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DC2FR > INFO 08.07.02 22:13l 38 Lines 1739 Bytes #999 (0) @ WW
BID : 872DB0GV02C
Read: DB0FHN GUEST
Subj: RE: Compact fluorescent lamps (W0RLI)
Path: DB0FHN<DB0ZWI<DB0CHZ<OK0PKL<DB0MRW<DB0PV<DB0FSG<DB0GAP<DB0KFB<DB0CZ<
DB0GV
Sent: 020708/1955z @:DB0GV.#HES.DEU.EU [Frank4t/Mtl OP:DF5FF] DB19c1 $:872DB0GV
From: DC2FR @ DB0GV.#HES.DEU.EU (Wolfgang)
To: INFO @ WW
Hello Hank and all other interested packeteers,
yes of course - compact fluorescent lamps have been very popular
since a couple of years I think all over the world.
Here in Europe f. e. they came into use since about 20 years.
The first types introduced by Philips in the early 80`s were called
"SL lamps", already with conventional choke ballasts and glowstarter
inside.
But soon, fully electronical solutions were developed and came onto
the market. Designed for 220-240v ac operation, they are available
from 5 to abt. 25 watts and mostly have the same principal circuit:
Mains voltage is rectified and smoothed to obtain a 300 v DC inter-
mediate voltage. With this, a self-oscillating series half bridge
inverter is supplied, operating at about 40 kHz. Lamp is connected
to the transistor inverter via a miniature choke, stabilizing the
lamp current at the designed operation frequency and arc voltage
(usually between 30 and 110 v rms).
Transistors are driven by auxiliary windings of a current trans-
former, to ensure that always only one of the two series-connected
inverter transistors is conducting. For preheating and starting the
lamp, a capacitor is used in parallel to the lamp, in connection to
the operating inductivity forming a series resonant circuit to
generate a high starting voltage after filament heating.
So - this in shortform explaining the function of 230 vac designed
compact fluorescent lamps. Don`t know how principal circuitry of
115 vac operated lamps is ...
Voltage doubler instead of bridge rectifier ?
Full-bridge transistor inverter ?
Lower lamp voltages thus higher lamp currents ?
73 de Wolfgang, DC2FR @ DB0GV, Frankfurt - Germany
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