Passive Components ABOUT BÜRKLIN Our services: 75.000+ articles from stock in Munich Bürklin Elektronik is the leading distributor in Europe for high-quality electronic components and support Delivery promise: Same day shipping for all orders received by 6pm services for the Industrial Automation, Robotics and Process Technology Markets, with our Headquarters and Online Shop: buerklin.com Warehouse in Oberhaching near Munich. In 2019 we are celebrating our 65th year in business. Free reeling service Strong Linecard with well-known and reliable brands Bürklin Elektronik offers you the complete product range of passive components for your current application eProcurement solutions (OCI, API, electronic catalogs, EDI) requirements. From resistors to capacitors, varistors, thermistors, potentiometers, trimmers, suppressor filters, inductors and ferrites, you can obtain all these products directly and quickly from our warehouse in Germany. We are continuously mapping all current product launches on the market and exclusively carry stan- dardised and tested quality products from leading industrial manufacturers worldwide. With a modern placement machine (Pick-and-Place), up to 50 different SMD components can be accurately placed at high speed in their allotted space on the printed circuit board. RESISTORS A Resistor is a passive electrical component found in almost all electrical networks and electronic circuits. Resistors are used in various applications like delimiting electric current, voltage distribution, matching circuits, gain control etc. low Resistance value is measured in Ohms and is calculated as the ratio of the voltage to current. The manufac- turing accuracy is indicated with tolerance in percentage. Other important parameters include temperature Film Resistor coefficient and long term stability. Further deciding parameters could include mounting, size, capacitance and parasitic inductance. Wirewound Various types of resistors exist in the market based on technology, ratings and sizes. They include wire-wound Resistor resistors, Metal film resistors; thick and thin film resistors etc. TCR Thin-film Resistor Thick-film Resistor high high Durability CONDENSORS Power Electronics Power Metallized Capacitors Film Capacitors Energy Film Storage Capacitors Aluminium Ceramic Electrolytic The name is derived from the Latin “condensare” = compress - it stores static energy in an electric field. The Capacitors Capacitors stored charge per applied voltage is measured in “Farad” units. In addition to the two conductive electrodes, Tantalum the dielectric used (the storage mass) is the essential component of a capacitor and gives it its name: Capacitors Coupling Ceramic Double-Layer and HF Capacitors Capacitors In aluminum electrolytic capacitors (also called “electrolytic capacitors” for short); the anode consists of (HighCap) Niob and Modules roughened Aluminium. This allows a large surface area to be achieved, which ensures a high capacity. The Power Supply Capacitors surface is anodized and the resulting insulating oxide layer forms the dielectric of the capacitor, this serves oltage V as the cathode or negative plate of the capacitor. Electrolytic capacitors are mainly used in power electronics. They reach capacities up to 1 Farad at voltages up to 5000 V and higher. Capacity A modern counterpart to the aluminum electrolytic capacitor is the polymer electrolytic capacitor. Here the aluminium is the anode is also roughened and oxidized to the dielectric. However, the cathode is a solid, con- ductive Polymer that adapts to the surface structure. Also mixed forms of capacitor with a combination of solid Polymer and liquid electrolyte are present (hybrid capacitors). With ceramic capacitors, the dielectric is made of ceramic and can also be applied in several layers. (Multi- Layer Ceramic Capacitors = MLCC). Their capacities are in the pF to 100 μF range. They are often used for Film capacitors have dielectric insulating plastic films, which can be wound or stacked, their great advantage high-frequency couplings and in power supplies. The tiniest MLCCs (the smallest SMD capacitor with size 01005 is self-healing: where other capacitors are often damaged when the voltage is too high, the “film caps” can has an edge length of less than 0.5 mm) are used in high voltage applications; they are also used for control have “self-healing” properties in that dielectric breakdowns or short circuits between the electrodes do not electronics in automobiles and mobile devices. Ceramic capacitors also come in the “classic” disc design with necessarily lead to the destruction of the component. They are used for radio interference suppression and connecting wires. are used as DC link capacitors. VARISTORS THERMISTORS A thermistor is a thermally sensitive resistor that is used as a sensor for temperature measurement. There are usually two types: NTC (Negative Temperature Coefficient) and PTC (Positive Temperature Coefficient). The resistance of the NTC thermistors decreases with increasing temperature coefficient, while the resistance of the PTC thermistors increases as the temperature rises. Thermistors are used in a variety of applications such as voltage regulation, circuit protection, temperature control, digital thermometers, automotive etc. Some heavy duty thermistors are suitable for immersion in corrosive liquids and can also be used in industrial processes. The general criteria for selecting a thermistor are usually the base resistance, the temperature range, the stability, the thermistor packaging, etc. A Varistor or „VARIable resiSTOR“ is a component used for overvoltage protection in electrical and electronic equipment. The Varistor resistance changes from a very high stand-by value to a very low conducting value. In normal operation the Varistor has a very high resistance, if the voltage rises above the nominal value, its effective resistance drops sharply and increases the leakage current over the Varistor. This helps to control the transient overvoltage across the device. The most common type of Varistor is the metal oxide Varistor or MOV. The resistor material is a metal oxide, which is pressed into a ceramic material. MoV‘s are very effective at absorbing faster voltage peaks and have higher high-voltage strength. POTENTIOMETER AND TRIMMER SUPPRESSION FILTER Interference suppression filters are used not only to prevent spikes and overloads in machines and equip- ment that occur when they are switched on, but also in operation so they cannot be fed back to the general grid. Conversely filters protect both interference suppression filters and devices from voltage peaks. Even high-frequency interference and active and passive harmonics are effectively blocked by suppressor filters in accordance with the application, and thus avoiding malfunctions and overheating in the system The most common type of a potentiometer is the single turn rotary potentiometer or “Trimpot”. Other types of potentiometers are multi-turn, dual-speed, slide, Servo potentiometer etc. The other type of classification of a potentiometer consists of the resistance changes with the movement, also known as a potentiometer cone. Potentiometers can be converted in this way into linear, A potentiometer is a passive component, whose re- logarithmic and negative logarithmically types. sistance value can be set manually. As a rule, a poten- tiometer has three terminals, two of the terminals are A trimming potentiometer or a trimmer is a potentio- connected to both ends of a resistance and the third meter for tuning and calibration in circuits. Trimpots is connected with a sliding contact, which is moved via are used as a rule for occasional setting, and have a the connected resistance element. The potentiometer high resolution. The setting is made with a screwdriver is essentially a voltage divider, whereby the output and can be used in single or double multi-turn version. voltage is determined by the position of the sliding Single-turn Trimpots are cost effective and frequently contact. used when a resolution of one revolution is enough. For applications where a higher resolution is required, multi-turn Trimpots are used. INDUCTORS FERRITES Ferrites in electrical engineering are solid moulded components made of soft magnetic metal oxides, which can be used as cores for chokes (see Inductors on previous page). They can be available in various forms for Example: ring-shaped (for toroidal core chokes), as E- or U-core or rod-shaped (I-core). In SMD designs fer- rites can also be used directly to attenuate interfering high frequencies in circuits. As perforated cores, they are applied directly to cables to ensure direct filtering. Using the AL value, which depends on the material of the ferrite core and its shape and is determined by the manufacturer, the inductance can be calculated with the desired number of turns. Inductors and chokes are - in addition to capacitors and resistors - a component found in almost every electrical system. An inductor or choke consists of a wire wound around a coil carrier. Ferrite is often used to form the core - so the number of necessary turns can be reduced. Alternatively flat coils can be stacked on top of each other in several layers. Inductors are used in signal processing or used as energy storage in switched-mode power supplies and can be used for filtering or impedance matching. As an interference suppression element, e.g. direct currents should be influenced as little as possible, high-frequency alternating currents are filtered