Resistor Calculators
A comprehensive suite of calculators for resistor calculations
4-Band Color Code
Calculate resistance value from 4-band color codes, commonly used in general purpose resistors
5-Band Color Code
Calculate resistance value from 5-band color codes, used in precision resistors
6-Band Color Code
Calculate resistance value from 6-band color codes, including temperature coefficient
SMD Code Calculator
Convert SMD codes to resistance values for surface mount resistors
Series Calculator
Calculate total resistance in series
Parallel Calculator
Calculate total resistance in parallel
Power Rating Calculator
Calculate power dissipation and rating
Temperature Calculator
Calculate temperature effects on resistance
Voltage Divider
Design voltage divider circuits
Current Shunt
Calculate shunt resistor values for current measurement
LED Current Limiter
Calculate current limiting resistor values for LED circuits
Pull-up/Pull-down
Calculate appropriate values for pull-up and pull-down resistors
Quick Reference
Ohm's Law
Power Calculation
Series Connection
Parallel Connection
Design Guidelines
Power Rating
- •Always use resistors rated at least 2x the calculated power
- •Consider temperature derating factors
- •Account for ambient temperature effects
Temperature Considerations
- •Check the temperature coefficient
- •Consider thermal management
- •Allow for adequate ventilation
Tolerance Selection
- •Use 1% for precision applications
- •5% is suitable for general purpose
- •Consider cost vs precision requirements
Application Notes
Voltage Divider
Design considerations for voltage dividers
- •Consider loading effects
- •Account for power dissipation
- •Choose appropriate resistor values
Pull-up/Pull-down
Guidelines for pull-up and pull-down resistors
- •Consider input impedance
- •Calculate power consumption
- •Choose appropriate resistance values
Current Sensing
Best practices for current sensing applications
- •Use low-value precision resistors
- •Consider power rating carefully
- •Account for self-heating effects
Troubleshooting
Common Issues
- •Incorrect resistance reading
- •Overheating problems
- •Tolerance issues
Best Practices
- •Regular resistance measurement
- •Thermal imaging inspection
- •Proper ventilation
Safety Considerations
- •Never exceed voltage rating
- •Ensure proper cooling
- •Use appropriate safety margins
Frequently Asked Questions
Color Code Reading
Basic Color Code
Understanding the basics of resistor color codes
- First band indicates first digit
- Second band indicates second digit
- Third band is the multiplier
- Fourth band indicates tolerance
Power and Temperature
Power Rating
Understanding power ratings and temperature effects
- Power rating at room temperature
- Temperature derating
- Maximum operating temperature
Circuit Applications
Common Applications
Common resistor applications in circuits
- Voltage division
- Current limiting
- Pull-up/pull-down configurations
Selection Guidelines
Selection Criteria
Guidelines for selecting appropriate resistors
- Power rating considerations
- Tolerance requirements
- Temperature coefficient needs