Dc Rate Calculator

by
Duty Cycle (DC) Rate Calculator for PWM :root { –primary-color: #2563eb; –secondary-color: #1e40af; –bg-color: #f3f4f6; –card-bg: #ffffff; –text-color: #1f2937; –border-color: #e5e7eb; } body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; line-height: 1.6; color: var(–text-color); background-color: var(–bg-color); margin: 0; padding: 20px; } .container { max-width: 800px; margin: 0 auto; } .calculator-card { background: var(–card-bg); border-radius: 12px; box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06); padding: 30px; margin-bottom: 40px; } .calculator-header { text-align: center; margin-bottom: 25px; } .calculator-title { font-size: 1.8rem; color: var(–primary-color); margin: 0; font-weight: 700; } .input-group { margin-bottom: 20px; } .input-group label { display: block; margin-bottom: 8px; font-weight: 600; font-size: 0.95rem; } .input-wrapper { position: relative; display: flex; align-items: center; } .input-field { width: 100%; padding: 12px 15px; border: 1px solid var(–border-color); border-radius: 6px; font-size: 1rem; transition: border-color 0.2s; } .input-field:focus { outline: none; border-color: var(–primary-color); box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1); } .unit-label { position: absolute; right: 15px; color: #6b7280; font-size: 0.9rem; pointer-events: none; } .calc-btn { width: 100%; background-color: var(–primary-color); color: white; border: none; padding: 14px; font-size: 1.1rem; font-weight: 600; border-radius: 6px; cursor: pointer; transition: background-color 0.2s; margin-top: 10px; } .calc-btn:hover { background-color: var(–secondary-color); } .results-section { margin-top: 30px; padding: 20px; background-color: #f8fafc; border-radius: 8px; border: 1px solid var(–border-color); display: none; } .result-row { display: flex; justify-content: space-between; align-items: center; padding: 10px 0; border-bottom: 1px solid #e2e8f0; } .result-row:last-child { border-bottom: none; } .result-label { font-weight: 600; color: #4b5563; } .result-value { font-weight: 700; font-size: 1.25rem; color: var(–primary-color); } .error-msg { color: #dc2626; background-color: #fef2f2; padding: 10px; border-radius: 6px; margin-top: 15px; display: none; text-align: center; font-weight: 500; } .content-section { background: var(–card-bg); padding: 30px; border-radius: 12px; box-shadow: 0 2px 4px rgba(0,0,0,0.05); } h2 { color: var(–text-color); border-bottom: 2px solid var(–bg-color); padding-bottom: 10px; margin-top: 30px; } h3 { color: #4b5563; margin-top: 25px; } p, li { color: #4b5563; } .formula-box { background: #eef2ff; padding: 15px; border-left: 4px solid var(–primary-color); font-family: monospace; margin: 20px 0; overflow-x: auto; } @media (max-width: 600px) { .calculator-card, .content-section { padding: 20px; } }

Duty Cycle (DC) Rate Calculator

Calculate PWM Duty Cycle, Frequency, and Output Voltage

ms
The duration the signal is active (HIGH).
ms
The total time for one complete cycle ($t_{on} + t_{off}$).
Volts
Maximum voltage amplitude of the signal.
Duty Cycle Rate (DC): 0%
Signal Frequency: 0 Hz
Average Output Voltage: 0 V

Understanding Duty Cycle (DC) Rate

In electronics and signal processing, the Duty Cycle (DC) represents the fraction of one period in which a signal or system is active. It is widely used in Pulse Width Modulation (PWM) to control power delivery to devices such as motors, LEDs, and heating elements.

A "DC Rate" of 50% implies that the signal is HIGH for exactly half of the time and LOW for the other half, resulting in an average voltage exactly half of the input source.

The Duty Cycle Formula

The standard formula to calculate the duty cycle percentage is:

Duty Cycle (%) = (Pulse Width / Total Period) × 100

Where:

  • Pulse Width ($t_{on}$): The time duration the signal is in the active or high state.
  • Total Period ($T$): The time it takes for the signal to complete one full ON/OFF cycle.

Calculating Average Voltage

One of the primary uses of calculating the DC rate is to determine the average output voltage ($V_{avg}$) seen by the load. This effectively converts a digital signal into an analog voltage level.

$V_{avg}$ = $V_{in}$ × (Duty Cycle / 100)

For example, if you have a 12V source and apply a 25% duty cycle, the effective voltage powering your device will be 3V.

Frequency vs. Period

The period is inversely proportional to the frequency. If you know the frequency of your PWM controller (e.g., an Arduino running at 490 Hz), you can calculate the period using:

Period ($T$) = 1 / Frequency ($f$)

Using our calculator above, entering the pulse width and period allows you to verify if your signal timing meets the requirements for your specific electronic application.

function calculateDCRate() { // Clear previous errors var errorDiv = document.getElementById('error-message'); var resultsDiv = document.getElementById('results'); errorDiv.style.display = 'none'; resultsDiv.style.display = 'none'; // Get inputs var pwInput = document.getElementById('pulseWidth').value; var periodInput = document.getElementById('period').value; var voltInput = document.getElementById('peakVoltage').value; // Parse inputs var pw = parseFloat(pwInput); var period = parseFloat(periodInput); var volts = parseFloat(voltInput); // Validation Logic if (isNaN(pw) || isNaN(period)) { errorDiv.innerHTML = "Please enter valid numbers for Pulse Width and Period."; errorDiv.style.display = 'block'; return; } if (period <= 0) { errorDiv.innerHTML = "Signal Period must be greater than 0."; errorDiv.style.display = 'block'; return; } if (pw period) { errorDiv.innerHTML = "Pulse Width cannot be greater than the Total Period."; errorDiv.style.display = 'block'; return; } // Calculations var dutyCycle = (pw / period) * 100; // Frequency Calculation (Since inputs are in ms, Frequency = 1000 / T) var frequency = 1000 / period; // Average Voltage Calculation (if voltage provided) var avgVoltage = 0; var showVoltage = false; if (!isNaN(volts) && voltInput.trim() !== "") { avgVoltage = volts * (dutyCycle / 100); showVoltage = true; } // Display Results document.getElementById('result-dc').innerHTML = dutyCycle.toFixed(2) + '%'; // Format frequency nicely (e.g., use kHz if > 1000) if (frequency >= 1000) { document.getElementById('result-freq').innerHTML = (frequency / 1000).toFixed(2) + ' kHz'; } else { document.getElementById('result-freq').innerHTML = frequency.toFixed(2) + ' Hz'; } // Show/Hide Voltage Row var avgVoltRow = document.getElementById('avg-volt-row'); if (showVoltage) { document.getElementById('result-avg-volt').innerHTML = avgVoltage.toFixed(2) + ' V'; avgVoltRow.style.display = 'flex'; } else { avgVoltRow.style.display = 'none'; } resultsDiv.style.display = 'block'; }

Leave a Comment