What are the types of resistor?

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Resistor has many types including CFR, MFR, MOR and many more special types. In this blog we are going to see what are those types and why is the necessity for that particular type to be present in market.  In my last blog I explained about what is a resistor and the formula calculation (not the color code calculation).If you want to see that you can click My first blog about resistor definition and formula

Table of contents:
  • Type of resistor
  • Description about each type.
  • Reason why the type is available still in market (even when the upgraded one is  available)

Types of resistor:

Type of resistor by it's package:
  1. Surface mount type (SMD)
  2. Through hole type (TH)
Before getting into the SMD type (only few types are there according to no. of bands), we'll see the types of through hole resistors.

Types of resistor by it's resistance value:
  1. Fixed resistors
  2. Variable resistor (example- potentiometer, rheostat).
Types in fixed resistors:
  1. Carbon film resistor (CFR)
  2. Carbon compound resistor (CCR)
  3. Metal film resistor (MFR)
  4. Metal Oxide resistor (MOR)
  5. Wire wound resistor (WWR)
    • Inductive wire wound resistor
    • Non inductive wire wound resistor
  6. Thick film and thin film resistor
  7. Special resistor
Refer the below image for quicker understanding.

Carbon compound resistor:

Many sources exclude this type of resistor from explanation because this is too old type. These were popularly used before 1960's. This resistor can withstand high energy pulses. But because of it's poor temperature co-efficient and high noise, nowadays rarely we'll be able to see this in applications. Even the datasheet says it can operate from -40 to 150°C, we have to derate from 70°C

Carbon film resistor: 

Construction:

Carbon film resistors are made of ceramic substrate and carbon film. The carbon film is deposited on a ceramic substrate in a helical shape. The different values are attained by changing the width of adjacent carbon film layer and also by the amount of carbon film deposited. 
Sample for CFR type
If you are in a market and confused which one is CFR and MFR this will help you to identify. CFR and MFR types are familiar by it's shape but mostly CFR will be in yellow color background and MFR will be in BLUE color background.

Advantages:

  • Cheap in cost. 
  • Less in size. 
  • Compared to CCR better stable performance in high temperature and less noise.

Disadvantage:

  • The tolerance range is more compared to MFR. Generally 5% of tolerance will get in market, 1% also available but not as easy as 5%. 
  • The reason many people in electronics saying that MFR is better than CFR, not for the tolerance, just for the stability in resistance value. 

Metal Film Resistors:

Metal Film resistors temperature co-efficient are better compared to CFR. Main reason for this, is it's construction.

Construction:

The metal film resistor is quite similar to the carbon film resistor. Instead of a carbon layer substrate, a metal film layer is used as a substrate. Due to this metal film, basically MFR resistors have more stability in resistance compared to CFR resistors.

Advantage:

  • Cheap in cost. 
  • Less in size. 
  • Compared to CCR and CFR, better stable performance in high temperature and less noise.

Disadvantage:

  • Cost is little bit higher in range of higher power ratings.

Metal Oxide Resistors (MOR):

Metal Oxide Resistors are widely used for higher power (0.25W to 4W).

Construction:

The MOR resistor is containing metal oxide element. This metal oxide is a compound of tin oxide and other oxigan atoms.

Advantages:

  • High stability under high temperature.
  • Low cost even high power rating.

Disadvantage:

  • Large in size.

We will see about special resistor in my next blog. For my previous blog, visit  https://eeetronics.blogspot.com/2020/07/resistor.html






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