Electronics - Resistor Colour Codes.

Select Colour Code:

The resistor has a number of coloured bands. The first three identify the resistance value and the last usually the fourth identifies the tolerance.

Select the colour codes from the pull down boxes below to match the resistor and its value will be displayed.

Resistor Band 1:	Black Brown Red Orange Yellow Green Blue Violet Gray White
Resistor Band 2:	Black Brown Red Orange Yellow Green Blue Violet Gray White
Multiplier Band 3:	Black Brown Red Orange Yellow Green Blue Violet Gray White
Tolerance Band 4:	Brown (±1%) Red (±2%) Green (±0.5%) Blue (±0.25%) Violet (±0.1%) Gray (±0.05%) Gold (±5%) Silver (±10%)

Resistor Value:

Resistor Value: 0 Ω, Tol ±20%

---

LED Current Limiting Resistor:

An LED will require a resitor to limit the current flowing through it. Enter the Supply voltage, LED Forward Voltage, and LED Forward Current. The forward voltage is often dependant on the colour of the LED a table below provides typical values based on the LED colour. The typical value for forward current is around 20mA. This is regardless of colour type. However the data sheets for the particular selected device should be consulted!


Enter the values to calculate the Resistor value required and the Power.

Supply Voltage: (Vs):	V
LED Forward Voltage: (Vf):	V
LED Forward Current: (If):	mA

Resistor Value
Resistor Value:	ohms
Power:	W

Calculate

---

RC Circuit Delay Time Calculator:

A Resistor and Capacitor in series will pulse at a time that can be calculated as a product of the voltage and capacitance.

Enter the values to calculate the time constant values are in Ohms and µFarads.

Resistor Value: (Ohms):	V
Capacitor Value: (µF):	V

Delay Time

Delay Time: 0 seconds

Calculate

---