Filter
Top Products
Mains voltage 90 % 100 % 110 %
Circuit Ind. Cap. Ind. Cap. Ind. Cap.
Z ballast (Ω) 440 440 400 400 360 360
Z capacitor (Ω) 800 800 800
Z result (Ω) 440 360 400 400 360 440
Therefore the behaviour of the inductive and capacitive branch of a
duo-circuit is different at mains voltage deviations and deviations of the
ambient temperature.This can be seen rather well in a duo-luminaire.
Series connection of lamps
Under certain conditions it is possible to operate two lamps in series
on a common ballast (see Fig. 117).A prerequisite for such operation
is that the sum of the operating voltages of the lamps is not higher
than approximately 60 per cent of the supply voltage.This means that
two lamps, each with an arc voltage of no more than 65 volt, can be
connected in series via a common ballast to the 220/240 V mains.This
restricts the maximum lamp length to 600 mm (2 ft), or the lamp
power to 18/20 W (26 or 38 mm diameter lamps only).
The series circuit can be compensated in the normal way by using a
parallel or series capacitor.
35
5
123
Fig. 116.Voltage/current characteristic
of an inductive ballast (example).
Fig. 117.Tandem circuit with two lamps
in series on a common ballast.
3.4 Power factor correction
180
180
180
180
180
180
180
180
180
180
180
160
140
120
100
80
60
40
20
100
200
300
400
500
600
700
800
900
1000
Z
1
= 165 = 360 Ω
Z
1
= 150 = 400 Ω
Z
1
= 135 = 440 Ω
____
0,458
____
0,375
____
0,307
1
2
3
V
ballast
(V)
I
ballast
(mA)
0
‘TL’1
‘TL’2
S
S