The purose of starter and choke in tube light circuite,for
start-up the tube lights.
The choke work as a blastand induced 850V to 1100V in
starting,by strarter make and break of the circuite. After
glowing the tube light choke work as inductance and provide
110v to circuite.
WHEN TUBE LIGHT IS SWITCHED ON CURRENT FLOWS IN CLOSED
CIRCUIT BETWEEN, CHOWK,BOTH ELECTRODES OF TUBE AND STARTER.
IN CLOSED CIRCUIT FOR A WHILE SELF INDUCTANCE IS PRODUCED
IN CHOWK AND ABOUT 1000 VOLTS INDUCED ACROSS CHOWK, AT THE
SAME INSTANCE STARTER CONTANCTS BECOM OPEN AND INDUCED
VOLTAGE APPERED AT THE TUBE, AND DUE TO THIS HIGH VOLTAGE
CURRENT STARTS FLOWING FROM THE GAS OF THE TUBE AND TUBE
BECOME BRILLIANT/ GLOWING. AFTER THAT STARTER REMAIN OPEN
CIRCUIT TILL NEXT OPERATION OF TUBE LIGHT, AND CHOWK WORK
AS VOLTAGE DROPING DEVICE UP TO 110 V AC.
starter for breaking & closing circuit with the help of
small relay element and choke for to make a voltage from
230v to 1000v for energise electrons (which are in the
argon gas & mercury)and closing & opening starter helps
voltage build up. according to the above process electrons
collision occurrs .so due to that avalanche breakdown
occuers and due to that more number of electrons
created .so the current flow inside the tube is get
increasing & lighting process takesplaces .if current
rising takesplace continuesly the tube light has to be
blasting.so inorder to avoid the blast we should control
the rising current .that can also be done by choke .so
without choke the tubelight get
if u can't belive me ,u can check that
a capacitor connected in parallel with flourescent lamp is
called starter. to strike a flourescent lamp a sudden
discharge is required in the tube. a starter provides this
initial spark. when a tube light arrangement is connected to
the supply, starter charges, a starter current foows during
this session. on reaching the striking voltage, the starter
discharges and a sudden current flows in the tube ionising
the gas and giving it the glow
The starter is used to have a high starting current just to
ignite or excite the fluorogas inside the tube, (to make
and break). then the choke is used to maintain the required
current needed by the gas to maintain its fluorescence.
This is becuase the supply is AC signal, (max-min-max min)
the choke will store energy during rising of current from
the source, then when the current is going to minimum
swing, the choke relesaes its energy therby giving current
to the lamp, until the next cicle again of rising current
from the AC source, it will store again energy in the form
of magnetic field. ( inductors are used for current
regulator- means it opposes change in current in the
Try to use DC source and you dont need inductor anymore..
thatis why ballast are being replaced now by electronic
ballast, which is actually a rectifier circuit to output
stable DC current going to the fluorescent lamp. the
purpose of this is to eliminate the reactive power received
by the inductor ballast, which save extra KVA capacity of
the electrical system
The choke has two main functions. It (in conjunction with the starter if it has one) causes the tube to ignite by using the back emf to create a plasma in the tube and it controls the current through the tube when it is ignited.
In a gas discharge, such as a fluorescent lamp, current causes resistance to decrease. This is because as more electrons and ions flow through a particular area, they bump into more atoms, which frees up electrons, creating more charged particles. In this way, current will climb on its own in a gas discharge, as long as there is adequate voltage (and household AC current has a lot of voltage). If the current in a fluorescent light isn't controlled, it can blow out the various electrical components.
A fluorescent lamp's ballast works to control this. The simplest sort of ballast, generally referred to as a magnetic ballast, works something like an inductor. A basic inductor consists of a coil of wire in a circuit, which may be wound around a piece of metal. If you've read How Electromagnets Work, you know that when you send electrical current through a wire, it generates a magnetic field. Positioning the wire in concentric loops amplifies this field.
This sort of field affects not only objects around the loop, but also the loop itself. Increasing the current in the loop increases the magnetic field, which applies a voltage opposite the flow of current in the wire. In short, a coiled length of wire in a circuit (an inductor) opposes change in the current flowing through it. The transformer elements in a magnetic ballast use this principle to regulate the current in a fluorescent lamp.
A ballast can only slow down changes in current -- it can't stop them. But the alternating current powering a fluorescent light is constantly reversing itself, so the ballast only has to inhibit increasing current in a particular direction for a short amount of time.
Magnetic ballasts modulate electrical current at a relatively low cycle rate, which can cause a noticeable flicker. Magnetic ballasts may also vibrate at a low frequency. This is the source of the audible humming sound people associate with fluorescent lamps.
Modern ballast designs use advanced electronics to more precisely regulate the current flowing through the electrical circuit. Since they use a higher cycle rate, you don't generally notice a flicker or humming noise coming from an electronic ballast. Different lamps require specialized ballasts designed to maintain the specific voltage and current levels needed for varying tube designs.
Fluorescent lamps come in all shapes and sizes, but they all work on the same basic principle: An electric current stimulates mercury atoms, which causes them to release ultraviolet photons. These photons in turn stimulate a phosphor, which emits visible light photons. At the most basic level, that's all there is to it!
1)we r having one problem .one dry type
transformer(6.6KV/433V)is taking high magnetizing current on
delta connected HV side of "U" phase when compared to other
two phases.could any body tell the reason why it is happening?
2)why CT secondary side protection core has got higher
winding resistance when compared to that of metering core of