The document discusses RF light sources, which convert electrical power into visible radiation without electrodes, differing from conventional gas discharge lamps. It outlines various types of RF discharges, commercial RF light sources, their advantages such as low maintenance and high efficiency, as well as disadvantages like higher costs and electromagnetic interference challenges. The conclusion emphasizes the potential for increased durability and efficiency in lighting applications due to the absence of 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 .