# Standard Values and Recognition Factor

The standard values for inductors employ the same numerical multipliers used with resistors and inductors. Like the capacitor, the most common employ the same numerical multipliers as the most common resistors, that is, those with the full range of tolerances (5%, 10%, and 20%).
In general, therefore, expect to find inductors with the following multipliers: $0.1 \mu H$, $0.12 \mu H$, $0.15 \mu H$, $0.18 \mu H$, $0.22 \mu H$, $0.27 \mu H$, $0.33 \mu H$, $0.39 \mu H$, $0.47 \mu H$, $0.56 \mu H$, $0.68 \mu H$, $and 0.82 \mu H$, and then $1 mH$, $1.2 mH$, $1.5 mH$, $1.8 mH$, $2.2 mH$, $2.7 mH$, and so on.
Figure 1 was developed to establish a recognition factor when it comes to the various types and uses for inductors — in other words, to help the reader develop the skills to identify types of inductors, their typical range of values, and some of the most common applications. Figure 1 is certainly not all-inclusive, but it does offer a first step in establishing a sense for what to expect for various applications.
Type: Open Core Coil
Typical Values: 3 mH to 40 mH
Applications: Used in low-pass filter circuits.
Found in speaker crossover networks
Type: Toroid Coil
Typical Values: 1 mH to 30 mH
Applications: Used as a choke in AC
power lines circuits to filter transient
and reduce EMI interference. This
coil is found in many electronic
appliances.
Type: Hash Choke Coil
Typical Values: 3 H to 1 mH
Applications: Used in AC supply
lines that deliver high currents.
Type: Delay Line Coil
Typical Values: 10 H to 50 H
Applications: Used in color
televisions to correct for timing
differences between the color
signal and black and white signal.
Type: Common Mode Choke Coil
Typical Values: 0.6 mH to 50 mH
Applications: Used in AC line filters,
switching power supplies, battery
charges and other electronic equipment.
Type: RF Chokes
Typical Values: 10 H to 50 H
television, and communication
circuits. Found in AM, FM, and
UHF circuits.
Type: Moiled Coils
Typical Values: 0.1 H to 100 H
Applications: Used in a wide variety
of circuit such as oscillators, filters,
pass-band filters, and others.
Type: Surface Mounted Inductors
Typical Values: 0.01 H to 100 H
Applications: Found in many
electronic circuits that require
miniature components on
multilayered PCB.