1. What is ESR of a Capacitor?

Definition: Equivalent Series Resistance (ESR) represents the total losses in a capacitor, combining all resistive components into a single series resistance value.

Purpose: ESR is crucial for evaluating capacitor performance in circuits, especially in power supplies and high-frequency applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( ESR \) — Equivalent Series Resistance (ohms)
• \( \tan(\delta) \) — Loss tangent (dissipation factor)
• \( f \) — Frequency (Hz)
• \( C \) — Capacitance (farads)

Explanation: The loss tangent represents the dielectric losses, which when divided by the capacitive reactance gives the equivalent series resistance.

3. Importance of ESR Calculation

Details: Low ESR is critical for capacitors used in power filtering applications as it affects ripple voltage, efficiency, and heat generation.

4. Using the Calculator

Tips: Enter the loss tangent (typically found in capacitor datasheets), operating frequency, and capacitance value. All values must be > 0 except loss tangent which can be 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical loss tangent value?
A: It varies by capacitor type: 0.0001-0.001 for film caps, 0.01-0.1 for electrolytics, and 0.00001-0.0001 for ceramic caps.

Q2: Why does frequency affect ESR?
A: ESR typically decreases with frequency until the capacitor's self-resonant frequency, after which it increases.

Q3: How does ESR impact circuit performance?
A: High ESR causes more power loss, heat generation, and reduced filtering effectiveness in power supplies.

Q4: Can ESR be measured directly?
A: Yes, with an ESR meter or impedance analyzer, especially at the operating frequency.

Q5: What's the relationship between ESR and capacitor lifetime?
A: ESR typically increases as capacitors age, especially electrolytics, making it a useful failure indicator.