All types of resistors have their own resistor symbols which are used when a circuit diagram is drawn. This page will explain the different standards which are used for resistor symbols and display the most common symbols.
Several standards exist, which describe how the different components should be displayed. In the past a lot of countries or even industries used their own standards, which can be confusing. Nowadays the IEC 60617 standard is international standard for these electronic symbols. However the local standards are still used from time to time. In general, the ANSI standard is still common in the United States. Some examples of standards which describe resistor symbols:
Sometimes the symbol for a particular device is different when it is used in another field of application. Other symbols are used in electronics then for example in architecture and buildings. On top of this, many local deviations from the international standards exist. The following table shows the most common resistor symbols for electronics design.
|Type||Abbreviation||IEC (International)||ANSI (US)|
|Photo resistor or Light dependent resistor||LDR|
|Varistor or Voltage dependent resistor||VDR
|Magneto resistor or Magnetic dependent resistor||MDR|