1. What is a Single Layer Coil Inductance Calculator?

Definition: This calculator estimates the inductance of a single-layer air-core coil using Wheeler's formula.

Purpose: It helps electronics engineers, hobbyists, and students design and analyze single-layer coils for various applications.

2. How Does the Calculator Work?

The calculator uses Wheeler's formula:

Where:

• \( L \) — Inductance (μH)
• \( r \) — Radius of the coil (inches)
• \( N \) — Number of turns
• \( l \) — Length of the coil (inches)

Explanation: The formula provides an empirical approximation of inductance for single-layer air-core coils with good accuracy (within 1% for coils where length > 0.8r).

3. Importance of Coil Inductance Calculation

Details: Accurate inductance calculation is crucial for designing RF circuits, filters, antennas, and other electronic components where precise inductance values are required.

4. Using the Calculator

Tips: Enter the coil radius in inches, number of turns (must be integer), and coil length in inches. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is Wheeler's formula?
A: An empirical formula developed by Harold A. Wheeler in the 1920s for calculating the inductance of single-layer air-core coils.

Q2: What are the limitations of this formula?
A: It works best for single-layer coils with length > 0.8r. For multilayer coils or very short coils, other formulas should be used.

Q3: Can I use metric units?
A: This calculator uses inches as per the original formula. For metric, convert cm to inches (1 inch = 2.54 cm) before calculation.

Q4: How does wire thickness affect the result?
A: The formula assumes thin wire. For thick wire, use the average radius (between inner and outer radii of the coil).

Q5: What's the typical accuracy of this formula?
A: About 1% for coils where length > 0.8r, and within a few percent for other single-layer coils.