ESeries.js

/* E-Series Standard Component Value Finder — IEC 60063
 *
 *   Preferred values: Rₙ = 10^(n/N) · 10^decade,  n = 0..N−1
 *   E6→N=6, E12→N=12, E24→N=24, E48→N=48, E96→N=96, E192→N=192
 *   Nearest value found by minimum absolute error across ±1 decade.
 */

var E_SERIES = {
  E6:  [1.0, 1.5, 2.2, 3.3, 4.7, 6.8],
  E12: [1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2],
  E24: [1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0,
        3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1],
  E48: [1.00,1.05,1.10,1.15,1.21,1.27,1.33,1.40,1.47,1.54,1.62,1.69,
        1.78,1.87,1.96,2.05,2.15,2.26,2.37,2.49,2.61,2.74,2.87,3.01,
        3.16,3.32,3.48,3.65,3.83,4.02,4.22,4.42,4.64,4.87,5.11,5.36,
        5.62,5.90,6.19,6.49,6.81,7.15,7.50,7.87,8.25,8.66,9.09,9.53],
  E96: [1.00,1.02,1.05,1.07,1.10,1.13,1.15,1.18,1.21,1.24,1.27,1.30,
        1.33,1.37,1.40,1.43,1.47,1.50,1.54,1.58,1.62,1.65,1.69,1.74,
        1.78,1.82,1.87,1.91,1.96,2.00,2.05,2.10,2.15,2.21,2.26,2.32,
        2.37,2.43,2.49,2.55,2.61,2.67,2.74,2.80,2.87,2.94,3.01,3.09,
        3.16,3.24,3.32,3.40,3.48,3.57,3.65,3.74,3.83,3.92,4.02,4.12,
        4.22,4.32,4.42,4.53,4.64,4.75,4.87,4.99,5.11,5.23,5.36,5.49,
        5.62,5.76,5.90,6.04,6.19,6.34,6.49,6.65,6.81,6.98,7.15,7.32,
        7.50,7.68,7.87,8.06,8.25,8.45,8.66,8.87,9.09,9.31,9.53,9.76],
  E192:[1.00,1.01,1.02,1.04,1.05,1.06,1.07,1.09,1.10,1.11,1.13,1.14,
        1.15,1.17,1.18,1.20,1.21,1.23,1.24,1.26,1.27,1.29,1.30,1.32,
        1.33,1.35,1.37,1.38,1.40,1.42,1.43,1.45,1.47,1.49,1.50,1.52,
        1.54,1.56,1.58,1.60,1.62,1.64,1.65,1.67,1.69,1.72,1.74,1.76,
        1.78,1.80,1.82,1.84,1.87,1.89,1.91,1.93,1.96,1.98,2.00,2.03,
        2.05,2.08,2.10,2.13,2.15,2.18,2.21,2.23,2.26,2.29,2.32,2.34,
        2.37,2.40,2.43,2.46,2.49,2.52,2.55,2.58,2.61,2.64,2.67,2.71,
        2.74,2.77,2.80,2.84,2.87,2.91,2.94,2.98,3.01,3.05,3.09,3.12,
        3.16,3.20,3.24,3.28,3.32,3.36,3.40,3.44,3.48,3.52,3.57,3.61,
        3.65,3.70,3.74,3.79,3.83,3.88,3.92,3.97,4.02,4.07,4.12,4.17,
        4.22,4.27,4.32,4.37,4.42,4.48,4.53,4.59,4.64,4.70,4.75,4.81,
        4.87,4.93,4.99,5.05,5.11,5.17,5.23,5.30,5.36,5.42,5.49,5.56,
        5.62,5.69,5.76,5.83,5.90,5.97,6.04,6.12,6.19,6.26,6.34,6.42,
        6.49,6.57,6.65,6.73,6.81,6.90,6.98,7.06,7.15,7.23,7.32,7.41,
        7.50,7.59,7.68,7.77,7.87,7.96,8.06,8.16,8.25,8.35,8.45,8.56,
        8.66,8.76,8.87,8.98,9.09,9.20,9.31,9.42,9.53,9.65,9.76,9.88]
};

var UNIT_INFO = {
  'ohm':  { mul: 1,     base: 'Ω' },
  'kohm': { mul: 1e3,   base: 'Ω' },
  'Mohm': { mul: 1e6,   base: 'Ω' },
  'pF':   { mul: 1e-12, base: 'F' },
  'nF':   { mul: 1e-9,  base: 'F' },
  'uF':   { mul: 1e-6,  base: 'F' },
  'nH':   { mul: 1e-9,  base: 'H' },
  'uH':   { mul: 1e-6,  base: 'H' }
};

document.getElementById('es-btn').addEventListener('click', es_calc);

function es_calc() {
  clearError();
  var raw    = parseFloat(document.getElementById('es-val').value.trim());
  var unitKey = document.getElementById('es-unit').value;
  var series  = document.getElementById('es-series').value;

  if (!(raw > 0) || !isFinite(raw)) { showError('Enter a valid positive value.'); return; }

  var info   = UNIT_INFO[unitKey];
  var target = raw * info.mul;   // in base units (Ω / F / H)

  var nearest = findNearest(target, series);
  showResults(nearest, target, series, info.base);
}

function findNearest(target, series) {
  var table = E_SERIES[series];
  var log10 = Math.log(target) / Math.LN10;
  var decade = Math.floor(log10);
  var candidates = [];

  for (var d = decade - 1; d <= decade + 1; d++) {
    var mul = Math.pow(10, d);
    table.forEach(function(v) { candidates.push(v * mul); });
  }

  candidates.sort(function(a, b) {
    return Math.abs(a - target) - Math.abs(b - target);
  });

  var seen = {}, out = [];
  candidates.forEach(function(v) {
    var key = v.toPrecision(4);
    if (!seen[key] && out.length < 5) { seen[key] = true; out.push(v); }
  });
  return out;
}

function showResults(vals, target, series, baseUnit) {
  var container = document.getElementById('es-results');
  container.innerHTML = '';
  container.style.display = 'grid';

  var card = document.createElement('div');
  card.className = 'res-card';
  card.innerHTML = '<h4>' + series + ' — Nearest 5 Values</h4>' +
    '<div class="res-row" style="font-size:11px;color:#888;margin-bottom:4px;">' +
    '<span class="res-lbl">Standard value</span>' +
    '<span class="res-val">Error from target</span></div>';

  vals.forEach(function(v, i) {
    var err = (v - target) / target * 100;
    var errStr = (err >= 0 ? '+' : '') + err.toFixed(2) + '%';
    var label = engFmt(v, baseUnit);
    var hi = (i === 0) ? ' style="font-weight:700;color:#AA77FF;"' : '';
    card.innerHTML +=
      '<div class="res-row">' +
      '<span class="res-lbl"' + hi + '>' + label + '</span>' +
      '<span class="res-val"' + hi + '>' + errStr + '</span></div>';
  });

  container.appendChild(card);
  if (window.drawDiagram) window.drawDiagram(series, vals.length);
}

function showError(msg) {
  var el = document.getElementById('es-error');
  if (el) el.textContent = msg;
}
function clearError() {
  var el = document.getElementById('es-error');
  if (el) el.textContent = '';
}