A resistor which has its resistance wire partly exposed to enable the amount of resistance in use to be occasionally adjusted. Possible adjustment is a sliding tap; or loosening of the tap screw, subsequent moving of the tap and retightening.
Carbon composition resistors consist of mixtures of granulated carbon and ceramic binder cylindrical resistive element with embedded wire lead-outs, or metal end caps, to which the lead-out wires are attached.
Resistors in which a carbon film is deposited on an insulating substrate and a spiral cut in it to create a long, narrow resistive path. Varying shapes, coupled with the resistivity of carbon, provide a variety of resistances.
Ceramic core resistors are generally wire-wound resistors constructed on a ceramic core and then conformally coated. This process enables the resistor to operate in very high temperatures, at high voltages, and in harsh industrial environments.
Resistors which use cermet construction in the manufacture of the resistance element. Advantages are high temperature use, wide resistance range, stability, and durability over wire-wound, metal film, carbon, etc. resistors.
Chip Resistors
(71 Companies)
Subminiature resistors (usually thick or thin film construction) which are packaged in a chip form and fastened directly to foil patterns.
A resistor placed in a current path to allow the current to be measured. The voltage across the sense resistor is proportional to the current that is being measured and an amplifier produces a voltage or current that drives the measurement.
Film Resistors
(54 Companies)
Metallized resistors are constructed where the resistance element is a thin film of metal (e.g. tungsten, nickel, etc.) deposited on a glass or ceramic substrate. A non-metallized film might be of carbon deposits.
Flame retardant resistors are specially constructed to reduce and prevent the spread of flames or fire–instead will generally emit smoke and red heat at excessive ambient temperatures or power dissipations.
A resistor which has two terminal pairs. Generally used in precision current sensing measurements to cancel out ground lead effects and contact resistance in the circuit.
General term for resistors which are designed to work into the RF and microwave frequency range. Construction of these components are usually of a thin film technology and packaged in chip or SMT design.
Defined as resistors whose value exceeds 22 megohms. Used in instrumentation, high voltage power supplies, X-ray devices, industrial, automotive and military applications, etc.
Defined as resistors which are rated at temperatures exceeding +125°C. Used in geophysical, industrial, automotive and military applications.
Defined as resistors which can exceed a voltage drop of 500 volts or more. Used in power supplies, X-ray devices, pulse applications, transient suppression, electrostatics, etc.
A resistor which has been encased in molded plastic or ceramic insulation. Generally provides high thermal conductivity to ensure cool operation and longer life.
Hybrid Networks
(38 Companies)
A hybrid network in this context refers to a microcircuit which contains semiconductor devices and passive resistive elements deposited upon a substrate to form an active network.
High power resistors which are designed to dissipate their heat into a mass of metal that is an integral part of the resistor. Also can be used with an external heat sink metal mounting base that absorbs the heat.
Ladder Networks
(36 Companies)
A grouping of multiple resistors in a series-shunt network used in circuit design for attenuators, filters, dividers, etc. Often network comprises "H-," "L-," "T-," or pi-networks connected in series. Available in SIP, DIP, chip, IC, etc. packages.
Resistors which exhibit a low change in resistance from their original specified value for a unit change in temperature.
A resistor in which the resistive element is an extremely thin layer of metal alloy, vacuum deposited on a substrate.
Resistance element is constructed with a special foil alloy several micrometers thick. Foil resistors have the best precision and stability and also low temperature coefficient of resistance.
A fixed resistor in which the resistance element is a thin film of metal deposited on the surface of a glass or ceramic substrate.
Type of resistor in which the material deposited on the substrate is tin oxide–which provides good stability.
Refers to resistors that experience a decrease in electrical resistance when their temperature is raised. The higher the coefficient, the greater a decrease in electrical resistance for a given temperature increase.
Non-Inductive resistors are constructed with little or no self-inductance or reactive effects at high frequencies. Usually these types of resistors are of film or foil construction.
Refers to resistors that experience an increase in electrical resistance when their temperature is raised. The higher the coefficient, the greater an increase in electrical resistance for a given temperature increase.
Power Resistors
(78 Companies)
Relative term applied to resistors designed to operate at high power dissipation levels–usually greater than a few watts. Resistors may require heat sink or external cooling for very high dissipations.
Resistors which are designed to offer a precise resistance value, usually under ±1% of nominal, but may be as precise as ±0.005% with very low temperature coefficient of resistance and high stability. Construction is commonly of a foil or film technology.
A fixed resistor where the resistance element is a thin layer of conductive material on an insulated form. Mechanical protection is then placed over this layer. Can also refer to a resistor whose characteristics depend on film rather than bulk properties.
Refers generically to a grouping of multiple resistors network. Network may comprise "H-," "L-," "T-," or pi-networks connected in series or individual selectable series/shunt resistors. Available in SIP, DIP, chip, IC, etc. packages.
Resistors that are used to reduce parasitic oscillations or unwanted RF signals that may occur in the output stage of high power amplifiers. Also found in high tension leads of ignition systems to reduce RFI or electrical noise.
Discrete miniature resistors which are packaged without leads and fastened directly to foil patterns of a PCB. Generally found in high frequency design and where space considerations are at a premium.
Surge Resistors
(43 Companies)
Specially designed resistors handling various overloads within a circuit. Withstands transient high voltage impulses and has high heat dissipation, e.g. in noise suppression of engine ignition, overvoltage protection and crowbar discharge applications.
A wire-wound fixed resistor having one or more additional terminals along its length, generally for voltage divider or adjustment applications.
Type of resistor with resistance varying according to its temperature. Widely used as inrush current limiters, temperature sensors, self-resetting overcurrent protectors, and self-regulating heating elements.
Resistors in which the resistance element is a length of high-resistance wire or ribbon wound on an insulating form. Generally found where high-temperature stability, power-handling capability, or low resistance values are required.
Zero-ohm resistor is a wire link used to connect traces on a PCB that is packaged in the same format as a resistor. Similar to jumpers, these components may be packaged like cylindrical resistors, or SMT resistors.
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eeTechBriefs –
15-Minute on-demand multimedia web casts covering the latest product developments.
There are many things to consider when selecting a fuse such as current rating, breaking capacity, derating, trip characteristics, etc. This brief, "Guide to Fuse Selection" discusses the purpose, characteristics, sizes and types of fuses. It includes the why, what and how of selecting the right fuses to comply with regulatory agencies and, more importantly, to protect against safety hazards and equipment failure. Please join Schurter Inc. and Nikila Kareesan, Applications Engineer, for a 15 minute on-demand eeTechbrief webinar covering the Guide to Fuse Selection.
What is SuperSpeed USB 3.0?
SuperSpeed USB 3.0 offers significant performance enhancements, improved power efficiency and greater power delivery options relative to other USB standards, all without compromising compatibility with the billions of USB-enabled devices currently in use around the world. As OEMs look to develop end products with SuperSpeed USB 3.0, many questions arise about the standard's capabilities and other issues such as the availability of hardware to support new designs.
Join Avnet Electronics Marketing's Matt Burns for a brief webcast that will explore the following topics:
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Pluggable I/O interface technology gives designers flexibility and significant advantages for use in high-speed networking, storage and telecom applications. Standard I/O equipment supports fiber and copper links, and provides more data throughput in smaller packaging.
Tyco Electronics continues to be engaged in new pluggable interface standards to support the rapidly changing market needs for higher bandwidth, and remains and industry leader with the technical expertise required to deliver superior designs for signal integrity and EMI at higher data rates. Tyco Electronics offers a full line of pluggable I/O interfaces and continues to be a leader in new product development. The TE Product portfolio includes: SFP, SFP , XFP, X2 and QSFP connectors, cages, heatsinks, light pipes and cable products.
Please join Tyco Electronics’ global product manager, Mike Walmsley, for an eight minute on-demand eeTechbrief webinar covering the application of pluggable I/O products, the interfaces and their features, and the roadmap and challenges for next generation solutions.
3M™ Ultra Hard Metric (UHM) Fully Shielded 2 mm Hard Metric Socket Connectors are engineered to deliver more than 7 Gbps backplane performance for systems based on 2 mm hard-metric connectors. System design engineers working with 2 mm hard-metric-based designs, such as VME or CompactPCI®, can now dramatically increase overall system performance while preserving their existing investment.
3M and Avnet Electronics Marketing are hosting a brief Webcast that will explore the following topics:
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• PICMG Standard 2.30 for the J2 connector
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• Support for legacy 2 mm HM system designs
In less than 14 minutes, you’ll gain an understanding of how standard Compact PCI and VME 64x systems can now support multi-gigabit, high-speed serial IO protocols such as SAS, SATA, Rapid IO, PCI Express and Gigabit Ethernet without costly backplane redesigns or forklift upgrades.
The 3M™ 2 mm Shielded Controlled Impedance (SCI) Cable Assembly Development Kit allows engineers to quickly and cost-effectively assess, test and design a high-performance 2 mm SCI cable-to-board solution for applications that require the proven reliability of latch/eject connectors.
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