In an Effort to practice decoding/reading resistors I built a web app that will generate random resistors. The objective is to become fluent reading resistors without memorizing possible combinations, so the values might not be what you would encounter in real life, but completely random.
But how do I read a resistor ?
Its a simple matter, first you need to recognize the stripe colors and their value. Resistors have stripes that match the colors of the rainbow and each stripe has a numeric value and a multiplayer value, you can see these values in the table below:
| Color | 1st band | 2nd band | 3rd band | Multiplier |
|---|---|---|---|---|
| black | 0 | 0 | 0 | 1 |
| brown | 1 | 1 | 1 | 10 |
| red | 2 | 2 | 2 | 100 |
| orange | 3 | 3 | 3 | 1000 |
| yellow | 4 | 4 | 4 | 10000 |
| green | 5 | 5 | 5 | 100000 |
| blue | 6 | 6 | 6 | 1000000 |
| violet | 7 | 7 | 7 | |
| grey | 8 | 8 | 8 | |
| white | 9 | 9 | 9 | |
| gold | 0.1 | |||
| silver | 0.01 |
Reading four stripe Resistors:
On a four stripe resistor we will only focus on the first three stripes, and we will read it as: concat the first two stripes numeric value then multiply by the multiplier of the third stripe.
Example:
These stripes are orange with a value of 3, black with a value of 0, and brown with a multiplier of 10 so we can say 3 & 0 is 30 multiplied by 10 = 300, so this resistor is a 300 Ohm resistor.
Reading a five stripe Resistor:
On a five stripe resistor we will focus on the first four stripes and we will read it as: concat the first three stripes numeric value then multiply by the multiplier on the fourth stripe.
Example:
These stripes are white with a value of 9, grey with a value of 8, green with a value of 5 and brown with a multiplier of 10 so we can say 9 & 8 & 5 = 985 * 10 = 9850 Ohm
Last stripe:
The last stripe is the Tolerance and it does not play a part of the resisted app so I will not go into details.
So now that you got theory, Time to practice