To make connections of a Fluorescent lamp wiring and to study the accessories of the same

Aim

To make connections of a Fluorescent lamp wiring and to study the accessories of the same

Apparatus Required:

Circuit Diagram:

Theory:

To make connections of a Fluorescent lamp wiring and to study the accessories of the same

1. The Electrode of the starter which is enclosed in a gas bulb filled with argon gas, cause discharge in the argon gas with consequent heating

2. Due to heating, the bimetallic strip bends and causes in ihe starter to close, After this, the choke, the Filaments (Tube ends) to tube and starter becomes connected in series

3. When the current flows through the tube end filaments the heat is produced. Dining the process theDischarge in Lin: starter tube disappears and the contacts in the starter move apart.

4. When sudden break in the circuit occur due to moving apart of starter Terminals, this causes a high value of e.m.f to be induced in the choke.

5. According; to Lenz's law. the direction of induced e.m.f. in the choke will try to opose the fall of current in the circuit.

6. The fluorescent lamp is a low pressure mercury lamp and is a long evacuated tube. IT contains a small amount of mercury and argon gas at 2.5 mm Pressure. At the time of switching in the rube, mercury is in the form of small drops. Therefore, to start the tulie, filling up of argon gas is necessary. So, in the beginning, argon gas starts burning at die ends of die tube; tlie mercury is heated and controls the current and the tube starts giving light. At each end of tlie tub, there is a tungsten Electrode which is coated with fast electron emitting material. Inside of the tube is coated with phosphor according to the type of light.

7. A starter helps to start the start the tube and break the circuit.

8. The choke coil is also called blast. it has a laminated core over which enameled wire is wound. The function of the choke is to increase the voltage to almost 1000V at the time of switching on the tuhe and when the tube starts working, it reduces the voltage across the tube and keeps the current constant.

Procedure:

1. Give the connections as per the circuit diagram.
2. Fix the tube holder and choke in the tube.
3. The phase wire is connected to the choke and neutral directly to the tube
4. Connect the starter in series with the tube.
5. Switch on the supply and check Hie fluorescent lamp lighting.