HWCC468

1/2 WATT CARBON COMPOSITION Features: Low inductance / High Frequency Performance High Surge / High Pulse Capability Rugged Construction Carbon Composition resistors are commonly used in high frequency, fusing, or pulse applications including: Snubbers Lightening Surge Protection Circuits Grounding Resistors RFI Suppression Value in Ohms 10 12 15 18 22 27 33 39 47 56 68 82 100 120 NTE Stock Number HWCC010 HWCC012 HWCC015 HWCC018 HWCC022 HWCC027 HWCC033 HWCC039 HWCC047 HWCC056 HWCC068 HWCC082 HWCC110 HWCC112 NTE Stock Number Value in Ohms 150 180 220 270 330 390 470 560 680 820 1K 1.2K 1.5K 1.8K HWCC115 HWCC118 HWCC122 HWCC127 HWCC133 HWCC139 HWCC147 HWCC156 HWCC168 HWCC182 HWCC210 HWCC212 HWCC215 HWCC218 NTE Stock Number Value in Ohms 2.2K 2.7K 3.3K 3.9K 4.7K 5.6K 6.8K 8.2K 10K 12K 15K 18K 22K 27K Value in Ohms HWCC222 HWCC227 HWCC233 HWCC239 HWCC247 HWCC256 HWCC268 HWCC282 HWCC310 HWCC312 HWCC315 HWCC318 HWCC322 HWCC327 33K 39K 47K 56K 68K 82K 100K 120K 150K 180K 220K 270K 330K 390K NTE Stock Number NTE Stock Number Value in Ohms HWCC333 HWCC339 HWCC347 HWCC356 HWCC368 HWCC382 HWCC410 HWCC412 HWCC415 HWCC418 HWCC422 HWCC427 HWCC433 HWCC439 470K 560K 680K 820K 1M HWCC447 HWCC456 HWCC468 HWCC482 HWCC510 SPECIFICATIONS Electrical Characteristics @ 70 C NTE Number Resistance Range (Ohms) Tolerance (%) Voltage (Volts) Operating Temperature (Topr) HWCC010 thru HWCC382 HWCC410 thru HWCC510 10 to 82K 100K to 1M 10 10 350 350 −55 to +150 C −55 to +150 C Temperature Coefficient (PPM/ C) 0.15% 0.15% Mechanical* (Typical, inches/mm) NTE Number Body Length (L) Body Diameter (D) HWCC010 thru HWCC510 0.375 (9.53) 0.140 (3.56) * These dimensions are for reference only, please consult the factory for actual size. Lead Diameter (d) Lead Length (LL) 0.028 (0.71) 1.000 (25.4) D d LL L GENERAL INFORMATION Pros and Cons of Carbon Composition Resistors Carbon Composition resistors offer excellent surge and high−frequency performance due to the bulk nature of the resistance element. Unlike wirewound and film resistors, there are no windings of resistance wire, nor any film depositions to open under overload pulses. Since the resistance element is a hot− molded solid core comprised of resin and a carbon slug, without helical turns of resistance wire or film, the inductance is extremely low, essentially the same as a straight piece of wire. The trade−off for the excellent surge and high−frequency capability is a rather unstable environmental performance, particularly in humid environments, a condition well known by most circuit designers. Carbon composition resistors therefore should not be utilized in precision applications, which are generally better suited by other resistor families such as NTE’s standard Metal Film types. There is no single resistor family, however, that offers the unique specialty performance levels of the composition construction, but depending on circuit requirements, other models will often provide a suitable replacement. 16 NTE Electronics, Inc. Voice (973) 748−5089 FAX (973) 748−6224 http://www.nteinc.com 1/2 WATT CARBON COMPOSITION GENERAL INFORMATION (Cont’d) Moisture / Humidity Considerations Carbon Composition resistors are not as stable as other types of resistors, especially in higher humidity conditions and therefore not suitable for precision applications. For example, carbon comps may shift up to 10% during endurance testing. Most general purpose chip resistors have a maximum shift under the same conditions of less than 3%. Carbon comps are also highly susceptible to moisture penetration. Damp heat testing may cause carbon comps to shift up to 10%. For that reason, carbon comps are recommended to be used soon after purchase, especially once the bag is opened. However, even in a sealed poly−bag, carbon comps may shift up to 5% in a year. Resistance changes due to humidity/ moisture can be positive or negative (mostly positive) and is usually reversible by conditioning the resistors at 100 −105 C or by dry storage. Before being considered failures, out−of−tolerance resistors should be conditioned in a dry oven at a temperature of 100 C +5 C for 96 4 hours prior to conducting resistance measurements, although some customers have had satisfactory results by baking 12−24 hrs at 110 −120 C. Regardless of the amount of baking, some units may not return to the original value. Typical levels of shift due to the absorption of moisture is generally less than 10% after 10 days of cycled humidity at 80−100% RH levels. Low and medium− value composition resistors typically exhibit less change due to humidity than high−value resistors. Parts should be stored in low humidity conditions (45% RH max). Conditioned (dry) resistors are the most sensitive to humidity. In operation, moisture absorption is minimized by operating the resistors with as little as 1/8th rated wattage load (the self−heating effect causes parts to dehumidify). NTE Electronics, Inc. Voice (973) 748−5089 FAX (973) 748−6224 http://www.nteinc.com 17