Thursday, September 25, 2014

Modified CFL


Re use of burnt out CFL

Modified 20W CFL with Tube Light
             Normally the filament of the CFL’s will be burnt out due to aging, it doesn’t mean that whole CFL is not usable you can reuse it.

Case 1:
The electronic ballast inside CFL may good, then you can replace the outer florescent tube with new one easily available in the market. It depends upon the wattage of the CFL you have.

 To open the CFL you need to insert screw driver in the slot of the plastic casing and rotate it, if screw driver slips then increase the depth of slot by hawkshaw blade. Once you open the CFL check the resistance or continuity of the filament of florescent tube, if any one side is open the tube will not work and you have to replace it, if the resistance measures around 10 to 20 Ohm the filament is good and you have to search for the faulty components.

You need the front cap in which the florescent tube glued with same cement like material. To reuse that cap you have to remove florescent tube which is sometimes easily loosens from glue and come out. If it is not then you have to break the glass tube, be very careful while breaking it because it contains hazardous mercury gas, so break it in open space away from your body especially from eyes. Take care.


    
Four terminal florescent tube
Two terminal fluorescent tube

9W & 11W florescent ‘U’ shaped bent tubes with four pins normally used for emergency lamps will be suitable for your burnt out same wattage CFL’s even higher wattage CFL’s will glow these wattage tubes. But these type of bent tubes cost (Rs. 80/-) bit more compared to straight tubes (Rs.45/-).












With the same wattage there is one more type of same bent tube with two pins are available which have inbuilt starter which is used for the old type of conventional tube light circuit.
Two terminal tube with removed starter
Terminals Extended and fixed with cap 
If you With the same wattage there is one more type of same bent tube with two pins are available which have inbuilt starter which is used for the old type of conventional tube light circuit. already have such a type of tube you have to open the bottom end cap and remove the starter connected in series with leads having some length. In this way you can have four leads out as shown in fig. If you have 20W CFL then you can connect 18W or 20W straight 2ft tube light worth Rs. 45/- which is cheaper than small wattage U bent tubes. For 40W 4ft. regular use tube light set remove the conventional type ballast and starter and use 40W or higher watt CFL ballast.

Final connected terminals to ballast



Final connection








Connect the four florescent tubes leads with electronic ballast as shown in fig. It should be such that the capacitor must be in series with two filaments. Normally indicated with numbers (1) (2) & (3) (4) in electronic ballast. For straight tube light use end holders for connection and use nylon transparent fishing wire for holding weight of tube with angle holder fixed on wall as shown in fig. [3] For  neat look you can use 2ft. tube light frame.

Final 20W Light
Final 11W & 18W CFLs


Case 2:
Some times the fluorescent filament may remain good and some of the electronic components may be faulty, most of the time they blown off because of the high voltage induced in the circuit. Some of the frequently blown out components which I have found in the faulty CFL’s are as below. If you have thorough knowledge of electronic ballast circuit you may understand it better.

 For more knowledge follow this link,

http://www.pavouk.org/hw/lamp/en_index.html 

 There are mainly two type of circuits,

a)    Diac used for initial start up.

b)    Capacitor used for initial start up.

Faults may be like

1)    Diac may shorted    

2)    Capacitor in series in b/w two leads of florescent tube may shorted which is heavily loaded during start up          

3)    Main transistors may shorted        

4)    Bridge rectifier diodes may shorted             

5)    Resistor connected between emitter of transistor and ground may burnt out

My intention of this post is to minimize the electronic disposal on earth because it is house hold item and people normally throws it in the dust bin and save your money as well as our nation’s resource.



Glowing Modified 18W CFL
Glowing Modified 11W CFL