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CONSTANT POWER LAMP POWER SUPPLY

IP.com Disclosure Number: IPCOM000022985D
Original Publication Date: 1976-Jun-30
Included in the Prior Art Database: 2004-Mar-27
Document File: 2 page(s) / 390K

Publishing Venue

Xerox Disclosure Journal

Abstract

The impedance of multi-alkaline and gas discharge lamps varies widely due to impurities~ uneven mixture proportions pressure variations etc. In order to maintain the output of the lamp relatively constant, it is necessary to main- tain constant electrical power into the 1amp~ The power supply shown in the figure constantly monitors both the voltage across the lamp and the current to the lamp and controls the input power supply to provide a constant pre- set power level regardless of the static and dynamic variations of the lamps The dynamic variation is referred to as the impedance variation due to the operating temper-- ature variation of lamps~

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Page 1 of 2

XEROX DISCLOSURE JOURNAL

CONSTANT POWER LAMP POWER
SD PPLY
Shingo Arase

Proposed Classification
U*S~ C1~ 315/149
Into Cl, H05b 37/02

The impedance of multi-alkaline and gas discharge lamps
varies widely due to impurities~ uneven mixture proportions
pressure variations etc. In order to maintain the output
of the lamp relatively constant, it is necessary to main-
tain constant electrical power into the 1amp~ The power
supply shown in the figure constantly monitors both the
voltage across the lamp and the current to the lamp and
controls the input power supply to provide a constant pre-
set power level regardless of the static and dynamic
variations of the lamps The dynamic variation is referred
to as the impedance variation due to the operating temper--
ature variation of lamps~

The power supply provides a voltage range of 300 to 600
volts at output Eo to handle the wide variation of lamp
impedance during the warm-up cycle. The supply also pro--
vides a high voltage across the lamp (1000 volts) which is
required to ignite the lamp.

Volume 1 Number 6 June 1976 73

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Page 2 of 2

CONSTANT POWER LAMP POWER SUPPLY (Cont~d)

Referring to the figure, a pulsewidth modulation (PwM)
technique was used to regulate the power to the lamp. The
size ana weight of the transformer 8 required is reduced by
an order of magnitude by operating with 20 Khz, A free
running oscillator 10 generates the master control signal
(40 Khz) This 40 Khz signal is fed into phase splitter
12 and provides complimentary square waves which are...