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RCD Snubber Voltage Clamp Resistor & Power Loss Calculator

When the main MOSFET turns off, energy trapped in the transformer leakage inductance cannot transfer to the secondary.

Measured primary uncoupled leakage inductance

Peak drain current at MOSFET turn-off

Allowable overshoot voltage above reflected voltage

n * (Vout + Vd) reflected back to primary

Operating switching frequency

Calculated Result
3014 Ω

Clamp Resistor

Snubber Power Loss

8.49 W

Calculation Breakdown

  1. RCD Energy DissipationP_rcd = 8.49 W => R = 3014 Ω

Snubber Power vs Leakage Inductance

Interactive visualization based on your current inputs

Prcd
0.02.14.36.48.5Llk = 3 µHLlk = 6.5 µHLlk = 10 µHLeakage InductancePower (W)

What Is the RCD Snubber Voltage Clamp Resistor & Power Loss Calculator?

When the main MOSFET turns off, energy trapped in the transformer leakage inductance cannot transfer to the secondary.

An RCD clamp absorbs this inductive energy, protecting the MOSFET from avalanche breakdown.

How Does the RCD Snubber Voltage Clamp Resistor & Power Loss Calculator Work?

The calculation evaluates user-provided measurements using recognized domain equations, converts between measurement units, and adjusts for real-world efficiency factors.

RCD Snubber Voltage Clamp Resistor & Power Loss Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

P_{rcd} = \frac{1}{2} L_{lk} I_{pk}^2 f_{sw} \frac{V_{clamp}}{V_{clamp} - V_{or}}, \quad R = \frac{V_{clamp}^2}{P_{rcd}}

RCD clamp power dissipation and resistance sizing.

How to Use the RCD Snubber Voltage Clamp Resistor & Power Loss Calculator

  1. Enter your primary measurements in the input fields above.
  2. Select your preferred units (e.g. metric or imperial) if applicable.
  3. Review or adjust operational assumptions such as field efficiency.
  4. Click Calculate to instantly generate the full results breakdown and visual chart.
  5. Use the Reset button at any time to clear the form and test a new scenario.

Step-by-Step Example Calculation

Universal Input Flyback Clamp

Input Values:

leakageInductanceUh:8.0
peakPrimaryCurrentA:4.0
clampVoltageV:180
reflectedVoltageVorV:90
switchingFreqKhz:90

Understanding Your Result

Your calculated result represents the realistic operational capacity or baseline output under the specified conditions. Comparing theoretical and effective outputs reveals the direct impact of turns, overlap, and practical downtime.

Factors That Affect the Result

Field terrain, operator experience, equipment maintenance, overlap margin, and weather conditions can significantly influence real-world output.

When Should You Use This Calculator?

Use this calculator whenever you need quick, verified estimates for job planning, budgeting, equipment sizing, or project timelines.

Assumptions & Limitations

  • Vclamp must be kept strictly above Vor to allow the leakage energy to discharge during OFF time.

Frequently Asked Questions

Calculation Accuracy & Reference Note

This calculator implements verified, deterministic mathematical equations based on published standards. Results should be treated as professional engineering estimates; always verify critical operations with local equipment manuals and site inspections.

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