Part of the Electronics glossary:

The henry (symbolized H) is the Standard International ( SI ) unit of inductance . Reduced to base SI units, one henry is the equivalent of one kilogram meter squared per second squared per ampere squared (kg ­ m 2 ­ s -2 ­ A -2 ).

In a circuit where the current is changing at a constant rate of one ampere per second (A/s), an inductance of 1 H results in the generation of one volt (1 V) of potential difference across an inductor. More rapid current changes produce much greater surges of electromotive force. This is the principle by which a spark coil generates a high and dangerous voltage.

The henry is a large unit of inductance. In audio-frequency ( AF ) and radio-frequency ( RF ) applications, units of millihenrys (mH), where 1 mH = 10 -3 H, and microhenrys (µH), where 1 µH = 10 -6 H, are common. Occasionally, the filter choke in a power supply, or a field coil designed to produce a large voltage upon release of its stored magnetic energy, will be found whose value can be expressed in henrys. In very-high-frequency ( VHF ), ultra-high-frequency ( UHF ), and microwave devices and systems, units of nanohenrys (nH), where 1 nH = 10 -9 H, and picohenrys (pH), where 1 pH = 10 -12 H, are used.

Also see capacitor , inductor , reactance , and farad .

This was last updated in March 2011
Posted by: Margaret Rouse

Related Terms

Definitions

  • geo-fencing (geofencing)

    - Geo-fencing is a feature in a software program that uses the global positioning system (GPS) or radio frequency identification (RFID) to define geographical boundaries. A geofence is a virtual barr... (WhatIs.com)

  • bandwidth

    - Definition: Learn what bandwidth is and how the term is used as a synonym for signal frequency range, data transfer rate and capacity. (SearchEnterpriseWAN.com)

  • quad-core processor

    - A quad-core processor is a chip with four independent units called cores that read and execute central processing unit (CPU) instructions such as add, move data, and branch. (WhatIs.com)

Glossaries

  • Electronics

    - Terms related to electronics, including definitions about electrical components and words and phrases about computers, laptops parts, digital cameras, televisions and home appliances.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question About henry (H)Powered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.