NTC THERMISTOR What are NTC Thermistors? thermistor integrated in a stainless steel probeNTC stands for "Negative Temperature Coefficient". NTC thermistors are resistors with a negative temperature coefficient, which means that the resistance decreases with increasing temperature. They are primarily used as resistive temperature sensors and current-limiting devices. The temperature sensitivity coefficient is about five times greater than that of silicon temperature sensors (silistors) and about ten times greater than that of resistance temperature detectors (RTDs). NTC sensors are typically used in a range from −55 to +200 °C. The non-linearity of the relationship between resistance and temperature exhibited by NTC resistors posed a great challenge when using analog circuits to accurately measure temperature. However, rapid development of digital circuits solved that problem through enabling computation of precise values by interpolating lookup tables or by solving equations which approximate a typical NTC curve. Features : This is a Negative Temperature Coefficient Resistor Whose resistance changes with ambient temperature changes. Thermistor comprises 2 or 4 kinds of metal oxides of iron, nickel, cobalt, manganese and copper, being shaped and Sintered at high temperature(1200℃ to 1500℃ ) Applications : Conversion power supply, switch power, UPS power, Kinds of electric heter, electronic energy-saving lamps, electronic ballast etc all kinds of power cicuit proterction of electronic equipments, filament proterction of CRT, bulb and other lighting lamps. Part Numbering System : *NTC - Negative Temperature Cofficient Resistor. *10 - Resistance Value:10Ω *D-13 - Diameter of Chip: Φ13 Critical Technical Parameters of NTC Thermistor : * Rt---Resistance Value at Zero-power It's a resistance which is got at a fixed temperature on a basis of a testing power which causes resistance to Vary in a range which can be ignored in relation to the total testing eror. * R25---Resistance Value at Rated Zero-power The design resistance of the thermistor usually refers to the resistance value got at Zero-power at 25℃ , which is usually indicated on the thermistor. * Max. steady state current.Imax. The maximum allowable continuous current passing through thermistor at 25℃. * Dissipation Coefficient δ It's the ratio of the changes with a thermistor dissipation power, in a pre-set ambient temperature, to the changes with the temperature. The formula is as below:δ = △P/ △T , δ changes in response when the ambient temperature changes, within the ranges of the working temperature. Disk and Chip thermistors : These NTC thermistors have metalized surface contacts. They are larger and, as a result, have slower reaction times than bead type NTC resistors. However, because of their size, they have a higher dissipation constant (power required to raise their temperature by 1 °C). Since the power dissipated by the thermistor is proportional to the square of the current, they can handle higher currents much better than bead type thermistors. Disk type thermistors are made by pressing a blend of oxide powders into a round die and then sintering at high temperatures. Chips are usually fabricated by a tape-casting process where a slurry of material is spread out as a thick film, dried and cut into shape. The typical sizes range from 0.25 to 25 mm in diameter. Full range of Thermistors are available with us, for best quotes contact, SURAJ ELECTRONICS , MUMBAI