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Technical Specifications |
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For SR
Surge Resistors with Surge Energy Rating
660J - 1.8 kJ: |
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RESISTOR
TYPE |
DIM.
CODE |
OVERALL
DIMENSIONS |
VOL. |
MAX.
J |
MAX.
W |
T.T.C. |
WT. |
A/L |
RESISTANCE RANGE |
|
Do
Max |
Lo
Max |
Lp
Pitch |
(v)
|
@25˚C
|
@25˚C
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(t)
|
MIN |
MAX |
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UNITS |
|
(mm) |
(mm) |
(mm) |
(cm3) |
(J) |
(W) |
(s) |
(g) |
(cm) |
(Ohms) |
(Ohms) |
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SR 0775 |
1911 |
21 |
15 |
11 - 12 |
3.1 |
775 |
3.00 |
260 |
9.0 |
2.6 |
3R9 |
1K8 |
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SR 1000 |
1914 |
21 |
18 |
14 - 15 |
4.0 |
1000 |
3.50 |
285 |
10.5 |
2.0 |
5R6 |
2K7 |
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SR 1200 |
1917 |
21 |
21 |
17 - 18 |
4.8 |
1200 |
3.75 |
320 |
13.0 |
1.7 |
6R8 |
3K3 |
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SR 1425 |
1920 |
21 |
24 |
20 - 21 |
5.7 |
1425 |
4.25 |
335 |
15.0 |
1.4 |
8R2 |
3K9 |
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SR 1775 |
1925 |
21 |
29 |
25 - 26 |
7.1 |
1775 |
5.00 |
355 |
18.0 |
1.1 |
10R0 |
4K7 |
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NOTES |
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Vol (v) = Volume
of Active Material (cm3) |
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T. T. C. = Thermal Time Constant
(t)
(Seconds) |
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Maximum
Working Voltages
(V
working) |
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The Maximum Working Voltage levels can
be derived from the appropriate formulae illustrated in the tables
below. Examples are shown at the foot of this page.
Waveforms are defined in the usual manner: 1.2 / 50 µs indicates
a rise time to peak value in 1.2 µs and an exponential decay to half
amplitude in a total time of 50 µs. |
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SR 0775 |
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IMPULSE / WAVESHAPE |
MAX. WORKING VOLTAGE (kV) |
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(50 Hz rms) |
1.0 x ( 2.6R / t )
0.3 |
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(1.2 / 50 µs) |
0.79R x ( -1 + √ (
1 + 23 / R ) ) |
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(10 / 1000 µs) |
0.0393R x ( -1 + √ ( 1 +
462 / R ) ) |
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(500 / 5000 µs) |
0.0079R x ( -1 + √ ( 1 +
2308 / R ) ) |
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SR 1000 |
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IMPULSE / WAVESHAPE |
MAX. WORKING VOLTAGE (kV) |
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(50 Hz rms) |
1.3 x ( 2.0R / t )
0.3 |
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(1.2 / 50 µs) |
0.79R x ( -1 + √ ( 1 +
29 / R ) ) |
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(10 / 1000 µs) |
0.0393R x ( -1 + √ ( 1 +
588 / R ) ) |
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(500 / 5000 µs) |
0.0079R x ( -1 + √ ( 1 +
2938 / R ) ) |
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SR 1200 |
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IMPULSE / WAVESHAPE |
MAX. WORKING VOLTAGE (kV) |
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(50 Hz rms) |
1.6 x ( 1.7R / t )
0.3 |
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(1.2 / 50 µs) |
0.79R x ( -1 + √ ( 1 +
36 / R ) ) |
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(10 / 1000 µs) |
0.0393R x ( -1 + √ ( 1 +
714 / R ) ) |
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(500 / 5000 µs) |
0.0079R x ( -1 + √ ( 1 +
3568 / R ) ) |
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SR 1425 |
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IMPULSE / WAVESHAPE |
MAX. WORKING VOLTAGE (kV) |
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(50 Hz rms) |
1.9 x ( 1.4R / t )
0.3 |
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(1.2 / 50 µs) |
0.79R x ( -1 + √ ( 1 +
42 / R ) ) |
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(10 / 1000 µs) |
0.0393R x ( -1 + √ ( 1 +
839 / R ) ) |
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(500 / 5000 µs) |
0.0079R x ( -1 + √ ( 1 +
4197 / R ) ) |
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SR 1775 |
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IMPULSE / WAVESHAPE |
MAX. WORKING VOLTAGE (kV) |
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(50 Hz rms) |
2.4 x ( 1.1R / t )
0.3 |
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(1.2 / 50 µs) |
0.79R x ( -1 + √ ( 1 +
52 / R ) ) |
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(10 / 1000 µs) |
0.0393R x ( -1 + √ ( 1 +
1049 / R ) ) |
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(500 / 5000 µs) |
0.0079R x ( -1 + √ ( 1 +
5246 / R ) ) |
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Worked example (50 Hz rms) :
Consider an SR
1200 Resistor with a Resistance Value of 100R0.
What is the
maximum 50 Hz rms Working Voltage (kV) sustainable for an insertion time
of 100 ms?
V working = 1.6
x (1.7R / t) 0.3 =
1.88 kV
(Note: R =
Resistance Value in Ohms and t = 50 Hz Insertion time in ms) |
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Worked example
(10 / 1000 µs) :
Consider an SR 1200 Resistor with a Resistance Value of 100R0.
What is the maximum Working Voltage (kV) for a
10 / 1000
µs waveform?
V working =
0.0393R x (-1 + √(1 + 714 / R)) = 7.28 kV |
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