The fundamental difference between RF lamps and conventional lamps is that RF lamps operate without electrodes

1. A Technical Seminar
On
RF light sources
Rakesh Mandiya
Rakesh.yadav1211@gmail.com
Delhi Technological University

2. INTRODUCTION
RF light sources follow the same principles of
converting electrical power into visible radiation
as conventional gas discharge lamps.
The fundamental difference between RF lamps
and conventional lamps is that RF lamps operate
without electrodes.

3. RF LIGHTING
RF lamps, appeared about 100years ago, a half
century before the basic principles lighting
technology based on gas discharge had been
developed.

4. DISCHARGE TYPES
Capacitive RF Discharge
Inductive RF Discharge
Wave –Sustained Discharges

5. Capacitive RF Discharge
 The voltage applied to the
lamp is mainly dropped in
the sheaths.

6. Inductive RF Discharge
power transfer efficiency
 = Pp/(Pp+Pc)
operate over a wide range of
gas pressure and frequency
for which L.

7. CHOICE OF FREQUENCY AND
DISCHARGE TYPE
the frequency rage between 2.2 – 3.0 MHz
(2.65MHz is standard) has reduced
restrictions on EMI.
For frequencies at a few tens of kilohertz.,
generator efficiency is rather high.

8. COMMERCIAL RF LIGHT SOURCES
Microwave- Powered Sulphur Lamps
Spherical External- Coil Induction Lamp
Re-entrant Cavity Induction Lamp
Self- Ballasted Re-entrant Cavity Lamp
Low- Frequency Extended-coil Induction Lamp

9. Microwave- Powered Sulphur Lamps
 life rating of 15,000
hr.
 low infrared and
ultraviolet emission
 good colour
stability

10. SPHERICAL EXTERNAL- COIL
INDUCTION LAMP
 induction coil
wrapped around the
lamp
 screen cage
surrounds the lamp
 operate at 27 W
 efficiency is 37
lm/W

11. RE-ENTRANT CAVITY INDUCTION
LAMP
 operating at 2.65MHz
 available in three
wattages –55W,
85W,and 165W
 shaped standard
incandescent lamps
 100,000-hr average
rated life

12. SELF- BALLASTED RE-ENTRANT
CAVITY LAMP
lamp power is 23 W at
48 lm/W
operating at 2.65 MHz
lamp life is rated up to
15,000 hours

13. LOW- FREQUENCY EXTENTED-COIL
INDUCTION LAMP
consist of a 5.4 cm diameter
Pyrex glass tube
operating frequency of 250 kHz
minimizes the problems
associated with EMI
ballast design is much simpler
than an RF system working at
2.65MHz

14. ADVANTAGES
Absence of electrodes.
Maintenance is low.
Gas pressure is optimized for maximal
efficiency in RF lamps.
It have instant and harmless starting.
Efficiency is high.

15. DISADVATAGES
Cost is higher than fluorescent lamps.
With increasing frequency, efficiency will
decrease,
It is woks efficiently for some particular
frequencies, if frequency changes there are
problems with electromagnetic interference
(EMI).

16. FUTURE SCOPE
Induction lighting is an economical choice for
many plants.
Induction lamps are suitable for a range of
installations, including general lighting within
a plant, as well as out door areas.

17. CONCLUSION
The elimination of electrodes opens up great
opportunity for increased durability, light output
and efficiency.
It removes many of the lamp-shape restrictions of
conventional electrode discharge lamps .