A resistor is a limiter of the electrical current that flows through a circuit. Resistance is the restriction of current. Often in a resistor the electrons that pass through the resistor are changed to various kinds of energy. The most common forms of energy that electrons are converted to are heat and light. For example, in a light bulb there is a resistor made of tungsten which converts the electrons into light.
Series and Parallel[change | change source]
Resistors can be linked in various combinations to help make a circuit:
- Series - Where the resistors are linked one after another.
- Parallel - Where the resistors are linked over one another.
There are many different types of resistors. Not only do some have a higher resistance to electricity than others, but resistors also have different ratings to tell electricians how much power they can handle before they break, and how accurately they can slow the flow of electricity.
Nowadays electrical industry in many cases uses so called surface-mount technology based resistors which can be be very small.
Color code[change | change source]
Resistor's values are rated by the colors that are listed on the side of the resistor. The colored bands that are used on the sides of a resistor are black, brown, red, orange, yellow, green, blue, purple, gray, and white. Each color represents a different number. The black band represents the number 0, brown band represents the number 1, red is 2 and so on all the way to white which is the number 9. These numbers are very important in the electronic field.
A resistor can have multiple bands of color on its side. The most common have four but they can range all the way up to 6 per resistor. On a four band resistor, the last band is gold or silver. Hold this band on the right side, and read the colors from left to right. The first two bands are read as the numbers that they represent in the color code. The third band acts as a multiplier for the other bands, so for example, if the third band was a yellow band which is a 3, it would mean you multiply the two numbers by 1000. In short you add the value of the color in zeros at the end, so add three zeros.
Resistor Materials[change | change source]
There are many different types of resistors you can find. They are all made with a resistance material encased in a non-conductive material casing, such as plastic. Fixed resistors are usually made of carbon encased in a plastic cylinder, with a connecting wire on either end. Most resistors used in electronics today are carbon resistors. Older resistors were made of a poorly conducting metal, in order to restrict the flow of electricity.
References[change | change source]
- "what's a resistor". http://www.qrg.northwestern.edu/projects/vss/docs/thermal/3-whats-a-resistor.html. Retrieved 20 May 2012.
- "series and parallel circuts". http://physics.bu.edu/py106/notes/Circuits.html. Retrieved 20 May 2012.
- "Resistor Color Code". http://www.warren-wilson.edu/~physics/physics1/ActivityGuides/currentVoltage/ColorCode.html. Retrieved 20 May 2012.
- "resistor and capacitor values". http://www.swarthmore.edu/NatSci/echeeve1/Ref/Resistor/resistor.html. Retrieved 20 May 2012.
- "resistors". http://www.longwood.edu/staff/meshejianwk/electronics/announcements/ResistorLab.pdf. Retrieved 20 May 2012.
- "carbon resistors". http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/rescarb.html. Retrieved 20 May 2012.
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