Transformers and Power Supplies
Converter Duty Cycle Calculator
Converter Duty Cycle helps you find ideal duty cycle from output voltage and input voltage. The page keeps the arithmetic visible so you can check the result against the original measurements.
Set up the Converter Duty Cycle case
Enter ratings or measurements that describe one scenario.
Understanding the equation
This page evaluates D = Vout ÷ Vin × 100. The participating entries are Output voltage and Input voltage.
For the example shown, ideal duty cycle equals 41.67%. Treat that value as a demonstration, not a recommendation.
Calculate ideal duty cycle from output voltage and input voltage. If you also need ideal boost output, continue with Boost Converter Calculator.
Values this page needs
Record waveform, frequency, load level, and winding or device temperature. A source note beside each entry makes the result reproducible.
A denominator entry cannot be zero. Convert units once, retain the original reading, and verify the converted magnitude.
- Output voltage
- Default example: 5 V. Enter output voltage in V.
- Input voltage
- Default example: 12 V. Enter input voltage in V.
Applying the result
The primary answer, Ideal duty cycle, describes only the entered scenario. Compare it with a no-load, nominal-load, and limiting-load case.
Label alternate cases rather than overwriting the baseline.
Practical limits
Topology and loss alter practical duty cycle.
The equation does not include leakage inductance, parasitic capacitance, saturation, switching transients, and cooling. Use measurements, manufacturer data, or another calculation for effects that can change the decision.
Use voltage and current values from the same side of the transformer or converter.
Sensitivity check
Change Output voltage from 5 V to 6 V with every other entry unchanged. The result changes from 41.67% to 50.00%.
The comparison demonstrates sensitivity, not a guaranteed field response.
Keep a reproducible record
Save output voltage and input voltage with ideal duty cycle. Add the date and any unit conversion.
Carry ideal duty cycle unchanged when passing it to the next worksheet. Do not round between dependent calculations.
Questions about inputs and assumptions
Can I select equipment from this number alone?
Use the number as one check, then review a no-load, nominal-load, and limiting-load case.
How much precision should I keep?
Keep full precision while transferring ideal duty cycle; round only at the final reporting or selection step.
What happens when a denominator is zero?
Input voltage is used in a denominator and must be greater than zero.
Should I use measured or nameplate values?
Measured and rated values can represent different states. Identify RMS, average, peak, and rectified quantities explicitly.
What assumptions affect Ideal duty cycle?
The result follows the displayed variables. Check leakage inductance, parasitic capacitance, saturation, switching transients, and cooling separately.
What explains a gap between calculated and observed ideal duty cycle?
First confirm that the measurements match the equation. Then review leakage inductance, parasitic capacitance, saturation, switching transients, and cooling.