| 1. Scope of the coverage : |
| This specification is pertinent to the application
of fixed carbon film resistors (designated as RD) |
| 2 .Temperature range of the application : |
| -55℃ ∼ +155℃ |
| 3. Type : |
| Two types of fixed carbon film resistors are available,
one is normal size and the other one is small |
| size. |
| Except the color of S1/2W which is pinkish red epoxy
resin, the rest of the epoxy resin color is |
| brownish yellow. |
| 4.Marking and illustration : |
| The marking method for the fixed carbon film resistor
is color code which is shown in Fig.1 |
 |
| Illustration of color codes : |
|
|
1-st Band
(Sig. digit)
|
2-nd Band
(Sig. digit)
|
3-rd Band
(Multiplier)
|
4-th Band
(Tolerance)
|
|
Black
|
0
|
0
|
1
|
.
|
|
Brown
|
1
|
1
|
10
|
±1%
|
|
Red
|
2
|
2
|
100
|
±1%
|
|
Orange
|
3
|
3
|
1000
|
.
|
|
Yellow
|
4
|
4
|
10000
|
.
|
|
Green
|
5
|
5
|
100000
|
±0.5%
|
|
Blue
|
6
|
6
|
1000000
|
±0.25%
|
|
Purple
|
7
|
7
|
10000000
|
±0.1%
|
|
Gray
|
8
|
8
|
.
|
±0.05%
|
|
White
|
9
|
9
|
.
|
.
|
|
Gold
|
.
|
.
|
0.1
|
±5%
|
|
Silver
|
.
|
.
|
0.01
|
±10%
|
|
| |
| 5.Dimension, voltage, resistance range : listed
in the following table |
|
Type
|
Rated
Power
W
|
Resistance
Range Ω
|
Highest
working
V
|
Highest
Overload
V
|
 2 |
|
J ( ±5%)
|
L
|
Dψ
|
ι
|
dψ
|
|
Normal
|
1/8W
|
2.2∼1M
|
250
|
400
|
3.5±0.5
|
1.7±0.3
|
27±3
|
0.45±0.05
|
|
Normal
|
1/6W
|
2.2∼1M
|
250
|
400
|
3.5±0.5
|
1.7±0.3
|
27±3
|
0.45±0.05
|
|
Small
|
S1/4W
|
2.2∼1M
|
250
|
400
|
3.5±0.5
|
1.7±0.3
|
27±3
|
0.45±0.05
|
|
Normal
|
1/4W
|
2.2∼5.1M
|
300
|
600
|
6.0±0.5
|
2.3±0.3
|
27±3
|
0.52±0.05
|
|
Small
|
S1/2W
|
2.2∼5.1M
|
300
|
600
|
6.0±0.5
|
2.3±0.3
|
27±3
|
0.52±0.05
|
|
Normal
|
1/2W
|
2.2∼5.1M
|
300
|
700
|
9.0±1.0
|
3.2±0.5
|
27±3
|
0.56±0.05
|
|
| |
| 6.Coating : |
 |
| 6.1 The body of the resistor is covered by nonflammable
silicon resin. |
| 6.2 The maximum length of the lead wire covered by
the resin is 0.5mm. |
| 6.3 The maximum area of the end cap which is not
covered by the resin is half of the diameter of the
|
| 6.3 cap. |
| 6.4 The status of coating condition described by
6.2 and 6.3 are acceptable. |
| |
| 7.Characteristics of electrical performance : |
| 7.1 Rated power |
| The rated power indicates the maximum power the resistor
can endure continuously when the |
| ambient temperature is equal to or lower than 70℃.
When the ambient temperature is higher than |
| 70℃, the rated power of the resistor is determined
by the derating curve described in the following |
| figure. |
 |
| 7.2 Rated voltage |
| The rated voltage of a resistor is either a continuous
DC voltage or an AC rms voltage which can be |
| calculated by the following formula. If the calculated
rated voltage is higher than the highest |
| working voltage then the highest working voltage
should be used as the rated voltage. |
 P:
Rated power(W), R: Nominal resistance(Ω), E: Rated voltage(V) |
| |
| 7.3 Insulation resistance (Ref. JIS C5202
5.6) |
| Equipment : Insulation resistance tester |
| The body of the resistor is wrapped around by the
aluminum foil without extending beyond the |
| resistor body. Clap one electrode on the aluminum
foil and the other electrode on the lead wire. |
| Apply 100V from the tester for 1 min. and the measured
resistance value should be larger than |
| 1,000MW. |
| |
| 7.4 Dielectric strength (Ref. JIS C5202 5.7) |
| Equipment: Dielectric strength tester |
| The body of the resistor is wrapped around by the
aluminum foil without extending beyond the |
| resistor body. Clap one electrode on the aluminum
foil and the other electrode on the lead wire. |
| Apply following voltage from the tester to the resistor
for 1 min.. No flash-over, burning or breakdown |
| should be observed. |
|
Rated power (W)
|
1/8W
|
1/6W
|
S1/4W
|
1/4W
|
S1/2W
|
1/2W
|
|
Voltage (V)
|
300V
|
300V
|
300V
|
500V
|
500V
|
700V
|
|
| |
| 7.5 Short time overload (SOL) (Ref. JIS C5202 5.5) |
| Equipment: S.O.L. tester. |
| Apply 2.5 times of rated voltage to the resistors
for 5 seconds. If the applied voltage is larger than
the |
| voltage listed in the following table, then the voltage
in the table should be used instead. After the |
| test, the sample should be stabilized at room temperature
for 30 min. before the resistance is |
| measured. The change of the resistance before and
after the test should be ±(1%+0.05Ω)。 |
|
Rated power
|
1/8W
|
1/6W
|
S1/4W
|
1/4W
|
S1/2W
|
1/2W
|
|
Highest voltage
|
400V
|
400V
|
400V
|
600V
|
600V
|
700V
|
|
| |
| 7.6 Intermittent overload (Applicable for nominal
resistance larger than 100Ω) (Ref. JIS C5202 5.8) |
| Equipment: Intermittent tester |
| Put the resistor to a test fixture in
a horizontal position, apply Y times of rated voltage
for 1 sec. ON |
and 25 sec. OFF for 
times. After the test, take the sample out and stabilize
at room |
| temperature for 30 min. then measure its resistance.
The acceptable change of resistance before |
| and after the test is ±(1%+0.05Ω). The applied voltage
should not exceed the value listed in the |
| following table. |
|
Rated power
|
1/8W
|
1/6W
|
S1/4W
|
1/4W
|
S1/2W
|
1/2W
|
|
Highest V
|
500V
|
500V
|
500V
|
750V
|
750V
|
1000V
|
|
Times: Y
|
3
|
3
|
3
|
4
|
4
|
4
|
|
| |
| 8.Environmental tests |
| 8.1 Load life test (Endurance with rated
load) (Ref. JIS C5202 7.10) |
| Equipment: High temperature chamber and DC power
supply |
| The resistors are put in a fixture where no interference
will be allowed. Put the fixture in a 70±3℃ |
chamber and apply rated voltage with a
cycle of 90 min. ON and 30 min. OFF for 
hours. After |
| 240, 480, 720 and 1,000 hours, the resistors
are taken out and stabilize at room temperature for
30 |
| min. and then the resistance is measured. Upon each
step of resistance measurement, the change |
| of the resistance should not exceed ±(5%+0.1Ω) and
the appearance should show no remarkable |
| abnormality and legibility of marking. |
| |
| 8.2 Endurance under damp heat and load (Ref. JIS
C5202 7.9) |
| Equipment: Constant temperature and humidity chamber,
DC power supply |
| The resistors are put in a fixture where no interference
will be allowed. Put the fixture in a 40±2℃ |
| chamber with RH=90∼95% and apply rated voltage with
a cycle of 90 min. ON and 30 min. OFF for |
|
hours. Water drops should avoid dripping on the resistors.
After 240 and 1,000 hours, the |
| resistors are taken out and stabilize at room temperature
for 1 hour and then the resistance is |
| measured. Upon each step of measurement,
the change of the resistance should not exceed |
| ±(5%+0.1Ω) and the appearance should show
no remarkable abnormality and legibility of marking. |
| |
| 8.3 Temperature coefficient (TCR) (Ref. JIS C5202
5.2) |
| Equipment: High temperature chamber |
| Measure the resistance at room temperature. Put the
resistor in a chamber with the temperature of |
| RT+100℃ for 30 - 45 min. to stabilize. Measure the
resistance again. Compare the resistance at |
| these two temperatures with the following equation.
The acceptable change of resistance is listed |
| in foloowing table. |
 |
| R = Resistance at T T = RT + 100℃ Ro = Resistance
at To To =room temperature |
|
Rated power
|
TCR (ppm)
|
|
+350∼-450
|
0∼-700
|
0∼-1000
|
0∼-1500
|
|
1/8W、1/6W
|
2.2∼47K
|
51K∼100K
|
110K∼330K
|
360K∼1M
|
|
S1/4W
|
2.2∼47K
|
51K∼100K
|
110K∼330K
|
360K∼1M
|
|
1/4W
|
2.2∼100K
|
110K∼330K
|
360K∼1M
|
1.1M∼5.1M
|
|
S1/2W
|
2.2∼91K
|
100K∼1.5M
|
1.6M∼5.1M
|
.
|
|
1/2W
|
2.2∼100K
|
110K∼1M
|
1.1M∼2.2M
|
2.4M∼5.1M
|
|
| |
| 8.4 Temperature cycling (Ref. JIS C5202 7.4) |
| Equipment: High temperature chamber, low temperature
chamber |
| Measure the resistance before the test. Put the resistor
to -55℃ chamber for 30 min. then take it |
| out at room temperature for 2 to 3 min.. Put the
resistor to +85℃ chamber for 30 min. then take it |
| out at room temperature for 2 to 3 min. This completes
a cycle. Repeat the cycle 5 times. Put |
| resistors at room temperature for 90 min. and then
measure the resistance. Compare the |
| resistance before and after test. The acceptable
change of resistance is ±(1%+0.05Ω). The |
| appearance should show no remarkable abnormality
and legibility of marking. |
| |
| 9.Mechanical performance |
| 9.1 Resistance to soldering heat (Ref. JIS C5202
6.4) |
| Equipment: Solder bath |
| Measure the resistance before the test. Immerse part
of the lead wire which is 6±0.8mm away from |
| the body to the flux for 5 - 10 sec. Take the resistor
out and immerse resistors in the solder bath of |
| 350±10℃ for 3.5±0.5 sec.. Stabilize at room temperature
for 1 hour and then measure the |
| resistance value. Compare the resistance values before
and after the test, The acceptable change |
| is ±(1%+0.05Ω). |
| |
| 9.2 Solderability (Ref. JIS C5202 6.5) |
| Equipment: Solder bath |
| Immerse part of the lead wire which is 3±0.8mm away
from the body to the flux for 5 - 10 sec. Take |
| the resistor out and immerse resistors
in the solder bath of 245±5℃ for 3.5±0.5 sec.. Take
the |
| resistor out and inspect the lead wire
visually. The acceptable level is the coverage of the
new |
| solder to be 95%. The composition of the solder bath
is 99.7% tin and 0.3% Cu. |
| |
| 9.3 Robustness of terminals (Ref. JIS C5202 6.1) |
| 9.3.1 Tensile strength of termination |
| Equipment: Weight gauge |
| Fixed the resistor and apply axially along the lead
wire of 1.0kg (0.45φ,0.52φ, 0.60φlead wire) for 30 |
| sec.. The lead wire should not break or detached
from the resistor and the change of the resistance |
| should be less than ±(1%+0.05Ω). |
| |
| 9.3.2 Torsional strength |
| Equipment: Torsion tester |
| Bend the terminal 6.4mm away from the body according
to Fig-a to 90 degree with a curvature of |
| 0.75mm∼0.80mm. The lead wire should be clamped at
a point of 1.2mm away from the bending |
| point by a fixture which can rotate 360 degree according
to Fig-b. Rotate the resistor 360 degree |
| clockwise and counter clockwise for 1 cycle. The
rotation speed is 360 degree per 5 sec. Perform |
| 0.45φlead wire 1 cycle and 0.52φ, 0.60φ 1.5 cycles.
The terminal should not break down or |
| detached from the body. The acceptable change of
resistance is ±(1%+0.05Ω). |
| |
|
| |
