| 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 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 |
| 0.45φ lead 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). |
| |
  |
| |
