It may be the most brilliant way of illuminating our houses
and it’s in use till date. Yes, I am are talking about
fluorescent lights, which offer a more energy efficient
means of lighting our homes and offices. Wonder why they hum?
- Learn how they work here.
In the mid-1930s when first fluorescent tube lights were
introduced in the market, they were a total revelation.
People were amazed to see their houses lit as brightly as
cool daylight. These tube lights immediately replaced the
age old “hot” incandescent bulbs and to date are still the
major way of lighting our cities.
- What’s Inside a Fluorescent Tube Light?
A fluorescent lamp basically consists of a long glass gas
discharge tube. Its inner surface is coated with
phosphorous and is filled with an inert gas, generally
argon, with a trace of mercury.
The tube is then finally sealed at low pressure with two
filament electrodes each at its both ends.
These electrode filaments are used to preheat the tube
and initiate a rapid conduction of electrons between the
two end electrodes. The process initially requires a
relatively high amount of power.
The bombardment of these electrons on the inner
phosphorous coating is instantly transformed into a
visible bright light, when we ultimately find the tube
Once the conduction of electrons between the electrodes
is complete, no more heating of the filaments is required
and whole system works at a much lower current.
HOW DOES IT FUNCTION
From the circuit diagram above, we have seen the components of the fluorescent.
*Choke – The choke is in fact a large inductor. It consists of a long
copper winding over iron laminations.
*An inductor by nature always has a tendency to throw
back the stored current in it, every time the power
through it is switched OFF. This principle of the choke is
exploited in lighting a fluorescent tube light.
*When an AC voltage is applied to a tube light fixture, the
voltage passes through the choke, the starter, and the
filaments of the tube.
*The filaments light up and instantly warm up the tube.
The starter holds the current for a moment and then
releases to break the circuit.
*This forces the choke to” kick back” it’s stored current,
which again passes through the filaments and ignites the
*If the tube does not sufficiently charge up, subsequent
kicks are delivered by the choke due to rapid switching of
the starter, so that finally the tube strikes.
*After this the choke only acts like a low impedance
current limiter to the tube as long as the light is kept
written by Anthony aka Tonisage