1. What is a Capacitor ESR Calculator?

Definition: This calculator estimates the Equivalent Series Resistance (ESR) of a capacitor based on its loss tangent, operating frequency, and capacitance.

Purpose: It helps electronics engineers and hobbyists determine the effective resistance in series with an ideal capacitor.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( ESR \) — Equivalent Series Resistance (ohms)
• \( \tan(\delta) \) — Loss tangent (dimensionless)
• \( f \) — Frequency (Hz)
• \( C \) — Capacitance (Farads)

Explanation: The loss tangent represents the dielectric loss, divided by the capacitive reactance to give the equivalent series resistance.

3. Importance of ESR Calculation

Details: ESR affects capacitor performance in circuits, influencing power loss, heat generation, and filtering effectiveness. Lower ESR is generally better for most applications.

4. Using the Calculator

Tips: Enter the loss tangent (from capacitor datasheet), operating frequency in Hz, and capacitance in Farads. 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 for high-quality film caps, 0.01-0.1 for electrolytics, and 0.001-0.01 for ceramic caps.

Q2: Why does frequency affect ESR?
A: ESR typically decreases with frequency due to changing dielectric behavior, though very high frequencies may increase it again.

Q3: How does ESR impact circuit design?
A: High ESR causes power loss, heating, and reduced filtering effectiveness, especially in power supply circuits.

Q4: Can ESR be measured directly?
A: Yes, with specialized LCR meters or by analyzing the capacitor's impedance phase angle.

Q5: Does temperature affect ESR?
A: Yes, particularly in electrolytic capacitors where ESR decreases as temperature increases.