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2381 66. 93.../PTCLL..P....E
Vishay BCcomponents
DESCRIPTION
The conventional fluorescent strip lamp is rapidly being
superseded by a more compact fluorescent lamp in which
the old troublesome starter is replaced by an electronic
ballast circuit which pre-heats the cathode to make ignition
easy.
Positive Temperature Coefficient (PTC) thermistors for
overload protection have proved to be the ideal electronic
ballast component for companies worldwide.
When the rectified mains is first applied, the PTC thermistor
is cold, so its resistance is low. The lamp voltage will be
below the necessary ignition value, so the current will flow
through the cathodes, heating them to their emission
temperature. At the same time, the PTC thermistor will heat
up to its switch temperature, whereupon its resistance will
rise rapidly, allowing the lamp voltage to reach its ignition
value and light the lamp.
Notes
1. Ignition time of the lamp approximately equals the tripping time.
2. Specific for PLC-E lamp electronic starter.
3. Specific for HF-TL ballast.
ELECTRICAL DATA AND ORDERING INFORMATION
230 V a.c. mains)
MIN.
rectified mains
(310 V d.c. for
500
185
225
75
75
R
(Ω)
25
MAX.
750
300
125
375
125
C
C
Typical electronic ballast circuit.
PTC Thermistors, Time Delay For Lighting
TEMPERATURE
cathode cathode
PTC thermistor
fluorescent
SWITCH
≈ 110
≈ 120
≈ 105
≈ 105
lamp
θ
≈ 80
(°C)
C
For technical questions, contact: nlr.europe@vishay.com
switch
switch
FET
FET
L
(PEAK VALUE)
MAXIMUM
VOLTAGE
1000
700
700
700
900
(V)
36 kHz
supply
lamp
TRIP TIME at 25 °C
0.75
0.85
0.4
0.5
0.7
(s)
Tt
FEATURES
•
• Accurate resistance for ease of circuit design
• Small size and durable
• Available bulk-packed or taped-on-reel
• Long life: more than 20000 starts for a 20 W lamp
• Component in accordance to RoHS 2002/95/EC and
APPLICATIONS
•
•
Once the lamp is lit, the cathodes are fed by a high-frequency
(36 kHz) lamp supply, to avoid flicker, via two power FET
switches. The PTC thermistor plays no further part until the
lamp is switched off, whereupon it is ready to resume its
smooth-starting function.
We supply a range of overload PTC thermistors for this
application offering a wide choice of voltage and switch
temperatures.
MOUNTING
The leads are suitable for soldering in any position. The
lacquer may cover the leads up to 1.0 mm from the seating
plane.
PACKAGING
All tape and reel specifications are in accordance with “IEC
60286-3”.
TYPICAL
Reliable starting, time and time again
WEEE 2002/96/EC
Domestic electronics
Industrial electronics
(mA)
1)
at It
200
300
300
300
500
2381 660 93049
2381 660 93055
2381 660 93066
2381 661 93102
2381 661 93114
12 NC
CATALOG NUMBER
2)
2)
2)
3)
3)
Document Number: 29071
PTCLL07P421WTE
PTCLL05P131TBE
PTCLL05P211TTE
PTCLL05P251TTE
PTCLL07P261VTE
Revision: 06-Sep-06
SAP CODING
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