.. title: ボルト・ワット・アンペア変換
.. スラグ: ボルトワットアンペアコンバータ
.. 日付: 2025-12-26 15:00:00 UTC
.. タグ: ネットワーキング、電卓、ツール
.. カテゴリ: 電卓
..リンク:
.. 説明: ボルト ワット アンペア変換 - オンライン計算ツール
.. タイプ: テキスト
<style>
    .calc-container {
        max-width: 900px;
        margin: 20px auto;
        padding: 20px;
    }

    .calc-header {
        margin-bottom: 30px;
        padding: 25px;
        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        border-radius: 12px;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        color: white;
    }

    .calc-header h2 {
        margin-top: 0;
        color: white;
        font-size: 28px;
        margin-bottom: 10px;
    }

    .calc-header p {
        margin: 10px 0;
        opacity: 0.95;
        font-size: 15px;
    }

    .input-grid {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 15px;
        margin-top: 20px;
    }

    .input-group {
        display: flex;
        flex-direction: column;
    }

    .input-group label {
        margin-bottom: 8px;
        font-weight: 600;
        color: rgba(255,255,255,0.95);
        font-size: 14px;
    }

    .input-group input {
        padding: 14px;
        font-size: 16px;
        border: 2px solid rgba(255,255,255,0.3);
        border-radius: 6px;
        font-family: 'Courier New', monospace;
        background: rgba(255,255,255,0.95);
        transition: all 0.3s ease;
    }

    .input-group input:focus {
        outline: none;
        border-color: #4CAF50;
        background: white;
        box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.1);
    }

    .button-container {
        margin-top: 20px;
        display: flex;
        justify-content: center;
    }

    .calc-button {
        padding: 14px 35px;
        font-size: 16px;
        background: #4CAF50;
        color: white;
        border: none;
        border-radius: 6px;
        cursor: pointer;
        font-weight: bold;
        transition: all 0.3s ease;
        box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    }

    .calc-button:hover {
        background: #45a049;
        transform: translateY(-1px);
        box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    }

    .calc-button:active {
        background: #3d8b40;
        transform: translateY(0);
    }

    .result-section {
        background: white;
        border: 1px solid #e0e0e0;
        border-radius: 8px;
        margin-top: 30px;
        overflow: hidden;
        box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        transition: all 0.3s ease;
    }

    .result-section:hover {
        box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    }

    .section-header {
        background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
        color: white;
        padding: 15px 20px;
        font-size: 18px;
        font-weight: bold;
    }

    .section-content {
        padding: 20px;
        background: #fafafa;
    }

    .result-grid {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 15px;
    }

    .data-row {
        display: flex;
        flex-direction: column;
        padding: 15px;
        background: white;
        border-radius: 6px;
        border-left: 4px solid #4CAF50;
        box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    }

    .data-label {
        font-weight: bold;
        color: #555;
        font-size: 14px;
        margin-bottom: 8px;
        text-transform: uppercase;
        letter-spacing: 0.5px;
    }

    .data-value {
        color: #333;
        font-family: 'Courier New', monospace;
        font-size: 24px;
        font-weight: bold;
        color: #4CAF50;
    }

    .help-text {
        margin-top: 15px;
        font-size: 14px;
        color: rgba(255,255,255,0.9);
        background: rgba(0,0,0,0.1);
        padding: 10px 15px;
        border-radius: 4px;
    }

    .help-text strong {
        color: white;
    }

    .formula-info {
        margin-top: 20px;
        padding: 15px;
        background: #e3f2fd;
        color: #1565c0;
        border-radius: 8px;
        border-left: 4px solid #2196F3;
        font-size: 14px;
        line-height: 1.6;
    }

    .formula-info strong {
        color: #0d47a1;
    }

    .checkbox-group {
        margin-top: 15px;
        display: flex;
        align-items: center;
        gap: 10px;
        background: rgba(0,0,0,0.1);
        padding: 12px 15px;
        border-radius: 6px;
    }

    .checkbox-group input[type="checkbox"] {
        width: 20px;
        height: 20px;
        cursor: pointer;
        accent-color: #4CAF50;
    }

    .checkbox-group label {
        margin-bottom: 0;
        cursor: pointer;
        font-size: 15px;
        user-select: none;
    }

    .phase-indicator {
        display: inline-block;
        padding: 4px 12px;
        background: #4CAF50;
        color: white;
        border-radius: 4px;
        font-size: 13px;
        font-weight: bold;
        margin-left: 10px;
    }

    /* Responsive design */
    @media (max-width: 768px) {
        .input-grid,
        .result-grid {
            grid-template-columns: 1fr;
        }

        .calc-header h2 {
            font-size: 24px;
        }

        .data-value {
            font-size: 20px;
        }
    }
</style>
<div class="calc-container">
<div class="calc-header">
<h2>ボルト・ワット・アンペア変換計算機</h2>
<p>電圧、ワット数、アンペア数の間の電力の関係を計算します。任意の 2 つの値を入力して、3 番目の値を計算します。</p>
<div class="input-grid">
<div class="input-group">
<label for="voltage">電圧 (V):</label>
<input autocomplete="off" id="voltage" type="text" value="0"/>
</div>
<div class="input-group">
<label for="wattage">ワット数(W):</label>
<input autocomplete="off" id="wattage" type="text" value="0"/>
</div>
<div class="input-group">
<label for="amperage">アンペア数 (A):</label>
<input autocomplete="off" id="amperage" type="text" value="0"/>
</div>
</div>
<div class="checkbox-group">
<input id="threePhase" onchange="voltwattamp()" type="checkbox"/>
<label for="threePhase">3 相電源 (線間電圧に √3 乗算器を使用)</label>
</div>
<div class="button-container">
<button class="calc-button" onclick="voltwattamp()" type="button">計算する</button>
</div>
<div class="help-text">
<strong>使用方法:</strong>任意の 2 つの値 (電圧、ワット数、またはアンペア数) を入力し、「計算」をクリックして 3 番目の値を見つけます。三相電力を計算するには、[3 相] ボックスをオンにします。</div>
</div>
<div class="result-section">
<div class="section-header">計算結果<span class="phase-indicator" id="phaseIndicator">単相</span>
</div>
<div class="section-content">
<div class="result-grid">
<div class="data-row">
<div class="data-label">計算された電圧:</div>
<div class="data-value" id="voltResult">-</div>
</div>
<div class="data-row">
<div class="data-label">計算されたワット数:</div>
<div class="data-value" id="wattResult">-</div>
</div>
<div class="data-row">
<div class="data-label">計算されたアンペア数:</div>
<div class="data-value" id="ampResult">-</div>
</div>
</div>
<div class="formula-info" id="formulaInfo">
<strong>使用される公式 (単相):</strong><br/>電圧 (V) = ワット数 (W) / アンペア数 (A)<br/>ワット数 (W) = 電圧 (V) × アンペア数 (A)<br/>アンペア数 (A) = ワット数 (W) / 電圧 (V)</div>
</div>
</div>
</div>
<script>
function voltwattamp() {
    // Set variables from input
    var volt = Number(document.getElementById("voltage").value);
    var watt = Number(document.getElementById("wattage").value);
    var amp = Number(document.getElementById("amperage").value);

    // Check if 3-phase is enabled
    var isThreePhase = document.getElementById("threePhase").checked;
    var multiplier = isThreePhase ? Math.sqrt(3) : 1; // √3 ≈ 1.732

    // Calculate results based on phase type
    var voltres, wattres, ampres;

    if (isThreePhase) {
        /*
        3-Phase formulas (assuming unity power factor and line-to-line voltage):
        P = √3 × V × I
        V = P / (√3 × I)
        I = P / (√3 × V)
        */
        voltres = watt / (multiplier * amp);
        wattres = multiplier * volt * amp;
        ampres = watt / (multiplier * volt);
    } else {
        /*
        Single-phase formulas:
        V = P / I
        P = V × I
        I = P / V
        */
        voltres = watt / amp;
        wattres = volt * amp;
        ampres = watt / volt;
    }

    // Format results with units
    document.getElementById("voltResult").innerHTML = isFinite(voltres) ? voltres.toFixed(2) + ' V' : '-';
    document.getElementById("wattResult").innerHTML = isFinite(wattres) ? wattres.toFixed(2) + ' W' : '-';
    document.getElementById("ampResult").innerHTML = isFinite(ampres) ? ampres.toFixed(2) + ' A' : '-';

    // Update phase indicator
    document.getElementById("phaseIndicator").textContent = isThreePhase ? '3-Phase' : 'Single-Phase';

    // Update formula display
    var formulaInfo = document.getElementById("formulaInfo");
    if (isThreePhase) {
        formulaInfo.innerHTML = `
            <strong>Formulas used (3-Phase):</strong><br>
            Voltage (V) = Wattage (W) / (√3 × Amperage (A))<br>
            Wattage (W) = √3 × Voltage (V) × Amperage (A)<br>
            Amperage (A) = Wattage (W) / (√3 × Voltage (V))<br>
            <em>Note: √3 ≈ 1.732 (assumes unity power factor and line-to-line voltage)</em>
        `;
    } else {
        formulaInfo.innerHTML = `
            <strong>Formulas used (Single-Phase):</strong><br>
            Voltage (V) = Wattage (W) / Amperage (A)<br>
            Wattage (W) = Voltage (V) × Amperage (A)<br>
            Amperage (A) = Wattage (W) / Voltage (V)
        `;
    }
}

// Add enter key support for inputs
document.addEventListener('DOMContentLoaded', function() {
    const inputs = document.querySelectorAll('#voltage, #wattage, #amperage');
    inputs.forEach(input => {
        input.addEventListener('keypress', function(e) {
            if (e.key === 'Enter') {
                voltwattamp();
            }
        });
    });
});
</script>