The standard resistor is the bottom value element in our maker field, however additionally it is extremely helpful. Beforehand, we’ve proven find out how to use resistors in a venture, however the focus of this information is knowing the coloured bands which wrap across the heart of the resistor. These resistor colour codes inform us precisely what number of Ohms of present every unit handles.
How will we learn a resistor colour code? Why are some resistor colour codes 4 bands and others 5 bands? What resistor do I want for an LED? We reply all of those questions and provide the instruments to rapidly calculate the right resistor for all your initiatives.
Widespread Resistor Colour Codes and Their Makes use of
| Resistor Sort | 4-Band Colour Code | 5-Band Colour Code | Widespread Makes use of |
|---|---|---|---|
| 100 Ohm | Brown-Black-Brown-Gold | Brown-Black-Black-Black-Gold | LED Mild Safety |
| 220 Ohm | Crimson-Crimson-Brown-Gold | Crimson-Crimson-Black-Black-Gold | LED Mild Safety |
| 330 Ohm | Orange-Orange-Brown-Gold | Orange-Orange-Black-Black-Gold | LED Mild Safety |
| 1K Ohm (1 Kiloohm) | Brown-Black-Crimson-Gold | Brown-Black-Black-Brown-Gold | LED Safety, Voltage Divider |
| 4.7K Ohm | Yellow-Purple-Crimson-Gold | Yellow-Purple-Black-Brown-Gold | Pull-up/down resistor for I2C |
| 10k Ohm | Brown-Black-Orange-Gold | Brown-Black-Black-Crimson-Gold | Pull-up/down resistor |
| 100K Ohm | Brown-Black-Yellow-Gold | Brown-Black-Black-Orange-Gold | Bleed resistor for capacitor |
| 1 Megaohm | Brown-Black-Inexperienced-Gold | Brown-Black-Black-Yellow-Gold | Capacitive contact circuits |
Resistor Colour Code: Fast Reference
Studying Resistor Colour Codes Left to Proper
Resistors haven’t any polarity, to allow them to be utilized in any orientation in a circuit. However to determine the right resistor colour code values we have to perceive the coloured bands on the resistor.
On a typical four-band pastime stage resistor, there are three colours in a gaggle. These are the primary, second important figures and the multiplier. The ultimate band is the resistor’s tolerance, a margin of error if you’ll. For almost all of hobbyists a tolerance of 5% (Gold) is ideal and customary.
We solely want the additional precision if we create delicate circuits, for instance audio and video initiatives. We will at all times spot the tolerance band as it’s the solely band printed on the “shoulder” of the resistor. Search for this band to determine the orientation of the resistor.
A five-band resistor has a further band, a 3rd important determine, which affords a larger stage of accuracy ought to a venture require it. So we’ve three important figures, a multiplier and the tolerance, which is singularly printed on the shoulder.
Tips on how to Learn a Resistor Colour Code
Let’s use a 220 Ohm resistor, which is usually used with LED lights, for example of find out how to learn resistor colour codes.
- The primary important determine is purple, and utilizing the decoder we will see that purple has a worth of two.
- The second important determine can be purple, so that offers us 22.
- The multiplier is brown, and this decodes to 10. If we multiply 22 by 10 we get 220.
- The ultimate band, tolerance, is gold. Gold is 5%, which suggests we will settle for a resistance with a 5% margin of error.
For makers requiring larger precision there are additionally 5 band resistors which have a 3rd important determine. The additional determine supplies readability which will be important in circuits delicate to resistance for instance scientific and engineering devices.
Here’s a 5 band 220 Ohm resistor and its resistor colour code.
- The primary important determine is purple, and utilizing the decoder, we will see that purple has a worth of two.
- The second important determine can be purple, so that offers us 22.
- The third important determine is black, indicating 0. We now have 220.
- The multiplier is black, and this decodes to 1. If we multiply 220 by 1 we get 220.
- The ultimate band, tolerance, is gold. Gold is 5%, which suggests we will settle for a resistance with a 5% margin of error.
100 Ohm Resistor Colour Code
The 100 Ohm resistor is usually used for LED safety. Finest used with white, blue and inexperienced LEDs at 5V. 100 Ohm resistors can be used with different colours however count on the brightness to vary as they aren’t the right worth.
100 Ohm resistors will be recognized by way of the resistor colour code of Brown-Black-Brown-Gold and, for 5 band resistors, Brown-Black-Black-Black-Gold.
220 Ohm Resistor Colour Code
The 220 Ohm resistor is without doubt one of the commonest ones that hobbyists will come throughout, as a result of it’s usually used with LEDs. With out a 220 Ohm resistor, easy LEDs would devour an excessive amount of present and rapidly burn out. We’re utilizing the resistor to restrict the present that the LED can use. (“The sunshine that burns twice as brilliant, burns half as lengthy”). The 220 Ohm resistor will be recognized by way of resistor colour codes of Crimson-Crimson-Brown-Gold or Crimson-Crimson-Black-Black-Gold.
If we have been to make use of a blue LED with a 3.2V ahead voltage (the quantity of voltage wanted to get present to movement throughout a diode) and 10mA ahead present (the utmost protected present you possibly can repeatedly move via the system with out inflicting harm) on a 5V provide we would wish a 180 Ohm resistor. As a substitute we will use a 220 Ohm resistor, 40 Ohms greater so our LED gained’t be as brilliant, however will probably be effectively protected.
330 Ohm Resistor Colour Code
The 330 Ohm resistor can be fairly widespread, being present in starter electronics kits for the Arduino and Raspberry Pi Pico. The 330 Ohm resistor can be a viable candidate for many LEDs however some will begin to look dimmer than others. We will additionally use a 330 Ohm resistor with a buzzer to drop the tone of buzzer from “annoying” to barely much less annoying. Adafruit’s NeoPixel information recommends defending a GPIO pin through the use of a resistor (between 300 and 500 Ohms) between the info pin enter and GPIO of your Raspberry Pi / Arduino.
A 330 Ohm resistor will be recognized by way of resistor colour codes of Orange-Orange-Brown-Gold or Orange-Orange-Black-Black-Gold.
1K Ohm Resistor Colour Code
The 1K Ohm (1 Kiloohm) resistor is often the utmost resistance used for LEDs. Any LED that makes use of a 1K resistor will likely be boring, however will gentle up. The 1K Ohm resistor is usually used to wonderful tune a circuit or pull up/down a knowledge pin. A 1K resistor, together with a 2.2K resistor can be utilized to kind a voltage divider that may drop 5V right down to round 3.4V. That is helpful when utilizing 5V parts on the Raspberry Pi’s 3.3V GPIO.
A 1K Ohm resistor will be recognized by way of resistor colour codes of Brown-Black-Crimson-Gold or Brown-Black-Black-Brown-Gold.
4.7K Ohm Resistor Colour Code
The 4.7K Ohm resistor is beneficial for including a pull-up resistor to the SDA and SCL pins of an I2C system. Adafruit’s Stemma QT boards have this inbuilt, however ought to we use one other model of board, we would wish so as to add a 4.7 Kiloohm resistor to each of these pins. By doing this we assure that the I2C information is accurately and persistently despatched to our system.
A 4.7K Ohm resistor will be recognized by way of resistor colour codes of Yellow-Purple-Crimson-Gold or Yellow-Purple-Black-Brown-Gold.
10K Ohm Resistor Colour Code
The 10K Ohm resistor is commonly used as a pull-up resistor for an enter pin. For instance on Arduinos we will use a 10K Ohm resistor to pull-up an enter pin, in order that when the button is pressed, it pulls the enter pin excessive with 5V, triggering an motion in our code. We used a 10K Ohm resistor to pull-up the info pin on a DHT22 temperature sensor in our earlier resistor reference.
A 10K Ohm resistor will be recognized by way of resistor colour codes of Brown-Black-Orange-Gold or Brown-Black-Black-Crimson-Gold.
100K Ohm Resistor Colour Code
100K Ohm resistors are on the uppermost restrict of what most makers want. This can be a lot of resistance in a small bundle however it has its makes use of. They’re usually used as bleed resistors on a capacitor, to scale back the danger of a nasty zap or to tune a delicate audio / video circuit.
A 100K Ohm resistor will be recognized utilizing the colour code of Brown-Black-Yellow-Gold or Brown-Black-Black-Orange-Gold for a 5 band resistor.
1M Ohm Resistor Colour Code
This can be a lot of resistance and most hobbyists / makers won’t ever want it. We’ve used a 1M Ohm resistor with an Arduino to create a capacitive contact interface (our personal Makey Makey). However most people won’t ever want one. Nonetheless, the 1M Ohm resistor has colour codes of Brown-Black-Inexperienced-Gold or Brown-Black-Black-Yellow-Gold.
A 1M Ohm resistor will be recognized by way of resistor colour codes of Brown-Black-Inexperienced-Gold or Brown-Black-Black-Yellow-Gold.
LED Brightness Resistor Calculator
Now we have a field filled with LEDs, however what are the right resistors for every colour? To work this out we have to use a little bit math and by chance there’s a calculation that we will use.
R is the resistor worth that we’d like for our LED and, to work that out, we have to know the provision voltage (Vs), the ahead voltage (Vf) and the ahead present (If) of the LED. We will study the Vf and If of an LED b referring to its datasheet. If not, here’s a desk of approximate values which can be utilized for normal hobbyist circuits.
Typical LED Ahead Voltages
| LED Colour | Vf Vary (Volts) |
|---|---|
| Crimson | 1.8 – 2.1 |
| Orange / Amber | 1.9 – 2.2 |
| Yellow | 1.9 – 2.2 |
| Inexperienced | 2 – 3.1 |
| Blue | 3 – 3.7 |
| White | 3 – 3.4 |
Here’s a fast resistor and LED reference for 3.3 and 5V microcontrollers.
3.3V LED Resistor Values By Mild Colour
| White | Crimson | Blue | Yellow | Inexperienced | |
|---|---|---|---|---|---|
| Provide Voltage (Vs) | 3.3V | 3.3V | 3.3V | 3.3V | 3.3V |
| Ahead Voltage (Vf) | 3V | 2.2V | 3V | 1.8V | 3V |
| Ahead Present (If) | 20mA | 20mA | 20mA | 20mA | 20mA |
| Resistor Wanted | 150 Ohm | 55 Ohm | 150 Ohm | 75 Ohm | 150 Ohm |
5V LED Resistor Values By Mild Colour
| White | Crimson | Blue | Yellow | Inexperienced | |
|---|---|---|---|---|---|
| Provide Voltage (Vs) | 5V | 5V | 5V | 5V | 5V |
| Ahead Voltage (Vf) | 3V | 2.2V | 3V | 1.8V | 3V |
| Ahead Present (If) | 20mA | 20mA | 20mA | 20mA | 20mA |
| Resistor Wanted | 100 Ohm | 140 Ohm | 100 Ohm | 160 Ohm | 100 Ohm |