5w Sqz Cement Resistor For Communication

ELETRICAL CHARACTERISTICS:

G. TESTING CONDITION: All measurements are taken under the standard testing condition at the ambient temperature of 25℃ ±2℃ and the relative humidity of 65% ±5%.

H. TESTING METHOD AND REQUIREMENTS: H.1 Resistance Value  It is measured by bridge-method with the applied voltage not exceeding 1/10 of the rated voltage for 5  seconds; the allowable tolerance of all the resistance values within the E24 series is indicated as  follows:  Tolerance Code J  Actual Tolerance ±5%

H.2 Temperature Coefficient:  Take down the resistance value at the ambient temperature (25℃) and the value after the test taken at the temperature of higher than 100℃ for about 30-40 minutes, the readings will be used  with the following formula to get the T.C. of ±350 PPM/℃.  T.C(PPM/℃) =(R - R0) / R0 × 1/(T - T0) where T0 : ambient temperature of 25℃ T : test temperature of about 125℃ R0: resistance value at ambient temperature of 25℃ R : resistance value at test temperature of 125℃

H.3 Short Time Over Load: To apply an additional 1.5 times of the rated voltage power on the tested resistor, if the voltage surpasses the maximum working voltage, follow the maximum working voltage. After 5  seconds, remove the voltage and place the resistors to the normal condition for 30 minutes, take the reading of the resistance values between pre-and-post test, by using the following formula, the resistance change rate shall be within the range of ±(2.5%R+0.05Ω).  Resistance change rate %= (R-R0)/R0 × 100  where R0=Resistance value before test  R =Resistance value after test

H.4 Temperature Cycle: Following the following 4-step temperature cycles for 5 times, there should have no mechanical damage on the resistor body, the resistance value change rate between pre-and-post test shall be within the range of ± (2.0%R+0.05Ω)

H.5 Moisture-proof Load Life: The resistors are put into a constant temperature/ humidity oven where the temperature is 40±2℃ and the relative humidity is 90~95% with the related voltage (not exceeding the maximum working voltage) for 90 minutes and then draw the resistors back to the normal room temperature for 30 minutes-take this as a test cycle. Repeat this test cycle for 500 or  1,000 hours. Leave the tested pieces back to a room temperature for about 60 minutes after the test cycle, take the readings of the resistance value change between pre-and post-test, the change rate is about ±(5.0%R±0.05Ω)

H.6 Solder Heat Resistance: 95% of the circumference of the two lead wire terminals (about 4.0mm±0.8mm off the resistor body )  is to be dipped into a solder pot with melted solder of 350℃±5℃ for 10 ±1 seconds.Thereafter, put  the resistors back to normal temperature for 3 hours. Take the reading of the resistance value change rate between pre-and-post test which is about ± (2.0%R+0.05Ω)

H.7 Load Life: Leave the resistors on a test stand and put all the samples inside a constant temperature oven of  70℃± 2℃, be sure there is no temperature interference on the resistors in the oven, apply D.C.  rated voltage (not exceeding the maximum working voltage) for 90 minutes, off power 30  minutes-take this as a test cycle. Repeat this test cycle for 1,000 hours and then leave the tested pieces back to a normal room temperature for an hour for cooling.  Take the reading of the resistance value change rate between pre-and-post test which shall be within the range of ± (5%R+0.15Ω)

H.8 Fusing characteristics and definition:

H.8.1. The power rating is 1W, the resistance value is 68Ω, apply 25 times of the rated power on the resistor, the sample piece will be fused within20~ 60 seconds. The fusing voltage calculation is as follows:

H.8.2 Fusing definition: The value of the tested piece becomes magnitude or 100 times or above of the resistance value.

H.8.3 The fusing characteristics will differ from the standard conditions on any values under 1Ω. Quality representative samples will be submitted for approval prior to production.