High frequency inductive lamp and power oscillator

Patent · Fri Dec 31 23:00:00 EST 1999

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

/315/313/
100
70
915
active
active element
alignment
apart
aperture
applied
applied thereto
appropriately
approximates
bulb
capable
ceramic
circuits
coil
composite
comprising
conductive
conductive surface
configuration
configured
control
control circuit
control circuits
coupled
cup
current
cylindrical conductive
defined
device
device capable
driving
driving frequency
effective
efficiency
electrical
electrodeless
electrodeless lamp
element
employed
encased
excitation
excitation coil
features
flanged
formed
forms
frequencies
frequency
half
half wavelength
head
head comprising
helmholtz
inductive
inductively
inductively coupled
insulating
insulating ceramic
integrally
integrally formed
integrated
lamp
length
loops
management
match
matrix
matrix composite
metal
metal matrix
mhz
non-helical
novel
oscillator
parallel
plurality
power
power oscillator
pre-formed
preferably
provides
providing
reflective
rf
rf power
semi-cylindrical
shape
single
solid-state
spaced
spaced apart
structural
surface
surrounding
therethrough
thereto
thermal
thermal management
tuning
utilizes
various
various control
watts
wavelength
wedding