# pyTesla - User Documentation

## Table of Contents

- [Overview](#overview)
- [Installation](#installation)
- [Getting Started](#getting-started)
- [Configuration](#configuration)
- [User Interface](#user-interface)
- [Parameter Reference](#parameter-reference)
- [Simulation Types](#simulation-types)
- [Viewing Results](#viewing-results)
- [Profile Management](#profile-management)
- [Troubleshooting](#troubleshooting)
- [Advanced Features](#advanced-features)

---

## Overview

pyTesla integrates FEMM (Finite Element Method Magnetics) and LTspice to provide electromagnetic and circuit analysis for Tesla coil design. The application features a PyQt5-based GUI with real-time visualization capabilities.

### Key Features
- Electromagnetic field analysis using FEMM
- Circuit simulation with LTspice
- Interactive Tesla coil visualization
- Guided simulation workflow
- Profile management for saving designs

---

## Installation

### System Requirements
- Windows operating system
- FEMM 4.2 or higher
- LTspice XVII or higher
- 4GB RAM minimum (8GB+ recommended)
- 1GB free disk space

### Installation Steps

1. **Install Prerequisites**
   - Install FEMM from http://www.femm.info
   - Install LTspice from https://www.analog.com/ltspice
   - LTspice will be automatically detected on first run
   - Manual configuration available via **Config → Settings** if needed

2. **Install pyTesla**
   - **Option 1**: Download and run `pyTesla.exe` (recommended)
   - **Option 2**: For development, clone repository and run `win-install.bat`

3. **Verify Installation**
   - Launch pyTesla
   - pyTesla will automatically detect LTspice installation
   - Confirm FEMM and LTspice integration by running a simple simulation

---

## Getting Started

### Your First Simulation

1. **Launch pyTesla** - The default profile will load automatically

2. **Adjust Parameters**
   - Enter secondary coil dimensions
   - Configure topload parameters
   - Set primary coil parameters
   - Set circuit parameters as needed

3. **Run Basic Simulation**
   - Click the "Lumped" button for a quick simulation
   - Review preliminary results

4. **Run Full Analysis**
   - Click "Distributed" for detailed electromagnetic analysis
   - Click "LTspice Only" for circuit analysis

5. **View Results**
   - Check the bottom panel for calculated values
   - View field plots in the right panel gallery
   - Use the plotter for frequency response analysis

---

## Configuration

### Settings Dialog

Access application settings via **Config → Settings** in the menu bar.

#### LTspice Configuration

pyTesla automatically detects LTspice on startup using multiple strategies:
- Searches AppData\Local\Programs\ADI (LTspice 24+)
- Searches Program Files\ADI and Program Files\LTC (older versions)
- Supports LTspice XVII, LTspice IV, and newer versions

**Manual Configuration:**
1. Open **Config → Settings**
2. Use **Find LTspice** to auto-detect all installations
3. Use **Browse** to manually select LTspice executable
4. Use **Clear** to reset and use automatic detection

**Supported LTspice Versions:**
- LTspice 24+ (newest ADI releases)
- LTspice XVII (widely used version)
- LTspice IV (legacy version)

#### Theme Selection

Choose between Dark and Light themes:
1. Open **Config → Settings**
2. Select theme from **Appearance** section
3. Click **OK** to apply

**Available Themes:**
- **Dark Theme**: Optimized for extended use in low-light environments
- **Light Theme**: Better visibility in bright environments

### Automatic Detection

pyTesla automatically detects:
- **LTspice**: Multiple installation locations and versions
- **FEMM**: Standard installation paths
- **Display Units**: Restores your preferred units from previous session

---

## User Interface

### Main Window Layout

The interface is divided into four main areas:

1. **Left Panel**: Interactive Tesla coil visualization
2. **Center Panel**: Parameter input groups in a scrollable layout
3. **Right Panel**: Image gallery for simulation results
4. **Bottom Panel**: Simulation controls, model selection, and results display

### Model Selection

The application supports two electromagnetic modeling approaches:

- **Lumped Model**: Treats components as single elements - faster but less detailed
- **Distributed Model**: Divides secondary into sections - more accurate for advanced analysis

**Using Model Selection:**
- Radio buttons in the bottom panel allow switching between Lumped and Distributed models
- Buttons are only enabled when corresponding FEMM results are available
- Results display automatically updates to show selected model's data
- Model selection affects both displayed results and LTspice simulations

### Parameter Groups

1. **Secondary Coil**: Dimensions and wire specifications
2. **Topload**: Size, shape and position
3. **Primary Coil**: Type and dimensions
4. **Ferrite Core**: Optional core parameters
5. **Ground Plane**: Ground plane specifications
6. **Strike Rings**: Protective ring configuration
7. **SPICE Inputs**: Circuit simulation parameters
8. **FEMM Inputs**: Field simulation controls and units

### Simulation Controls

- **Lumped**: Fast, lumped-parameter analysis
- **Distributed**: Full electromagnetic analysis
- **LTspice Only**: Circuit simulation using existing FEMM results
- **Voltage Stress**: Analysis for insulation design
- **Parasitic Modes**: Higher-order resonance analysis
- **Plotter**: Interactive frequency response tool

### Button Color System

- **Blue**: Ready to run (prerequisites satisfied)
- **Yellow**: Parameters changed, needs re-simulation
- **Red**: Simulation in progress
- **Green**: Simulation completed successfully

---

## Parameter Reference

### Secondary Coil Parameters

- **Outer Diameter**: External diameter of the wound coil
- **Height**: Vertical height of the winding
- **Base Height**: Distance from ground plane to coil bottom
- **Wire Gauge (AWG)**: Wire diameter selection
- **Wire Insulation**: Additional insulation thickness

### Topload Parameters

- **Major Radius**: Distance from coil center to torus center
- **Minor Radius**: Torus tube radius
- **Number of Rings**: Multiple ring configuration
- **Topload Height**: Position above secondary

### Primary Coil Parameters

- **Primary Type**: Toroidal, Flat Spiral, or Helical
- Dimensions specific to selected type
- Positioning relative to secondary

### FEMM Parameters

- **Units**: Length unit selection
- **Frequency**: Operating frequency for analysis
- **Secondary Sections**: Division count for accuracy vs. speed
- **Mesh Sizes**: Controls simulation accuracy and speed

---

## Simulation Types

### Lumped Simulation

- Quick electromagnetic analysis using lumped-parameter model
- Treats secondary as single inductor (no sectioning)
- Provides preliminary inductance, capacitance, and coupling estimates
- Faster than Distributed simulation, useful for rapid design iteration
- **Note**: Distributed simulation automatically runs lumped first to obtain accurate frequency estimate

### Distributed Simulation

- Comprehensive electromagnetic field analysis using FEMM
- Includes both magnetic and electric field simulations
- Multi-section model for accurate distributed parameter effects
- Required before running LTspice circuit simulations

**Workflow:**
1. **Lumped Pre-Simulation**: Automatically runs lumped simulation first to obtain accurate frequency estimate
2. **Distributed FEMM**: Runs magnetic and electrostatic field simulations at the estimated frequency
3. **LTspice Analysis**: Circuit simulation using distributed transmission line model

**Iteration Mode:**
- When the Distributed button is already green (previous successful run), clicking it again enters iteration mode
- Iteration mode skips lumped and electrostatic simulations, only re-running magnetic + LTspice
- Preserves electrostatic capacitance matrix from previous run for faster convergence refinement
- Useful for manual frequency convergence without resetting all calculations
- Reuses FEMM geometry for optimized performance

### LTspice Circuit Simulation

- AC circuit analysis using FEMM-derived parameters
- Uses the currently selected model (Lumped or Distributed):
  - **Lumped Model**: Simpler circuit with single L and C elements
  - **Distributed Model**: Multi-section transmission line model for accuracy
- Calculates resonant frequencies and impedances
- Provides voltage distribution and phase information
- Model selection affects spark gap simulations and parasitic mode analysis

### Voltage Stress Analysis

**Manual Tool**: Click the **Voltage Stress** button to analyze electric field stress at real operating conditions for insulation design and breakdown prevention.

**How It Works:**
1. **Calculate Operating Voltage**: Uses desired primary current (from SPICE Inputs) to calculate required bus voltage via LTspice
2. **Generate Voltage Profile**: Simulates distributed model at calculated bus voltage and selected pole frequency
3. **Extract Voltage Distribution**: Gets voltage at each secondary section from LTspice (e.g., 4.8kV → 133kV gradient)
4. **FEMM Field Analysis**: Applies voltage profile to FEMM electric field model and solves for E field
5. **Stress Visualization**: Displays electric field magnitude (V/m) scaled to 3 MV/m (air breakdown threshold)

**Key Features:**
- Uses **real operating voltages** based on primary current, not arbitrary 1V reference
- Includes effects of **spark loading** and **parasitic modes** on voltage distribution
- Shows **E field magnitude** in V/m, not absolute voltage
- Red areas indicate high stress approaching **3 MV/m breakdown field**
- Helps identify insulation weak points and optimize strike ring placement

**Requirements:**
- Distributed FEMM simulation must be completed first
- Pole frequency must be selected
- Primary current value in SPICE Inputs

**Practical Use:**
- Design strike ring placement to protect high-stress regions
- Verify insulation safety margins at operating conditions
- Understand how spark loading shifts stress patterns via parasitic modes

**Note**: This analysis runs only when manually requested via the Voltage Stress button, not automatically during distributed simulation.

### Parasitic Modes Analysis

- Identifies higher-order resonances beyond primary/secondary poles
- Shows mode shapes and frequencies for each resonance
- Efficient implementation: draws FEMM geometry once, updates voltages for each mode
- Useful for optimizing coil geometry and understanding multi-mode behavior
- Requires Distributed simulation and LTspice results

---

## Viewing Results

### Results Panel

The bottom panel displays key simulation results based on the selected model:

**Model Selection Controls:**
- Radio buttons to switch between Lumped and Distributed models
- Only enabled when corresponding FEMM results are available
- Results automatically update when switching models

**Displayed Results (vary by selected model):**
- **Inductance Values**: Primary, secondary, and mutual inductance
- **Capacitance**: Topload and distributed capacitance
- **Coupling**: Coupling coefficient (k-factor)
- **Resonant Frequencies**: Primary and secondary resonances
- **Wire Data**: Length, turns, and resistance
- **Model Label**: Shows "LUMPED MODEL" or "DISTRIBUTED MODEL" for clarity

### Image Gallery

The right panel contains simulation visualizations:

- **Magnetic Field Plots**: Field lines and flux density
- **Electric Field Plots**: Equipotential lines and field intensity
- **Frequency Response Plots**: Frequency response charts
- **Mode Shapes**: Parasitic mode visualizations

### Interactive Plotter

The plotter provides advanced frequency response analysis with a comprehensive preset system for repeatable test scenarios.

#### Opening the Plotter

Click the **Plotter** button in the simulation controls after running FEMM simulations. The plotter window is independent and can be resized or moved to a second monitor.

**Important**: The plotter does not automatically run simulations on startup. You must manually click **Compose & Analyze** to run your first simulation. This prevents startup hangs from problematic simulation parameters and gives you control over when simulations execute.

#### Circuit Configuration

Configure the circuit being analyzed:

- **Input Voltage**: Choose between 1V reference or calculated input voltage
- **MMC Capacitors**: Set primary and secondary MMC values (µF and pF)
- **Resonator Model**: Select between models:
  - **Lumped**: Single-element model (formerly called Simple)
  - **Distributed**: Multi-section model (formerly called Complex)
  - Automatically uses the main window's selected model when syncing
- **Spark Load**: Choose from saved sparks, current GUI values, parametric R load, or none
- **Sync with Main**: Pull current values and model selection from the main window

#### Analysis Presets

Reusable SPICE directives for different analysis types:

**Built-in Presets:**
- **Standard sweep**: Linear frequency sweep (1kHz-500kHz, 1000 points) for AC analysis
- **Trans**: Transient analysis with sinusoidal excitation for ringdown waveforms
- **fft**: Pulse excitation with parametric frequency for FFT spectrum analysis

**Managing Presets:**
1. Edit the **SPICE Directives** text area (supports multi-line)
2. Click **Add to Presets** to save
3. Click **Update Preset** to modify existing
4. Click **Delete Preset** to remove

**Supported Directives:**
- `.ac lin/dec/oct <points> <start> <end>` - AC frequency sweep
- `.tran <tstop> <tstart> <tstep>` - Transient analysis
- `.step param <name> <start> <end> <step>` - Parametric sweep
- `.meas AC <name> <measurement>` - AC measurements
- Voltage/current sources (V1, I1, etc.) for transient excitation
- Multiple directives per preset (newline-separated)

#### Transient Analysis Modes

The plotter supports both frequency-domain (AC) and time-domain (transient) analysis:

**Time Domain Analysis:**
- Uses `.tran` directives to simulate waveforms over time
- Supports various excitation types: SINE, PULSE, PWL (piecewise linear), user-defined
- Useful for analyzing ringdown behavior, spark breakout, and transient response
- Example: `V1 vin 0 SINE(0 250 386k)\n.tran 0 1000us 0 100n`

**FFT (Frequency Spectrum) Analysis:**
- Applies Python-based FFT (Fast Fourier Transform) to transient simulation results
- Shows complete frequency spectrum, not just harmonics
- Uses Hanning window to reduce spectral leakage
- Ideal for analyzing harmonic content, resonant peaks, and frequency distribution
- Example: Use PULSE excitation with parametric frequency for broadband analysis

**Selecting Analysis Mode:**
- **AC Analysis**: Select "ac" in analysis_mode, use `.ac` directives
- **Transient (Time Domain)**: Select "transient" in analysis_mode with "time_domain" display mode
- **Transient (FFT)**: Select "transient" in analysis_mode with "fft" display mode
- Plot configurations automatically set the correct modes

#### Measurements

Add voltage, current, or calculated measurements to plot:

**Quick Add:**
- Select signal from **Available Signals** dropdown
- Click **→ Add** to insert into custom measurement field

**Custom Formulas:**
- Simple traces: `V(top)`, `I(L1)`, `V(n001)`
- Multiplication: `V(top)*I(R_load)` (power)
- Division: `V(n001)/I(L1)` (impedance)
- Numeric constants: `V(top)*1000`, `I(L1)/0.001`

**Managing Measurements:**
- **Add Measurement**: Add custom formula to plot
- **Remove Selected**: Delete selected measurement
- **Clear All**: Remove all measurements at once

#### Measurement Presets

Predefined sets of measurements for common analysis tasks:

**Built-in Presets:**
- **Power Analysis**: Topload voltage, load current, and power
- **Voltage Distribution**: Voltage at coil sections (s0, s5, top)
- **Input Analysis**: Primary voltage, current, and impedance

**Managing Measurement Presets:**
1. Add desired measurements to the list
2. Click **Save as Preset**
3. Select preset from dropdown to instantly load all measurements

#### Plot Configurations

Complete analysis workflows that combine circuit setup, analysis directives, and measurements:

**Built-in Configurations:**

*Spice Analysis Configurations:*
- **Power Sweep (Rval)**: Parametric load resistance sweep to find optimal power transfer
- **Frequency Response**: Standard frequency sweep (100kHz-1500kHz) with input current measurement
- **Voltage Distribution**: Voltage at all 10 coil sections across extended frequency range (100kHz-3500kHz)

*Transient Analysis Configurations:*
- **Transient - Time Domain**: Ringdown analysis with sinusoidal excitation and realistic spark load (24" spark)
- **Transient - FFT Example**: Pulse excitation for harmonic analysis with parametric frequency (36" spark)

**Using Plot Configurations:**
1. Select configuration from **Saved Configuration** dropdown
2. Plot automatically updates with the complete preset scenario
3. All circuit settings, directives, measurements, and display modes are applied

**Creating Configurations:**
1. Configure circuit settings (voltage, MMC, resonator model, spark load)
2. Set analysis directive (`.ac` for AC, `.tran` for transient)
3. Add measurements to plot
4. Set analysis_mode ("ac" or "transient") and display_mode ("time_domain" or "fft")
5. Click **Save Current Setup** to save as reusable configuration

**Benefits:**
- **Repeatability**: Exact same test every time
- **Documentation**: Named scenarios for reports
- **Comparison**: Quickly switch between AC and transient analysis types
- **Realistic Defaults**: Transient configurations include appropriate spark loads and excitation

#### Enhanced Hover System

Interactive data inspection with comprehensive value display:

**Features:**
- **Crosshairs**: Vertical and horizontal reference lines on both magnitude and phase plots
- **Multi-Line Display**: Shows values from ALL plotted measurements at once
- **Frequency/Parameter Detection**: Automatically detects sweep type (frequency vs. parametric)
- **Phase Integration**: Displays both magnitude and phase values in single tooltip
- **Smart Positioning**: Tooltip avoids plot edges for visibility

**Using Hover:**
- Move mouse over plot area to see values at that X-axis position
- Tooltip shows frequency/parameter value and all measurement values
- Values snap to actual data points for accuracy

#### Plot Controls

Customize plot appearance:

- **Show Phase**: Toggle phase plot visibility
- **Logarithmic Frequency**: Log scale for frequency axis (auto-set for DEC/OCT sweeps)
- **Logarithmic Magnitude**: Log scale for magnitude axis
- **Use dB for Magnitude**: Convert magnitude values to decibels

#### Workflow Examples

**Example 1: Resonant Frequency Analysis (AC)**
1. Load **Frequency Response** plot configuration
2. Click **Compose & Analyze**
3. Hover over peak to find exact resonant frequency
4. Export plot using toolbar save button

**Example 2: Load Power Optimization (Parametric)**
1. Load **Power Sweep (Rval)** configuration
2. Ensures parametric R load is selected
3. Plots power (V×I) vs. resistance
4. Find peak for optimal load matching

**Example 3: Ringdown Analysis (Transient - Time Domain)**
1. Load **Transient - Time Domain** plot configuration
2. Verify circuit parameters and spark load selection
3. Click **Compose & Analyze** to run transient simulation
4. View time-domain waveform showing exponential decay and oscillation
5. Analyze ringdown time and damping behavior

**Example 4: Harmonic Analysis (Transient - FFT)**
1. Load **Transient - FFT Example** plot configuration
2. Check parametric frequency matches your operating frequency
3. Click **Compose & Analyze** to run transient simulation
4. FFT automatically computed and displayed as frequency spectrum
5. Identify resonant peaks and harmonic content
6. Hover over peaks to read exact frequencies and amplitudes

**Example 5: Custom Analysis**
1. Set circuit parameters (voltage, MMC values, spark load)
2. Create custom directive:
   - AC: `.ac lin 1000 200k 400k`
   - Transient: `V1 vin 0 SINE(0 250 386k)\n.tran 0 500us 0 50n`
3. Add measurements: `V(top)`, `V(n001)/I(L1)`, `V(top)*I(R_load)`
4. Set analysis_mode and display_mode as appropriate
5. Save as plot configuration for reuse

#### Tips for Effective Use

- **Sync Before First Plot**: Click **Sync with Main** to pull current circuit values and model selection
- **Manual Workflow**: Plotter does not auto-run - verify parameters before clicking "Compose & Analyze"
- **Use Presets for Repeatability**: Save commonly-used configurations as plot presets
- **AC vs Transient**: Use AC analysis for frequency response, transient for time-domain behavior
- **FFT for Spectrum**: Use transient simulation with FFT display mode to see complete frequency content
- **Parametric Sweeps**: Use `.step param` for sweeping component values (R, L, C, frequency)
- **Multi-Line Formulas**: Hover shows ALL measurements - no need to hover individual lines
- **Save Plots**: Use toolbar save button - defaults to profile's images directory
- **Realistic Spark Loads**: Transient configurations use appropriate spark models for accurate results

---

## Profile Management

### Saving Profiles

- **File → Save Coil Profile**: Save current design
- All parameters, results, and images are saved
- Profiles are stored in the `profiles/` directory

### Loading Profiles

- **File → Load Coil Profile**: Load saved design
- Previous simulation results are restored
- Button states reflect the profile's simulation status

### Profile Structure

```
profiles/
├── [profile_name]/
│   ├── [profile_name].json    # Configuration file
│   ├── [profile_name].log     # Session log
│   ├── images/                # Simulation plots
│   ├── femm/                  # FEMM files (.fem, .fee)
│   └── ltspice/               # LTspice netlists and results
│       └── sparks/            # Saved spark configurations
```

---

## Troubleshooting

### Common Installation Issues

- **FEMM Not Found**: Ensure FEMM is installed and in system PATH
- **LTspice Not Detected**:
  - Go to **Config → Settings**
  - Click **Find LTspice** to auto-detect installations
  - If not found, use **Browse** to manually select LTspice.exe
  - Check common locations:
    - `C:\Users\[YourName]\AppData\Local\Programs\ADI\LTspice\`
    - `C:\Program Files\ADI\LTspice\`
    - `C:\Program Files\LTC\LTspiceXVII\`
- **Startup Error**: Check file permissions and ensure profiles directory is writable

### Simulation Problems

- **FEMM Convergence Error**: Adjust mesh size or geometry
- **LTspice Errors**: Check for invalid parameter values
- **Memory Issues**: Reduce section count or mesh density

### Results Issues

- **Missing Results**: Verify simulation completed successfully
- **Image Display Problems**: Check profile directory permissions
- **Unexpected Values**: Confirm parameters are in valid ranges

---

## Advanced Features

### Spark Modeling

- Dual-capacitance spark model (C_mutual and C_shunt)
- Phase optimization for streamer analysis
- "Calculate Spark Values" tool with frequency convergence algorithm:
  - Iteratively optimizes spark resistance for actual operating frequency
  - Maximum 5 iterations with 1000 Hz tolerance
  - FEMM calculates capacitance matrix with spark geometry
  - LTspice determines actual pole frequency with spark load
  - Convergence guarantees R matches resonant frequency
- Auto-save calculated sparks to library with generated names
- Load/save spark configurations for repeatable testing

### Matrix-Based Analysis

- Multi-section secondary modeling
- Accurate capacitance matrix calculations
- Captures distributed parameter effects

### Unit System

- Change display units via FEMM Inputs panel
- All measurements automatically convert
- Supported units: inches, mm, cm, m, mils, ft

### Themes

pyTesla includes professional themes designed for optimal readability:

- **Dark Theme**: Default theme optimized for extended use in low-light environments
- **Light Theme**: High-contrast theme for bright environments

**Changing Themes:**
1. Go to **Config → Settings**
2. Select desired theme in the **Appearance** section
3. Click **OK** to apply immediately

Theme preference is saved automatically and restored on next launch.

### Controller Library

pyTesla includes a controller template system for DRSSTC and interrupter simulations:

**Library Location:**
- `library/controllers/` directory (next to executable)
- Auto-created on first run if missing
- Located at project root in development mode

**Template Format:**
- SPICE netlist files with `.net` extension
- First comment line becomes dropdown description in Circuit Analyzer
- Complete netlists with parameter documentation in comments
- Users can add custom templates by placing `.net` files in directory

**Using Templates:**
1. Open the Plotter (Circuit Analyzer)
2. Select template from controller dropdown
3. Click insert button to add to SPICE directives
4. Modify parameters as needed for your design

**Note:** The library directory is created automatically but not pre-populated. Users can create custom controller netlists or obtain templates from the Tesla coil community.

### Button State Intelligence

pyTesla uses an intelligent button state tracking system to minimize unnecessary re-simulations:

**Color-Coded States:**
- **Blue** (Normal): Ready to run, prerequisites satisfied
- **Yellow** (Warning): Parameters changed since last run, needs re-simulation
- **Red** (Running): Simulation currently in progress
- **Green** (Success): Simulation completed successfully

**Parameter Snapshots:**
- Stores "known good" parameters when simulation succeeds
- Automatically compares current parameters against snapshot
- Debounced checking (100ms delay) prevents excessive validation
- Only triggers re-simulation warnings when parameters actually change

**Sequential Invalidation:**
- **Geometric changes** (coil dimensions, topload, etc.): Invalidate all simulations
- **Circuit changes** (MMC, primary current, etc.): Only invalidate LTspice, stress, and modes
- **Frequency changes**: Only invalidate distributed magnetic simulation
- Preserves valid downstream results when possible, saving computation time

This intelligent system ensures you always know which simulations are current and helps optimize your workflow by avoiding redundant calculations.

---

## Tips for Effective Use

### Workflow Optimization

1. **Initial Design Exploration**:
   - Use standalone "Lumped" simulation for rapid parameter exploration
   - Provides quick frequency and coupling estimates for initial design iterations

2. **Full Distributed Analysis**:
   - Click "Distributed" button (automatically runs lumped first for accurate frequency estimate)
   - Generates distributed transmission line model with capacitance matrix
   - Both Lumped and Distributed results become available for comparison

3. **Manual Convergence Refinement**:
   - After successful distributed simulation (green button), adjust frequency manually if needed
   - Click "Distributed" again to enter iteration mode
   - Iteration mode skips lumped and electrostatic, only refining magnetic + LTspice
   - Repeat as needed for convergence without resetting expensive calculations

4. **Model Selection**:
   - Use Lumped model for:
     - Quick frequency checks
     - Basic coupling analysis
     - Simple circuit analysis
   - Use Distributed model for:
     - Accurate voltage distribution
     - Parasitic mode analysis
     - Spark gap optimization
     - Final design validation

5. **Performance Tips**:
   - Group parameter changes before running time-consuming simulations
   - Use iteration mode for frequency refinement without full re-simulation
   - Save known-good designs as profiles for reference
   - Choose appropriate section count for Distributed model:
     - 10 sections: Standard analysis (default)
     - 20+ sections: High precision needs

*© pyTesla Documentation - For Tesla coil design and simulation*