LITERATURE REVIEW

JOURNAL 3

RESISTOR

The resistor is a passive electrical component to create resistance in the flow of electric current. In almost all electrical networks and electronic circuits they can be found. The resistance is measured in ohms. An ohm is the resistance that occurs when a current of one ampere passes through a resistor with a one volt drop across its terminals. The current is proportional to the voltage across the terminal ends. 

Resistors can be divided in construction type as well as resistance material. The following breakdown for the type can be made: 

• Fixed resistors 
• Variable resistors, such as the: 
• Potentiometer 
• Rheostat 
• Trimpot 

• Resistance dependent on a physical quantity: 
• Thermistors (NTC and PTC) as a result of temperature change 
• Photo resistor (LDR) as a result of a changing light level 
• Varistor (VDR) as a result of a changing voltage 
• Magneto resistor (MDR) as a result of a changing magnetic field 
• Strain Gauges as a result of mechanical load

Credit to : Prajapati Dipali, K., Raj Roshani, D., Patel Komal, C., & Hilali Marhaba, A. ( 2014). Automatic Gate Opening System For Vehicles With RFID or Password.