Inductance Converter

About Inductance Converter

Inductance is an electrical property that describes the ability of a component or circuit to oppose changes in current by producing an induced voltage. Inductance is most commonly associated with coils and inductors, where electrical energy can be stored in a magnetic field. The SI unit of inductance is the henry (H).

In practical electronic circuits, one henry is often a relatively large value, so smaller metric units are frequently used. These include the millihenry (mH), microhenry (µH), nanohenry (nH), and picohenry (pH). The metric prefixes indicate powers of ten, allowing the same physical quantity to be expressed conveniently at different scales.

An inductor resists rapid changes in current because a changing current produces a changing magnetic field, which in turn induces a voltage. The induced voltage acts in a direction that opposes the change in current. This behavior is fundamental to inductors used in filters, power supplies, transformers, oscillators, switching circuits, and many other electronic systems.

The magnitude of the induced voltage depends on both the inductance and how quickly the current changes. A component with greater inductance produces a greater induced voltage for the same rate of change of current. This makes inductance an important design parameter when controlling current changes in electrical circuits.

Inductance is used across a wide range of applications. Power electronics may use inductors to smooth current and store energy, while radio-frequency circuits often use relatively small inductances to tune resonant circuits and filter signals. Automotive electronics, audio equipment, telecommunications, motor-control systems, and switching power supplies also commonly use inductive components.

Inductance Units

The calculator uses the henry as its internal reference unit. Every entered value is first converted to henries and then converted into the requested target unit. This provides a consistent conversion method regardless of which two units are selected.

Metric Prefixes for Inductance

The prefixes used with the henry follow the standard metric system. A millihenry is one thousandth of a henry, a microhenry is one millionth, a nanohenry is one billionth, and a picohenry is one trillionth of a henry.

How the Inductance Converter Works

The conversion process uses the henry as a common reference. First, the entered measurement is multiplied by the conversion factor associated with its original unit to obtain a value in henries. The value in henries is then multiplied by the factor required to express it in the selected target unit.

For example, when converting millihenries to microhenries, the calculator uses the relationship between these two metric scales:

Inductance and Changing Current

The electrical behavior of an ideal inductor can be described by the relationship between voltage, inductance, and the rate of change of current.

In this equation, V is voltage in volts, L is inductance in henries, and di/dt is the rate at which current changes with time. The equation shows why an inductor can oppose rapid changes in current.

If the current changes more rapidly, the induced voltage becomes larger for the same inductance. Likewise, increasing the inductance increases the induced voltage for a given current change.

Energy Stored in an Inductor

An inductor stores energy in its magnetic field while current flows through it. The stored energy depends on the inductance and the square of the current.

Here, E represents stored energy in joules, L represents inductance in henries, and I represents current in amperes. Because current is squared, increasing current can significantly increase the amount of energy stored in an ideal inductor.

Common Applications of Inductance

Inductors are used in many electrical and electronic applications. In power supplies, they can smooth current and help regulate the transfer of energy. In filters, inductors can be combined with capacitors and resistors to control which frequencies are allowed to pass through a circuit.

In radio-frequency and communication circuits, small inductors can form resonant networks used for frequency selection and tuning. Inductors are also found in electromagnetic interference filters, DC-DC converters, motor-control circuits, audio equipment, and energy-storage systems.

Choosing the Appropriate Unit

The appropriate inductance unit depends primarily on the size of the component or circuit. Larger inductances can be expressed in henries or millihenries, while many electronic components are specified in microhenries. High-frequency and RF components may have values in nanohenries, with extremely small parasitic inductances sometimes described in picohenries.

Example Conversion

Suppose an inductor has a value of 10 mH and you want to express the same inductance in microhenries.

Therefore, 10 mH = 10,000 µH. The physical inductance has not changed; only the unit used to represent the measurement has changed.

Important Consideration

The value shown by an inductance converter represents a mathematical unit conversion. The actual inductance of a physical component can vary with operating conditions such as frequency, current, temperature, magnetic-core characteristics, and construction. Component datasheets may therefore specify additional electrical characteristics beyond the nominal inductance value.

For general calculations and unit conversions, however, the metric relationships between H, mH, µH, nH, and pH are fixed. This converter uses those standard relationships to provide equivalent inductance values across the supported units.