RESISTOR GLOSSARY
Rated Power
The maximum value of power, which can be continuously loaded to
a resistor at a rated ambient temperature. Please confirm beforehand
that there is such a case in a network that rated power per package
as well as per element is specified.
Rated Voltage
The maximum value of D.C. voltage or A.C. voltage (commercial frequency
effective value) capable of being applied continuously to resistors
at the rated ambient temperature. Rated voltage shall be calculated
from the following formula. However, it shall not exceed the maximum
working voltage. Rated Voltage (V) = √Rated Power (W) × Nominal Resistance Value(Ω)
Critical Resistance Value
The maximum nominal resistance value at which the rated power can
be loaded without exceeding the maximum working voltage. The rated
voltage is equal to the maximum working voltage in the critical resistance value.
Maximum Working Voltage
The maximum value of D.C. voltage or A.C. voltage (commercial frequency
effective value) capable of being applied continuously to resistors
or element. However, the maximum value of the applicable
voltage is the rated voltage at the critical resistance value or lower.
Maximum Overload Voltage
Specifications given herein may be changed at any time without
prior notice. Please confirm technical specifications before you order
and/or use. The maximum value of voltage capable of being applied
to resistors for five seconds in the overload test. (JIS C 5201
1 4.13) Typically the applied voltage in the short time overload test
shall be 2.5 times larger than the rated voltage. However, it shall
not exceed the maximum overload voltage.
Dielectric Withstanding Voltage
A.C. voltage (commercial frequency effective value) that can be
applied to a designated spot between the electrode and the outer coating
for a minute in the dielectric withstanding voltage test. (JIS C 5201 1 4.7)
Rated Ambient Temperature
The maximum ambient temperature at which resistors are capable of
being used continuously with the prescribed rated load (power). The
rated ambient temperature refers to the temperature around the resistors
inside the equipment, not to the air temperature outside the equipment.
Derating Curve
The curve that expresses the relation between the ambient temperature
and the maximum value of continuously loadable power at its temperature,
which is generally expressed in percentage.
Temperature Coefficient of Resistance (T.C.R.)
The rate of change in resistance value per 1 °C in the prescribed
temperature within the range of resistors operating temperature shall
be expressed in the following formula: T.C.R. (ppm/°C) =(RRo)/Ro × 1/(TTo) × 10^{6}
R: Measured resistance(Ω) at T °C Ro: Measured resistance(Ω) at To °C T: Measured test temperature(°C) To: Measured base temperature(°C)
