| |
M1BYT > LIGHTS 15.12.04 19:30l 54 Lines 2395 Bytes #999 (0) @ WW
BID : 883217M1BYT
Read: GUEST
Subj: Re: Fluorescent Lights.
Path: DB0FHN<DB0THA<DB0ERF<DB0HGW<ON0DXC<ON0RET<DB0RES<ON0AR<7M3TJZ<HG8LXL<
ON4HU<GB7YFS<GB7FCR
Sent: 041215/1725Z @:GB7FCR.#16.GBR.EU #:26307 [Blackpool] FBB-7.03a $:883217M1
From: M1BYT@GB7FCR.#16.GBR.EU
To : LIGHTS@WW
ZR2ACJ Opined with considerable skill:-
> Eg:1. What does the transformer do and why?
It is not a tranformer, it is a ballast or choke. Initially it provides a high
voltage pulse as the starter opens to start the tube (a little like a car
ignition coil), then limits the flow of current after it has ignited.
> 2. What is the funtion of the Capacitor in the circuit?
Usually power factor correction. As the light will be an inductive/reactive
load, it will have a power factor which is best corrected at the load. Lots of
similar fittings without the correction capacitor would provide a very
inefficient load on the supply.
> 3. How does it work, and what is the funtion of the Starter?
This shorts out the tubes such that the filaments are directly across the
mains. The choke, one end filament, the starter then the other filament form a
series circuit. The starter when cold forms a short circuit, which makes the
heaters glow. As the starter warms up, it goes open circuit switching off the
heaters and causing a high voltage to be presented across the tube and
(hopefully) its ignition. Once ignited the starter can be removed and the
light will continue to function.
> 4. Why has the tube got two filaments?
To warm both ends of the tube and when the tube is running, as an electrode at
each end of the tube. If the room is warm enough, the tube can be struck
without need for heaters or starter. If the tube is only turned off briefly,
it can be reignited without the starter installed.
Electronic ballasts do not make use of the heaters, except as electorodes.
ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ»
º 73 from Harry, M1BYT @ GB7FCR.#16.GBR.EU º
ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͹
º International Museums Weekend 18th+19th June 2005 º
º www.ukradioamateur.org/imw/index.html º
ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͹
º The ARC's FL/RAE courses + Newcomers Introduction º
º to amateur radio:- http://www.ukradioamateur.org/ º
ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍËÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͹
º QTH: Garforth, W. Yorks.. º Timed 15:16 º
º harry.m1byt@tiscali.co.uk º 02 Dec 2004 º
ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÊÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ
Message sent using WinPack-Telnet V6.80
Read previous mail | Read next mail
| |
