Theatre Design & Technology - Summer 1982 - 25

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_____________ -,,_ :a~c~a~ce Starter

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1.1

1,200 W Short-Arcing
Halogen Metal-Vapor Lamp
with Holmium
,

Fluorescent Lamp.

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Fluorescent
Lamp

r---~=i;illi;~=====~
Filament Transformer

Ballast

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20

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10

400

500

600

700

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Spectral Distribution of Energy of a Short-Arcing Halogen
Metal-Vapor Lamp with Holmium

Mp
Phase
Conductor

Controlled
Phase

Central
Conductor

Schematic for Fluorescent Lamp
Electrode Heating Data Table:

0'6.----~"....._-....,...----_:___,_-"""'""2500=·:----,.-----,

01.5

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0'2

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yellow

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--

038
035

16

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>- 032

red

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026
0.26

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7000"

.

blue tCc . * * purple _'

Control Range 100%
to approximately 20%

o 2' '-::-::::26~26:-:0""30""0:-:J"'"2':':OJL""""'O.lJ""-;:0."'38'""0":':LO'""0":':'2""'0"",,""""'/.5:-:0"'"L/l""0:"::5"'"0':':05"'"2':':0.51-:-:-::"05""6"::'0""56"::'0:-::60'""0""'.62:-=0 f>t.

x

Type Lamp
L 20W/----;Sa
L 40W/
Sa
L 40W/
S
L65W/
Sa
L 40W/
Ds
L 42W/
Ds
Ds
L 65W/

Rated Value
of Filament
Voltage Ur
4.0 V
4.0 V
4.0 V
4.0 V
6.5 V
4.0 V
6.5 V

Maximum Permissable
Current Per
Electrode Lead-In IE
0.55 A
0.65 A
0.65A
1.00 A
0.65 A
0.80 A
1.00 A

S = Lamps with siliconized bulbs
Sa = Lamps with siliconization and exterior starter coating.
Ds = Lamps with glued-on starter foil.

*

Variations in Color Location with Output Control of Various
Types of Lamps

possible. Variations in color temperature are relatively slight
during output control. Greater variations can occur with the
use of the metals natrium, thallium, and indium.
Planckian Combined Curve: Color temperature of temperature radiators.
Judd's Coefficient: Range of approximated control of the
color temperature of various types of lamps from 100% to
approximately 20% output control.
Incandescent Lamp [GL in above chart): Color location along
Planckian Combined Curve. PL smaller, TK lower, x-value
rises, y-value nearly constant.
Sodium High-Pressure Lamp [NaH in above chart): Color of
emitted light yellow with a drop in output; x-value rises; yvalue nearly constant.
Mercury High-Pressure Lamp with Fluorescent Material
[HgH in above chart]: Almost no change in color location
under output control. A reduction in output can result in a
slight increase as well as a decrease in color temperature.
Halogen Metal-Vapor Lamp [Hgi in above chart): Wide variation in color location as a result of varying characteristics of
individual fill components. Little change in color temperature with a reduction in output, but emitted light becomes
increasingly green.
Fluorescent Lamp [HL in above chart]: Practically no change
in color location and color temperature.
Short-Arcing Halogen Metal-Vapor Lamp [HMI/RSI in above
chart): Color location near the illuminant (E): x = 0.33; y =
0.33; t = 5,600 K.
General: Standard Light: A = t = 2,856 K Standard Light:
C = t = 6,774 K Standard Light: D = t = 6,504 K

Finally, a few words with respect to the output control of
fluorescent lamps. Starter-free lamps are the type of lamps
which should be used for output control purposes. In the case
of standard fluorescent lamps reduced service life must be expected. Sixty-five watt lamps tend to flicker due to reignition
peaking. Lamp characteristics can be approved through the
use of a grounded metal grid over the lamp. Never use old and
new lamps in a system in order to insure uniform control characteristics. Twenty watt lamps can also be operated in a tandem network.
Note: Use particularly solid, steady mounts since shaky
mounts are one of the main causes of interference in
control systems due to the relatively electrode preheating current involved and damaging contact resistances which occur, for example, with the use of spring
terminal mounts with locking screws. Cheap dimmers
are only suitable for use with incandescent lamps.
Note the suitability of dimmers for fluorescent lamps
when buying. The filament voltage of the filament
transformer must be adapted to the respective type of
lamp involved. There are high-resistance and low-resistance electrodes.
Frequent causes of improper operation of controlled systems
include:
--excessively low supply voltage;
-unconnected or insufficient starters;
--excessive luminaire temperature;
-incorrect filament voltage;
-in the case of three-phase current systems an unfavorable
phase relation between the lamps and filament transformer
supply;
- a severe imbalance in phase cutoff equipment [flickering or
50 Hz flickering];
-poor contact within mounts subsequently causing unreliable preheating. D
Table of Contents for the Digital Edition of Theatre Design & Technology - Summer 1982
