How to Convert Millihenries to Microhenries
To convert an inductance measurement from millihenries to microhenries, multiply the inductance value by the conversion factor. Since one millihenry is equal to 1,000 microhenries, you can use this formula:
The inductance in microhenries is equal to the millihenries multiplied by 1,000.
Using the formula: microhenries = millihenries × 1,000
microhenries = 5 mH × 1,000 = 5,000 µH
Therefore, 5 millihenries equals 5,000 microhenries.
How Many Microhenries Are in a Millihenry?
There are 1,000 microhenries in one millihenry.
What Is a Millihenry?
The millihenry (symbol: mH) is a unit of electrical inductance equal to one thousandth (10−3) of a henry. The prefix “milli” denotes a factor of 10−3 in the International System of Units. Millihenries are commonly used for medium-sized inductors in power electronics, audio equipment, and industrial control systems. The inductors in audio crossover networks, which split the audio signal into frequency bands for different speakers, typically have values of 0.1–10 mH. In power electronics, the main energy-storage inductors in DC-DC converters often have values of 0.1–10 mH for lower-frequency designs. Filter inductors used to smooth rectified AC in power supplies typically range from 1–100 mH. Relay coils, solenoid valves, and small electromagnets typically have inductance values of 10–500 mH. The voice coil of a typical loudspeaker has an inductance of 0.5–3 mH, which affects the speaker’s impedance at high frequencies.
One millihenry is equal to:
- 0.001 henries (H)
- 1,000 microhenries (μH)
- 106 abhenries (abH)
- 1.1127 × 10−15 stathenries (stH)
What Is a Microhenry?
The microhenry (symbol: μH) is a unit of electrical inductance equal to one millionth (10−6) of a henry. The prefix “micro” denotes a factor of 10−6 in the International System of Units. Microhenries are the most commonly used inductance unit in electronics. Surface-mount inductors (chip inductors) typically range from 0.01 to 1,000 μH, and most RF circuit inductors fall in the microhenry range. In radio frequency (RF) engineering, inductors in the range of 0.1–100 μH are used in antenna matching networks, filters, and oscillator circuits. In switching power supplies, the main inductor is typically 1–100 μH, depending on the switching frequency and power level. Printed circuit board (PCB) traces also have parasitic inductance, typically about 1–10 nH (0.001–0.01 μH) per centimetre of trace length. While small, this parasitic inductance can cause significant problems in high-speed digital circuits operating at gigahertz frequencies.
One microhenry is equal to:
- 10−6 henries (H)
- 0.001 millihenries (mH)
- 1,000 abhenries (abH)
- 1.1127 × 10−18 stathenries (stH)
Understanding Electrical Inductance Units
Inductance is the property of an electrical conductor by which a change in current flowing through it induces an electromotive force (EMF) in the conductor itself (self-inductance) or in a nearby conductor (mutual inductance). It is one of the fundamental quantities in electromagnetism, along with resistance and capacitance.
The physical basis of inductance is Faraday’s law of electromagnetic induction: a changing magnetic field induces an electric field. When current flows through a conductor, it creates a magnetic field. If the current changes, the magnetic field changes, which induces a voltage that opposes the change in current (Lenz’s law). The ratio of the induced voltage to the rate of current change is the inductance.
Major Unit Families
- SI units: The henry (H) is the SI unit of inductance, with standard metric prefixes: μH (microhenry, 10−6 H), mH (millihenry, 10−3 H), kH (kilohenry, 103 H), MH (megahenry, 106 H), GH (gigahenry, 109 H).
- CGS-EMU: The abhenry (abH) is the inductance unit in the CGS electromagnetic system. 1 abH = 10−9 H = 1 nanohenry. It is a very small unit.
- CGS-ESU: The stathenry (stH) is the inductance unit in the CGS electrostatic system. 1 stH ≈ 8.988 × 1011 H. It is an enormously large unit due to the factor of c² in the conversion.
Inductance in Practice
- Electronic components: Chip inductors: 0.001–1,000 μH. Power inductors: 0.1–100 mH. Transformers: 0.01–100 H.
- Parasitic inductance: PCB traces: ~1 nH/cm. IC bond wires: 1–5 nH. Through-hole vias: 0.5–2 nH.
- Audio equipment: Speaker voice coils: 0.5–3 mH. Crossover network inductors: 0.1–10 mH.
- Power systems: Large power transformers: 0.1–10 H. Reactor coils: 0.01–1 H.
Converting Between Inductance Units
All inductance units measure the same physical quantity, so converting between them is a matter of multiplying by the appropriate conversion factor. For SI prefix conversions, each step is a factor of 1,000. The CGS conversions involve fixed factors: 1 abH = 10−9 H (exact) and 1 stH = c² × 10−9 H (where c ≈ 2.998 × 1010 cm/s).
Tips for Inductance Conversions
- For SI metric conversions (μH, mH, H, kH, MH, GH), each prefix step is a factor of 1,000.
- The abhenry equals exactly 10−9 henries, which is the same as 1 nanohenry (nH). This makes conversion straightforward.
- The stathenry is enormous: 1 stH ≈ 899 billion henries. The conversion factor involves the speed of light squared (c²).
- The ratio of 1 stathenry to 1 abhenry is c² (in CGS units) ≈ 8.988 × 1020. This reflects the fundamental relationship between electrostatic and electromagnetic units.
- Most practical electronic inductors have values between 0.01 μH and 100 mH. Very few components exceed 10 H.
- When reading component datasheets, pay attention to whether the inductance is in μH, mH, or H. A factor-of-1,000 error can be catastrophic in circuit design.
- In RF (radio frequency) circuits, inductance values are typically in the 0.1–100 μH range. In power electronics, they are typically 1–100 mH.
Millihenries to Microhenries Conversion Table
The following table shows conversions from millihenries to microhenries.
| Millihenries | Microhenries (µH) |
|---|---|
| 1 mH | 1,000 |
| 2 mH | 2,000 |
| 3 mH | 3,000 |
| 4 mH | 4,000 |
| 5 mH | 5,000 |
| 6 mH | 6,000 |
| 7 mH | 7,000 |
| 8 mH | 8,000 |
| 9 mH | 9,000 |
| 10 mH | 10,000 |
| 11 mH | 11,000 |
| 12 mH | 12,000 |
| 13 mH | 13,000 |
| 14 mH | 14,000 |
| 15 mH | 15,000 |
| 16 mH | 16,000 |
| 17 mH | 17,000 |
| 18 mH | 18,000 |
| 19 mH | 19,000 |
| 20 mH | 20,000 |
| 21 mH | 21,000 |
| 22 mH | 22,000 |
| 23 mH | 23,000 |
| 24 mH | 24,000 |
| 25 mH | 25,000 |
| 26 mH | 26,000 |
| 27 mH | 27,000 |
| 28 mH | 28,000 |
| 29 mH | 29,000 |
| 30 mH | 30,000 |
| 31 mH | 31,000 |
| 32 mH | 32,000 |
| 33 mH | 33,000 |
| 34 mH | 34,000 |
| 35 mH | 35,000 |
| 36 mH | 36,000 |
| 37 mH | 37,000 |
| 38 mH | 38,000 |
| 39 mH | 39,000 |
| 40 mH | 40,000 |