High frequency inductive lamp and power oscillator

Patent · Sat Jan 01 00:00:00 EST 2000

OSTI ID:873338

MacLennan, Donald A ^[1]; Turner, Brian P ^[2]; Dolan, James T ^[3]; Kirkpatrick, Douglas A ^[4]; Leng, Yongzhang ^[2]

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1. Gaithersburg, MD
2. Damascus, MD
3. Frederick, MD
4. Great Falls, VA

A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and/or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

• Research Organization: Fusion Lighting, Inc., Rockville, MD (United States)
• DOE Contract Number: FG01-95EE23796
• Assignee: Fusion Lighting, Inc. (Rockville, MD)
• Patent Number(s): US 6137237
• OSTI ID: 873338
• Country of Publication: United States
• Language: English

Related Subjects

frequency
inductive
lamp
power
oscillator
inductively
coupled
electrodeless
excitation
coil
effective
electrical
length
half
wavelength
driving
applied
thereto
preferably
100
mhz
915
configured
non-helical
semi-cylindrical
conductive
surface
shape
wedding
frequencies
current
forms
loops
spaced
apart
parallel
appropriately
approximates
helmholtz
configuration
utilizes
bulb
encased
reflective
ceramic
cup
pre-formed
aperture
defined
therethrough
structural
features
alignment
flanged
thermal
management
head
integrated
comprising
metal
matrix
composite
surrounding
insulating
integrally
formed
novel
solid-state
provides
rf
single
active
element
device
capable
providing
70
watts
efficiency
various
control
circuits
employed
match
plurality
tuning
thermal management
electrodeless lamp
control circuits
applied thereto
integrally formed
metal matrix
inductively coupled
control circuit
spaced apart
rf power
matrix composite
active element
device capable
power oscillator
driving frequency
head comprising
conductive surface
various control
insulating ceramic
half wavelength
excitation coil
cylindrical conductive
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