Resistors

A resistor is a current limiting device. That is to say, it slows down current in an electronic circuit. There is not a circuit in existance that contains zero resistance. Zero resistance is actually viewed as a Short. Ever accidently touch both battery terminals with a screw driver and see sparks fly? Well, Thats what would happen to a electronic circuit with NO resistance...And the device that limits this current is called a RESISTOR. Resistors come in many forms. The most popular, made of carbon, and of metal oxide have color bands on them to indicate the value of the resistor. Resistor values are measured in quantities called OHMs, and denoted with the Greek Omega symbol. The higher the ohmic value, the more current the resistor will limit. Below shows a pictorial of a resistor, and the meaning of the color bands:

0 BLACK 1 BROWN 2 RED 3 ORANGE 4 YELLOW 5 GREEN 6 BLUE 7 VIOLET 8 GREY 9 WHITE

 In the above example, the resistor shown equals a 260 Kilo Ohm resistor. This is because the 1st color band is RED. According to the resistor color code chart on the left, RED equals a 2. So the 1st value is a 2. The second color band is BLUE. Blue equals a 6. So the second number is a 6. So far we are satisfied with the 1st two digits 26. Now, the third digit is the multiplier color band. This is really the number of zeros to add to the end of the first two digits, 26. Because the third color band is YELLOW, the multiplier is the number 4. This means add 4 zeros to the first two digits, 26. Now we have 260000 Ohms.

In electronics, You want to present numbers the smallest way possable without changing the numbers actual value. To do this, You simply move the decimal point to the left in multiples of three, and denote the numbers Engineering notation value. If we move the decimal point to the left 3 places, we are now in the Kilo spot. (Kilo=1000) Before we moved the decimal point, we were at STANDARD NOTATION. This is why the above resistor equals 260 Kilo or K Ohms. (See Below Number Line.)