Yotech Engineering

Saturday, October 13, 2018

Standard Resistor Values and Color

Components and wires are coded with colors to identify their value and function.

Image result for how to read a resistor and resistor colour code

The colors brown, red, green, blue, and violet are used as tolerance codes on 5-band resistors only. All 5-band resistors use a colored tolerance band. The blank (20%) “band” is only used with the “4-band” code (3 colored bands + a blank “band”).

Example #1

A resistor colored Yellow-Violet-Orange-Gold would be 47 kΩ with a tolerance of +/- 5%.

Example #2

A resistor colored Green-Red-Gold-Silver would be 5.2 Ω with a tolerance of +/- 10%.

Example #3

A resistor colored White-Violet-Black would be 97 Ω with a tolerance of +/- 20%. When you see only three color bands on a resistor, you know that it is actually a 4-band code with a blank (20%) tolerance band.

Example #4

A resistor colored Orange-Orange-Black-Brown-Violet would be 3.3 kΩ with a tolerance of +/- 0.1%.

Example #5

A resistor colored Brown-Green-Grey-Silver-Red would be 1.58 Ω with a tolerance of +/- 2%.

Example #6

A resistor colored Blue-Brown-Green-Silver-Blue would be 6.15 Ω with a tolerance of +/- 0.25%.

Preferred Values or E-series

To make mass manufacturing of resistors easier, the IEC (International Electrotechnical Commision) defined tolerance and resistance values for resistors in 1952. These are referred to as preferred values or E-series, published in standard IEC 60063:1963. Capactors, Zener diodes, and inductors also use these standards.

The purpose of this was so that when companies produce resistors with different values of resistance, they would equally space on a logarithmic scale. This helps the supplier with stocking different values. Resistors produced by different manufacturers are compatible for the same designs because of the use of standard values.

Standard Resistor Value Series and Tolerances

The standard E3, E6, E12, E24, E48 and E96 resistor values are listed below.

*The calculated tolerance for this series is 36.60%, While the standard only specifies a tolerance greater than 20%, other sources indicate 40% or 50%.

E3 Resistor Series

These are the most widely used resistor series in the electronics industry.

E6 Resistor Series

E12 Resistor Series

E24 Resistor Series

E48 Resistor Series

how to test a transistor

Step 1: Materials

Well I had most of these materials on had so this project did not cost me a dime but if your lucky like me I'm sure you could get everything for under $5 if you scavenge for old components. Everything here is cheap and should be found locally in old electronics except for the 9 volt battery which I happen to have a case of. However the case was made out of bendable plastic sheets that I got from my art class if your creative you can make the case out of anything.

Stuff Needed:

LED of any color
9 volt battery
bendable material to make the case
3-4 pin socket for transistor
10k ohm resistor
470 ohm resistor
NPN transistors
Small Switch

Step 2: Testing

Before any electronic project goes to soldering or finalization you should always check with a breadboard that everything is working and that all the components are fine. This 5min check could save you from frustration later on after spending show much time soldering it to together to find out that your contraption doesn't even work.

Step 3: Construction

Now we will start of by soldering the components together just follow the circuit that has been attach and you will continue on until your done. You can choose to do it on a circuit board but for simplicity sake I just did it with out a circuit board and positions the joints in a way that wont allow for short circuits win place in their casing.

The transistor circuit I found was used as a way to learn transistors I just modified the circuit by allowing the transistor to be removable therefore leading to the circuit now becoming a transistor tester.

Step 4: Casing

I made the case by first printing out the scaled up template I designed for a portable use. I printed out the sheet and then laid it below the plastic material. I basically traced out the case with an knife, and then glued it back up together with hot melt.

Okay at this point I hot melt the circuit components in to pre-cut openings and I was constantly checking the connections to make sure everything was in order by having the transistor in the place lighting up the LED the whole the time. You would hate for a fault in the wiring after you closed everything back up with hot melt.

Step 5: YAY Finish

Okay that's it and everything should be in order now. This is first in a series of instructables that are soon to come.
Thank you for your time and if you have any comments feel free to tell me.