 Learn more Important Information about Resistors Today

There are fixed, variable, and physical quality resistors. They are also different categories of resistors depending on the material that has been used to make it such as carbon composition, carbon film, metal film, thick and thin film, foil, or wire wound to resist electricity. There are many other applications of resistors beside the common reason of using them to resist the electric current. Large resistors enable the stored kinetic energy to be released; hence they are used as electric power brakes in trains. They are essential in generating heat, matching, and loading circuits, dividing voltage, fixing time constraints, and controlling gain. They are efficient sources of power for LEDs and blower motors. Resistors have been discussed in details below.

You can identify a resistor using color-coding. The colored bands on the resistor represent its resistance and tolerance values. Most resistors have four colored bands. The colored bands cannot e removed because they are integrated into the body of the resistor. The resistance value is represented by the digits that are on the first two bands. The third band represents the multiplying factor (which determines the resistance value). The tolerance value of the resistor is engraved on the last band.

Colored bands cannot fit on small resistors like the SMDs; therefore, color-coding is not a reliable method of identifying resistors in some cases. A numeric based code is used on an SMD instead of the colored bands. All SMD resistors are of the same size; hence the manufacturing process is standardized for all of them using the rapid-fire pick-and-place machines.

Use the following tips when you are in need of a resistor, and you are considering purchasing one. Use a standard formula and Ohm’s Law to find out the resistance level of the resistor because it should meet your needs. Find out your voltage and current for you to be able to calculate the resistance level of the resistor. The second step is to calculate the power rating of the resistor. The power rating of the resistor is the level of power it will be dissipating. You can use the example below to calculate the power rating where P (power in Watts), V (voltage drop across the resistor), and R (resistance of the resistor in Ohms). Your LED has a 4V voltage, the resistor has a 200 Ohm value, and the power supply is 10V. The amount of power that the resistor will dissipate is: 10V – 4V = 6V. 6V is the voltage drop and this answer is applied further as P = 6V*6V / 200 Ohm = 0.18 Watts. After obtaining the resistance and power rating values, pick a standard resistor that will dissipate the amount of power that you need.