 3.0) * 0.35 * Math.sin(t * 2.5 + Math.sin(t * 5) * 0.3);
            const y = midY - (sig + noise) * h;
            if (i === 0) ctx.moveTo(x, y);
            else ctx.lineTo(x, y);
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          ctx.stroke();

        } else if (c === diffOutCanvas) {
          // Differential output: perfectly clean amplified signal
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          ctx.lineWidth = 2.5;
          ctx.beginPath();
          for (let i = 0; i <= pts; i++) {
            const x = (i / pts) * w;
            const t = time + (i / pts) * 3;
            const sig = 0.32 * Math.sin(t * 14);
            const y = midY - sig * h;
            if (i === 0) ctx.moveTo(x, y);
            else ctx.lineTo(x, y);
          }
          ctx.stroke();
        }
      });

      requestAnimationFrame(render);
    }

    updateBadges();
    requestAnimationFrame(render);
  </script>
</body>
</html>

Differential Voltage Amplification and Difference Amplifiers

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
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      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
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      color: #1e293b;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px;
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      width: 100%;
      max-width: 580px;
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      flex-direction: column;
      align-items: center;
      gap: 10px;
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      background: #ffffff;
      border-radius: 10px;
      border: 1px solid #e2e8f0;
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    svg {
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      height: auto;
      display: block;
      max-height: 290px;
    }

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    .junction { fill: #1e293b; }
    
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      gap: 8px;
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    .slider-row {
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      align-items: center;
      justify-content: space-between;
      gap: 12px;
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    .slider-label {
      font-size: 13px;
      font-weight: 700;
      color: #0284c7;
      white-space: nowrap;
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    input[type="range"] {
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      font-size: 11px;
      font-weight: 600;
      cursor: pointer;
    }

    .btn-step:hover {
      background: #e2e8f0;
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  </style>
</head>
<body>

  <div class="main-wrap">
    
    <div class="schematic-box">
      <svg viewBox="0 0 460 250">
        
        <defs>
          <filter id="glow" x="-20%" y="-20%" width="140%" height="140%">
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        <line x1="135" y1="135" x2="135" y2="125" class="wire"/>

        
        <circle cx="135" cy="125" r="4" fill="#7c3aed"/>
        <rect x="100" y="103" width="30" height="18" rx="4" fill="#ede9fe" stroke="#c4b5fd" stroke-width="1"/>
        <text x="115" y="116" class="node-pill" fill="#6d28d9">V₊</text>
      </svg>
    </div>

    
    <div class="controls-panel">
      <div class="slider-row">
        <span class="slider-label" id="vinDisplay">V_in = +0.0 V</span>
        <input type="range" id="vinSlider" min="-50" max="50" value="0" step="1">
        <div class="btn-group">
          <button class="btn-step" id="btnLow">−4V</button>
          <button class="btn-step" id="btnHigh">+4V</button>
        </div>
      </div>

      <div class="status-row">
        <span class="badge badge-node" id="vplusDisplay">V₊ = +2.5 V (Threshold)</span>
        <span class="badge badge-out-high" id="voutBadge">V_out = +V_sat (+5V)</span>
      </div>
    </div>
  </div>

  <script>
    // System Parameters
    const VSAT = 5.0;     // Saturation magnitude: +/- 5V
    const RATIO = 0.5;    // R1 / (R1 + R2) = 0.5  => V_th = +/- 2.5V
    let vOutState = VSAT; // Initial state: +V_sat

    const slider = document.getElementById('vinSlider');
    const vinDisplay = document.getElementById('vinDisplay');
    const vplusDisplay = document.getElementById('vplusDisplay');
    const voutBadge = document.getElementById('voutBadge');
    
    const wireVout = document.getElementById('wireVout');
    const dotVout = document.getElementById('dotVout');
    const lblVout = document.getElementById('lblVout');
    const wireVin = document.getElementById('wireVin');

    function updateCircuit() {
      const vin = parseFloat(slider.value) / 10;
      const vTh = vOutState * RATIO; // Switching threshold depends on CURRENT saturation output

      // Inverting Schmitt Trigger switching logic:
      // If V_out is +V_sat, it switches to -V_sat ONLY when V_in rises ABOVE +V_th
      // If V_out is -V_sat, it switches to +V_sat ONLY when V_in drops BELOW -V_th
      if (vOutState > 0 && vin > vTh) {
        vOutState = -VSAT;
      } else if (vOutState < 0 && vin < vTh) {
        vOutState = VSAT;
      }

      // Re-evaluate threshold after potential switch
      const currentThreshold = vOutState * RATIO;

      // Update Slider Label
      vinDisplay.textContent = `V_in = ${vin >= 0 ? '+' : ''}${vin.toFixed(1)} V`;

      // Update V+ Display
      vplusDisplay.textContent = `V₊ = ${currentThreshold >= 0 ? '+' : ''}${currentThreshold.toFixed(1)} V (${currentThreshold > 0 ? 'Upper' : 'Lower'} Threshold)`;

      // Update Output Display & Diagram Colors
      if (vOutState > 0) {
        voutBadge.className = "badge badge-out-high";
        voutBadge.textContent = `V_out = +V_sat (+${VSAT.toFixed(0)}V)`;
        wireVout.style.stroke = "#15803d";
        dotVout.setAttribute("fill", "#15803d");
        lblVout.setAttribute("fill", "#15803d");
      } else {
        voutBadge.className = "badge badge-out-low";
        voutBadge.textContent = `V_out = −V_sat (−${VSAT.toFixed(0)}V)`;
        wireVout.style.stroke = "#b91c1c";
        dotVout.setAttribute("fill", "#b91c1c");
        lblVout.setAttribute("fill", "#b91c1c");
      }

      // Vin wire color hint
      wireVin.style.stroke = vin > currentThreshold ? '#b91c1c' : '#0284c7';
    }

    slider.addEventListener('input', updateCircuit);

    document.getElementById('btnLow').addEventListener('click', () => {
      slider.value = -40;
      updateCircuit();
    });

    document.getElementById('btnHigh').addEventListener('click', () => {
      slider.value = 40;
      updateCircuit();
    });

    // Initialize state
    updateCircuit();
  </script>
</body>
</html>

Schmitt Trigger Circuits and Positive Feedback Hysteresis

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      user-select: none;
      -webkit-user-select: none;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      background: transparent;
      padding: 4px 6px;
      display: flex;
      flex-direction: column;
      gap: 6px;
      max-width: 680px;
      margin: 0 auto;
    }

    .controls {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 6px 10px;
      padding: 6px 8px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 6px;
    }

    .ctrl-group {
      display: flex;
      align-items: center;
      gap: 8px;
      flex: 1;
      min-width: 180px;
    }

    .btn {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 5px;
      padding: 4px 9px;
      font-size: 11.5px;
      font-weight: 600;
      color: #1e2945;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: background 0.15s ease, border-color 0.15s ease;
      white-space: nowrap;
    }

    .btn:active {
      background: #e2e8f0;
    }

    .slider-wrap {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 11px;
      font-weight: 600;
      color: #475569;
      flex: 1;
    }

    input[type="range"] {
      flex: 1;
      min-width: 60px;
      height: 5px;
      accent-color: #2563eb;
      cursor: pointer;
    }

    .panel {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 6px;
      padding: 5px 6px 4px 6px;
      display: flex;
      flex-direction: column;
      gap: 3px;
    }

    .header-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 4px;
      font-size: 11.5px;
      font-weight: 700;
      color: #1e2945;
    }

    .badge {
      font-size: 10px;
      font-weight: 600;
      padding: 1.5px 6px;
      border-radius: 8px;
      white-space: nowrap;
    }

    .badge-error {
      background: #fee2e2;
      color: #b91c1c;
      border: 1px solid #fca5a5;
    }

    .badge-success {
      background: #dcfce7;
      color: #15803d;
      border: 1px solid #86efac;
    }

    .canvas-container {
      position: relative;
      width: 100%;
      height: 152px;
      background: #fafbfc;
      border-radius: 4px;
      border: 1px solid #f1f5f9;
      overflow: hidden;
    }

    canvas {
      display: block;
      width: 100%;
      height: 100%;
    }

    .legend-bar {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      align-items: center;
      font-size: 10.5px;
      font-weight: 600;
      color: #64748b;
    }

    .legend-item {
      display: flex;
      align-items: center;
      gap: 4px;
      white-space: nowrap;
    }

    .line-dot {
      width: 10px;
      height: 2.5px;
      border-radius: 1px;
    }
  </style>
</head>
<body>

  
  <div class="controls">
    <div class="ctrl-group">
      <button class="btn" id="playBtn">⏸ Pause</button>
      <div class="slider-wrap">
        <span>Noise:</span>
        <input type="range" id="noiseSlider" min="0.04" max="0.28" step="0.01" value="0.14">
        <span id="noiseVal" style="min-width: 24px;">14%</span>
      </div>
    </div>
    <div class="legend-bar">
      <div class="legend-item"><span class="line-dot" style="background:#64748b;"></span> V<sub>in</sub></div>
      <div class="legend-item"><span class="line-dot" style="background:#ef4444; border-top: 1px dashed #ef4444;"></span> V<sub>ref</sub></div>
      <div class="legend-item"><span class="line-dot" style="background:#10b981; border-top: 1px dashed #10b981;"></span> V<sub>UT</sub></div>
      <div class="legend-item"><span class="line-dot" style="background:#3b82f6; border-top: 1px dashed #3b82f6;"></span> V<sub>LT</sub></div>
    </div>
  </div>

  
  <div class="panel">
    <div class="header-row">
      <span>1. Standard Comparator (Single Threshold)</span>
      <span class="badge badge-error">Rapid Output Chatter ✕</span>
    </div>
    <div class="canvas-container" id="cont1">
      <canvas id="compCanvas"></canvas>
    </div>
  </div>

  
  <div class="panel">
    <div class="header-row">
      <span>2. Schmitt Trigger (Hysteresis Band ΔV<sub>H</sub>)</span>
      <span class="badge badge-success">Clean Glitch-Free ✓</span>
    </div>
    <div class="canvas-container" id="cont2">
      <canvas id="schmittCanvas"></canvas>
    </div>
  </div>

  <script>
    const compCanvas = document.getElementById('compCanvas');
    const schmittCanvas = document.getElementById('schmittCanvas');
    const playBtn = document.getElementById('playBtn');
    const noiseSlider = document.getElementById('noiseSlider');
    const noiseVal = document.getElementById('noiseVal');

    const ctx1 = compCanvas.getContext('2d');
    const ctx2 = schmittCanvas.getContext('2d');

    let playing = true;
    let phase = 0;
    let noiseAmp = 0.14;

    const SAMPLES = 300;
    const V_UT = 0.38;
    const V_LT = -0.38;
    const V_REF = 0.0;

    noiseSlider.addEventListener('input', (e) => {
      noiseAmp = parseFloat(e.target.value);
      noiseVal.textContent = Math.round(noiseAmp * 100) + '%';
    });

    playBtn.addEventListener('click', () => {
      playing = !playing;
      playBtn.textContent = playing ? '⏸ Pause' : '▶ Play';
    });

    function getSignal(t, noise) {
      const pure = Math.sin(t);
      const highFreqNoise = 
        noise * Math.sin(t * 11.3 + 1.2) * 0.45 + 
        noise * Math.cos(t * 23.7 - 0.5) * 0.35 + 
        noise * Math.sin(t * 47.1 + 2.1) * 0.20;
      return pure + highFreqNoise;
    }

    function resizeCanvas(canvas) {
      const dpr = window.devicePixelRatio || 1;
      const rect = canvas.getBoundingClientRect();
      const w = Math.max(rect.width, 240);
      const h = Math.max(rect.height, 120);
      if (canvas.width !== Math.round(w * dpr) || canvas.height !== Math.round(h * dpr)) {
        canvas.width = Math.round(w * dpr);
        canvas.height = Math.round(h * dpr);
      }
      return { w, h, dpr };
    }

    function render() {
      const d1 = resizeCanvas(compCanvas);
      const d2 = resizeCanvas(schmittCanvas);

      if (playing) {
        phase += 0.025;
      }

      // Generate signal samples across screen
      const points = [];
      const compOut = [];
      const schmittOut = [];
      let lastSchmitt = -1;

      // Warm up Schmitt trigger state before t=0
      for (let i = -50; i <= SAMPLES; i++) {
        const t = phase + (i / SAMPLES) * Math.PI * 3.5;
        const val = getSignal(t, noiseAmp);
        if (val >= V_UT) lastSchmitt = 1;
        else if (val <= V_LT) lastSchmitt = -1;

        if (i >= 0) {
          points.push(val);
          compOut.push(val >= V_REF ? 1 : -1);
          schmittOut.push(lastSchmitt);
        }
      }

      // Draw Panel 1 (Comparator)
      drawPanel(ctx1, d1.w, d1.h, d1.dpr, {
        points,
        outData: compOut,
        isSchmitt: false,
        outColor: '#ef4444'
      });

      // Draw Panel 2 (Schmitt Trigger)
      drawPanel(ctx2, d2.w, d2.h, d2.dpr, {
        points,
        outData: schmittOut,
        isSchmitt: true,
        outColor: '#10b981'
      });

      requestAnimationFrame(render);
    }

    function drawPanel(ctx, w, h, dpr, cfg) {
      ctx.save();
      ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
      ctx.scale(dpr, dpr);

      const leftPad = 42;
      const rightPad = 10;
      const plotW = w - leftPad - rightPad;

      const inTop = 13;
      const inH = h * 0.45;
      const inMid = inTop + inH / 2;
      const inScale = inH * 0.42;

      const outTop = h * 0.63;
      const outH = h * 0.28;
      const outMid = outTop + outH / 2;
      const outScale = outH * 0.42;

      // Divider & Section labels
      ctx.fillStyle = '#94a3b8';
      ctx.font = '600 8.5px system-ui';
      ctx.textAlign = 'left';
      ctx.fillText('INPUT Vin(t)', leftPad, inTop - 2);
      ctx.fillText('OUTPUT Vout(t)', leftPad, outTop - 3);

      // Horizontal reference lines (zero levels)
      ctx.strokeStyle = '#e2e8f0';
      ctx.lineWidth = 1;
      ctx.setLineDash([]);
      ctx.beginPath();
      ctx.moveTo(leftPad, inMid);
      ctx.lineTo(w - rightPad, inMid);
      ctx.moveTo(leftPad, outMid);
      ctx.lineTo(w - rightPad, outMid);
      ctx.stroke();

      // Voltage labels on Y-axis
      ctx.font = 'bold 8px system-ui';
      ctx.textAlign = 'right';
      ctx.fillStyle = '#64748b';
      ctx.fillText('0V', leftPad - 4, inMid + 3);

      // Threshold lines
      if (!cfg.isSchmitt) {
        // Comparator reference line
        const yRef = inMid - V_REF * inScale;
        ctx.strokeStyle = '#ef4444';
        ctx.lineWidth = 1.2;
        ctx.setLineDash([4, 3]);
        ctx.beginPath();
        ctx.moveTo(leftPad, yRef);
        ctx.lineTo(w - rightPad, yRef);
        ctx.stroke();

        ctx.fillStyle = '#dc2626';
        ctx.fillText('Vref=0V', leftPad - 4, yRef + 3);
      } else {
        // Upper threshold
        const yUT = inMid - V_UT * inScale;
        ctx.strokeStyle = '#10b981';
        ctx.lineWidth = 1.2;
        ctx.setLineDash([4, 3]);
        ctx.beginPath();
        ctx.moveTo(leftPad, yUT);
        ctx.lineTo(w - rightPad, yUT);
        ctx.stroke();

        ctx.fillStyle = '#059669';
        ctx.fillText('V_UT', leftPad - 4, yUT + 3);

        // Lower threshold
        const yLT = inMid - V_LT * inScale;
        ctx.strokeStyle = '#3b82f6';
        ctx.lineWidth = 1.2;
        ctx.setLineDash([4, 3]);
        ctx.beginPath();
        ctx.moveTo(leftPad, yLT);
        ctx.lineTo(w - rightPad, yLT);
        ctx.stroke();

        ctx.fillStyle = '#2563eb';
        ctx.fillText('V_LT', leftPad - 4, yLT + 3);

        // Hysteresis band shading
        ctx.fillStyle = 'rgba(59, 130, 246, 0.05)';
        ctx.fillRect(leftPad, yUT, plotW, yLT - yUT);
      }

      // Draw Input Waveform
      ctx.setLineDash([]);
      ctx.strokeStyle = '#475569';
      ctx.lineWidth = 1.6;
      ctx.lineJoin = 'round';
      ctx.beginPath();
      for (let i = 0; i < cfg.points.length; i++) {
        const x = leftPad + (i / (cfg.points.length - 1)) * plotW;
        const y = inMid - cfg.points[i] * inScale;
        if (i === 0) ctx.moveTo(x, y);
        else ctx.lineTo(x, y);
      }
      ctx.stroke();

      // Output Saturation labels
      ctx.font = 'bold 8px system-ui';
      ctx.fillStyle = '#64748b';
      ctx.textAlign = 'right';
      ctx.fillText('+Vsat', leftPad - 4, outMid - outScale + 3);
      ctx.fillText('-Vsat', leftPad - 4, outMid + outScale + 3);

      // Draw Output Waveform
      ctx.strokeStyle = cfg.outColor;
      ctx.lineWidth = 1.8;
      ctx.beginPath();
      for (let i = 0; i < cfg.outData.length; i++) {
        const x = leftPad + (i / (cfg.outData.length - 1)) * plotW;
        const y = outMid - cfg.outData[i] * outScale;
        if (i === 0) {
          ctx.moveTo(x, y);
        } else {
          const prevY = outMid - cfg.outData[i - 1] * outScale;
          if (prevY !== y) {
            ctx.lineTo(x, prevY);
          }
          ctx.lineTo(x, y);
        }
      }
      ctx.stroke();

      ctx.restore();
    }

    window.addEventListener('resize', () => {
      resizeCanvas(compCanvas);
      resizeCanvas(schmittCanvas);
    });

    requestAnimationFrame(render);
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      width: 100%;
      font-family: system-ui, -apple-system, sans-serif;
      background: #f8fafc;
      color: #1e293b;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 6px 10px;
      user-select: none;
    }
    .graph-container {
      width: 100%;
      max-width: 480px;
      position: relative;
    }
    svg {
      width: 100%;
      height: auto;
      display: block;
    }
    .label-shield {
      paint-order: stroke fill;
      stroke: #f8fafc;
      stroke-width: 4.5px;
      stroke-linejoin: round;
    }
    .ctrl-panel {
      width: 100%;
      max-width: 460px;
      margin-top: 2px;
      display: flex;
      flex-direction: column;
      gap: 6px;
    }
    .slider-row {
      display: flex;
      align-items: center;
      gap: 10px;
      background: #ffffff;
      padding: 6px 12px;
      border-radius: 8px;
      border: 1px solid #e2e8f0;
    }
    .slider-label {
      font-size: 13px;
      font-weight: 700;
      color: #334155;
      min-width: 34px;
    }
    input[type="range"] {
      flex: 1;
      height: 6px;
      accent-color: #2563eb;
      cursor: pointer;
    }
    .status-badge {
      font-size: 11px;
      font-weight: 600;
      padding: 2px 8px;
      border-radius: 4px;
      background: #eff6ff;
      color: #1d4ed8;
      white-space: nowrap;
    }
    .btn-row {
      display: flex;
      justify-content: center;
      gap: 8px;
    }
    button {
      flex: 1;
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 6px;
      padding: 6px 12px;
      font-size: 12px;
      font-weight: 600;
      color: #334155;
      cursor: pointer;
      transition: background-color 0.15s ease, border-color 0.15s ease;
    }
    button:hover {
      background: #f1f5f9;
      border-color: #94a3b8;
    }
    button:active {
      background: #e2e8f0;
    }
  </style>
</head>
<body>
  <div class="graph-container">
    <svg viewBox="0 0 460 270">
      <defs>
        
        <marker id="arrow-axis" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1.5 L 8 5 L 0 8.5 z" fill="#64748b" />
        </marker>
        
        <marker id="loop-arrow" viewBox="0 0 10 10" refX="5" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 1 2 L 7 5 L 1 8 z" fill="#2563eb" />
        </marker>
        <marker id="hys-arrow" viewBox="0 0 10 10" refX="5" refY="5" markerWidth="5" markerHeight="5" orient="auto-start-reverse">
          <path d="M 1 2 L 7 5 L 1 8 z" fill="#059669" />
        </marker>
      </defs>

      
      <line x1="35" y1="145" x2="425" y2="145" stroke="#64748b" stroke-width="1.5" marker-end="url(#arrow-axis)" />
      <line x1="230" y1="260" x2="230" y2="18" stroke="#64748b" stroke-width="1.5" marker-end="url(#arrow-axis)" />

      
      <text x="430" y="149" font-size="13" font-weight="700" fill="#334155" class="label-shield">V<tspan font-size="10" dy="2">in</tspan></text>
      <text x="238" y="20" font-size="13" font-weight="700" fill="#334155" class="label-shield">V<tspan font-size="10" dy="2">out</tspan></text>

      
      <line x1="150" y1="75" x2="150" y2="215" stroke="#cbd5e1" stroke-width="1.5" stroke-dasharray="4 3" />
      <line x1="310" y1="75" x2="310" y2="215" stroke="#cbd5e1" stroke-width="1.5" stroke-dasharray="4 3" />
      <line x1="50" y1="75" x2="230" y2="75" stroke="#e2e8f0" stroke-width="1" stroke-dasharray="3 3" />
      <line x1="230" y1="215" x2="410" y2="215" stroke="#e2e8f0" stroke-width="1" stroke-dasharray="3 3" />

      
      <line x1="226" y1="75" x2="234" y2="75" stroke="#64748b" stroke-width="1.5" />
      <line x1="226" y1="215" x2="234" y2="215" stroke="#64748b" stroke-width="1.5" />
      <line x1="150" y1="141" x2="150" y2="149" stroke="#64748b" stroke-width="1.5" />
      <line x1="310" y1="141" x2="310" y2="149" stroke="#64748b" stroke-width="1.5" />

      
      <text x="222" y="70" font-size="12" font-weight="700" fill="#475569" text-anchor="end" class="label-shield">+V<tspan font-size="9" dy="2">sat</tspan></text>
      <text x="222" y="230" font-size="12" font-weight="700" fill="#475569" text-anchor="end" class="label-shield">-V<tspan font-size="9" dy="2">sat</tspan></text>
      <text x="150" y="165" font-size="12" font-weight="700" fill="#2563eb" text-anchor="middle" class="label-shield">V<tspan font-size="9" dy="2">LT</tspan></text>
      <text x="310" y="165" font-size="12" font-weight="700" fill="#2563eb" text-anchor="middle" class="label-shield">V<tspan font-size="9" dy="2">UT</tspan></text>

      
      <line x1="157" y1="38" x2="303" y2="38" stroke="#059669" stroke-width="1.5" marker-start="url(#hys-arrow)" marker-end="url(#hys-arrow)" />
      <line x1="150" y1="33" x2="150" y2="43" stroke="#059669" stroke-width="1.5" />
      <line x1="310" y1="33" x2="310" y2="43" stroke="#059669" stroke-width="1.5" />
      <text x="230" y="33" font-size="11.5" font-weight="700" fill="#059669" text-anchor="middle" class="label-shield">ΔV<tspan font-size="8.5" dy="2">H</tspan><tspan dy="-2"> = V</tspan><tspan font-size="8.5" dy="2">UT</tspan><tspan dy="-2"> − V</tspan><tspan font-size="8.5" dy="2">LT</tspan></text>

      
      
      <line x1="50" y1="75" x2="310" y2="75" stroke="#2563eb" stroke-width="2.75" stroke-linecap="round" />
      
      <line x1="310" y1="75" x2="310" y2="215" stroke="#2563eb" stroke-width="2.75" stroke-linecap="round" />
      
      <line x1="310" y1="215" x2="410" y2="215" stroke="#2563eb" stroke-width="2.75" stroke-linecap="round" />
      
      <line x1="410" y1="215" x2="150" y2="215" stroke="#2563eb" stroke-width="2.75" stroke-linecap="round" />
      
      <line x1="150" y1="215" x2="150" y2="75" stroke="#2563eb" stroke-width="2.75" stroke-linecap="round" />

      
      <line x1="205" y1="75" x2="225" y2="75" stroke="#2563eb" stroke-width="2.75" marker-end="url(#loop-arrow)" />
      <line x1="310" y1="135" x2="310" y2="155" stroke="#2563eb" stroke-width="2.75" marker-end="url(#loop-arrow)" />
      <line x1="255" y1="215" x2="235" y2="215" stroke="#2563eb" stroke-width="2.75" marker-end="url(#loop-arrow)" />
      <line x1="150" y1="155" x2="150" y2="135" stroke="#2563eb" stroke-width="2.75" marker-end="url(#loop-arrow)" />

      
      <g id="statePoint" transform="translate(50, 75)">
        <circle r="9" fill="#f59e0b" opacity="0.25" />
        <circle r="5" fill="#f59e0b" stroke="#ffffff" stroke-width="1.5" />
      </g>
    </svg>
  </div>

  <div class="ctrl-panel">
    <div class="slider-row">
      <span class="slider-label">V<sub style="font-size:10px;">in</sub></span>
      <input type="range" id="vinSlider" min="50" max="410" value="50" step="1" aria-label="Input Voltage">
      <span class="status-badge" id="statusBadge">Vout = +Vsat</span>
    </div>
    <div class="btn-row">
      <button id="btnSweepUp">Sweep Rising (→)</button>
      <button id="btnSweepDown">Sweep Falling (←)</button>
    </div>
  </div>

  <script>
    const slider = document.getElementById('vinSlider');
    const statePoint = document.getElementById('statePoint');
    const statusBadge = document.getElementById('statusBadge');
    const btnUp = document.getElementById('btnSweepUp');
    const btnDown = document.getElementById('btnSweepDown');

    const V_LT = 150;
    const V_UT = 310;
    const Y_HIGH = 75;
    const Y_LOW = 215;

    let currentState = 'HIGH';
    let animTimer = null;

    function updateState(xVal) {
      if (currentState === 'HIGH') {
        if (xVal >= V_UT) {
          currentState = 'LOW';
        }
      } else {
        if (xVal <= V_LT) {
          currentState = 'HIGH';
        }
      }

      const yVal = (currentState === 'HIGH') ? Y_HIGH : Y_LOW;
      statePoint.setAttribute('transform', `translate(${xVal}, ${yVal})`);

      if (currentState === 'HIGH') {
        statusBadge.textContent = 'Vout = +Vsat (HIGH)';
        statusBadge.style.background = '#eff6ff';
        statusBadge.style.color = '#1d4ed8';
      } else {
        statusBadge.textContent = 'Vout = -Vsat (LOW)';
        statusBadge.style.background = '#fef2f2';
        statusBadge.style.color = '#b91c1c';
      }
    }

    slider.addEventListener('input', (e) => {
      clearInterval(animTimer);
      updateState(parseFloat(e.target.value));
    });

    btnUp.addEventListener('click', () => {
      clearInterval(animTimer);
      slider.value = 50;
      currentState = 'HIGH';
      updateState(50);

      animTimer = setInterval(() => {
        let val = parseFloat(slider.value) + 3;
        if (val >= 410) {
          val = 410;
          slider.value = val;
          updateState(val);
          clearInterval(animTimer);
        } else {
          slider.value = val;
          updateState(val);
        }
      }, 16);
    });

    btnDown.addEventListener('click', () => {
      clearInterval(animTimer);
      slider.value = 410;
      currentState = 'LOW';
      updateState(410);

      animTimer = setInterval(() => {
        let val = parseFloat(slider.value) - 3;
        if (val <= 50) {
          val = 50;
          slider.value = val;
          updateState(val);
          clearInterval(animTimer);
        } else {
          slider.value = val;
          updateState(val);
        }
      }, 16);
    });

    updateState(50);
  </script>
</body>
</html>

ELEC-8.3

Aligned learning resources

Related diagrams