1. What is ESR of Capacitor?

Equivalent Series Resistance (ESR) represents the total resistive losses in a capacitor. It includes the resistance of the dielectric, electrodes, leads, and connections. Lower ESR values indicate better capacitor performance and efficiency.

2. How Does the Calculator Work?

The calculator uses the ESR equation:

Where:

• \( ESR \) — Equivalent Series Resistance (ohms)
• \( DF \) — Dissipation Factor (unitless)
• \( f \) — Frequency (Hz)
• \( C \) — Capacitance (farads)

Explanation: The equation calculates the effective resistance in series with an ideal capacitor that would account for the same energy losses as the actual capacitor.

3. Importance of ESR Calculation

Details: ESR is critical for power supply filtering, high-frequency applications, and determining capacitor heating and efficiency. High ESR can lead to poor performance and reduced capacitor lifespan.

4. Using the Calculator

Tips: Enter dissipation factor (DF), frequency in Hz, and capacitance in farads. All values must be positive numbers. For microfarads, divide by 1,000,000 (e.g., 10μF = 0.00001F).

5. Frequently Asked Questions (FAQ)

Q1: What is a typical ESR value for capacitors?
A: ESR varies by capacitor type. Electrolytics: 0.01-1Ω, Ceramics: 0.001-0.1Ω, Tantalums: 0.01-0.5Ω. Lower is generally better.

Q2: How does frequency affect ESR?
A: ESR typically decreases with increasing frequency up to a point, then may increase due to parasitic effects and dielectric losses.

Q3: Why is ESR important in power supplies?
A: High ESR causes increased ripple voltage, reduced filtering effectiveness, and can lead to capacitor overheating and failure.

Q4: How to measure ESR directly?
A: Using an ESR meter or impedance analyzer that applies a small AC signal and measures the resistive component at the test frequency.

Q5: Does temperature affect ESR?
A: Yes, ESR generally decreases with increasing temperature, though the relationship varies by capacitor type and materials.