Plasmatronics
Encyclopedia
Plasmatronics was a company, founded by former Air Force Weapons Laboratory (now Phillips Laboratory) scientist Dr. Alan E. Hill, which produced a plasma speaker
design. This was first demonstrated at the 1978 Winter Consumer Electronics Show
.
The product was effectively a loudspeaker
with an integrated amplifier
; however, it used a gas plasma
, sourced from a helium tank in the back of the unit, as a near-massless driver
. The plasma driver only reproduced the higher frequencies as a tweeter
; the lower frequencies used a conventional woofer
driver.
While praised for accurate sound reproduction at demonstrations, the system had a number of disadvantages, including high cost, and the periodic handling of heavy compressed helium
cylinders. Although widely rumored to have produced corrosive ozone
, the high temperature discharge actually destroys the gas. There were, however, other unidentified by-products of the discharge with a distinctive odor.
Plasma speaker
Plasma speakers are a form of loudspeaker which varies air pressure via a high-energy electrical plasma instead of a solid diaphram. Connected to the output of an audio amplifier, plasma speakers vary the size of a plasma glow discharge, corona discharge or electric arc which then acts as a...
design. This was first demonstrated at the 1978 Winter Consumer Electronics Show
Consumer Electronics Show
The International Consumer Electronics Show is a major technology-related trade show held each January in the Las Vegas Convention Center, Las Vegas, Nevada, United States. Not open to the public, the Consumer Electronics Association-sponsored show typically hosts previews of products and new...
.
The product was effectively a loudspeaker
Loudspeaker
A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...
with an integrated amplifier
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...
; however, it used a gas plasma
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
, sourced from a helium tank in the back of the unit, as a near-massless driver
Transducer
A transducer is a device that converts one type of energy to another. Energy types include electrical, mechanical, electromagnetic , chemical, acoustic or thermal energy. While the term transducer commonly implies the use of a sensor/detector, any device which converts energy can be considered a...
. The plasma driver only reproduced the higher frequencies as a tweeter
Tweeter
A tweeter is a loudspeaker designed to produce high audio frequencies, typically from around 2,000 Hz to 20,000 Hz . Some tweeters can manage response up to 65 kHz...
; the lower frequencies used a conventional woofer
Woofer
Woofer is the term commonly used for a loudspeaker driver designed to produce low frequency sounds, typically from around 40 hertz up to about a kilohertz or higher. The name is from the onomatopoeic English word for a dog's bark, "woof"...
driver.
While praised for accurate sound reproduction at demonstrations, the system had a number of disadvantages, including high cost, and the periodic handling of heavy compressed helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
cylinders. Although widely rumored to have produced corrosive ozone
Ozone
Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...
, the high temperature discharge actually destroys the gas. There were, however, other unidentified by-products of the discharge with a distinctive odor.