Basic Electronics

Calculators

• Graphical Resistance Calculator - Choose band colors to calculate resistance
• 555 Timer Calculator - Calculate astable frequency/duty cycle
• Better 555 Calculator - More comprehensive but requires download
• Capacitor Energy Storage - Calculate joules, very useful for coilguns
• Volts/Watts to Amps Converter
• Frequency/Wavelength Calculator - Convert between cm⁻¹, nm, mS/μS/nS
• RLC Simulator - Good for coilgun calculations
• Inductance Calculators - For different coil types
• PCB Trace Width Calculator - ANSI standard
• Ohm’s Law Calculator - For resistance dividers, voltage drops, etc.
• Ohm’s Law Calculator (Alternative)
• Transistor Base Resistor Calculator

Java Applications

• Physics & Math Applets - Useful Java applets for science and physics
• Circuit Examples - Interactive circuit simulations

Datasheets and Information

• DatasheetCatalog - Comprehensive semiconductor datasheets
• AllDatasheet - Alternative datasheet source
• Frank’s Electron Tube Data - Vacuum tube datasheets
• Vacuum Tube Datasheets - Another tube datasheet resource
• IGBT Application Note - Comprehensive IGBT guide (PDF)
• Wire Size Chart - AWG, mm, inches, and current capacity
• National Semi SMPS Guide - Switch mode DC-DC converters
• Maxim Power Circuit App Notes - By purpose or topology
• Maxim DC-DC PSU Cookbook - Quick reference designs

Miscellaneous Electronics

• Tube Amplifier Schematics - Italian site, use Google Translate
• Duncan Amps - Amplifiers, simulation programs, and database
• 101 Science Radio - Information on PLLs, televisions, and more
• Technical Books Online - Scanned electronics books

Tesla Coils

Calculators

• Deep Fried Neon - MMC calc, resonant freq, cap-to-transformer matching
• ClassicTesla/JavaTC - JavaTC and JavaMMC calculators
• MMC Calculator - For SGTC, DRSSTC and QCW

Information

• Richie Burnett’s Site - Solid state and spark gap Tesla coil theory, induction heaters
• Tesla Downunder - Comprehensive Tesla coil information
• Good/Bad Capacitors List - MMC capacitor recommendations
• TC Formulas - Tesla coil calculations and formulas
• DRSSTC Design Guide - Component selection walkthrough

High Voltage

• HV DC Probe - DC-only high voltage probe design
• HV AC Probe - AC high voltage divider

Other Useful Resources

General Calculators

• 1728.com - Miscellaneous calculators for all sorts of things
• cm to inches converter - Remember: 1mm = 0.1cm
• MPH to KPH converter

Coilgun Resources

• Barry’s Coilgun Site - Includes useful Java applications

Software

• Electronics Assistant - Freeware application (mentioned by user 101111)

Useful Formulas

Toroid Wire Length Formula

Length of wire (in feet) for N turns around a toroid:

Length = (T × (OD - ID + 2×H) + (ML / 2.54)) / 12

Where:

• T = number of turns
• OD = outer diameter (inches)
• ID = inner diameter (inches)
• H = height (inches)
• ML = mean length (centimeters)

Toroid Surface Area Formula

Surface area in square centimeters:

Area = π × (OD + ID) × H + (π × (OD/2)² - π × (ID/2)²)

Where all dimensions are in centimeters.

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This compilation was created by the 4hv.org community to help new members with calculations and reduce repetitive questions. Contributions from users including Arcstarter, Chris Cristini, Dr. Slack, aonomus, Shaun, big5824, Mads Barnkob, 101111, Myke, and others.

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