Self-protecting power resistors PTC thermistors in plastic case Series/Type: B5920* Date: June 2008 © EPCOS AG 2008. Reproduction, publication and dissemination of this publication, enclosures hereto and the information contained therein without EPCOS' prior express consent is prohibited.
Self-protecting power resistors PTC thermistors in plastic case J201, J202, J204 Applications Inrush current limiter (charging resistor) for smoothing and DC link capacitors To replace high-power fixed resistors for capacitor charging Dimensional drawing Features Self-protecting in case of malfunction of short-circuit relay or internal short-circuit of capacitor Encased thermistor disk with clamp contacts For high pulse currents and a high number of operating cycles Flame-retardant plastic case Case mat
Self-protecting power resistors PTC thermistors in plastic case Characteristics Minimum resistance of PTC thermistors versus applied voltage Switching time tS versus switching current IS (measured at 25 °C in still air) Please read Cautions and warnings and Important notes at the end of this document.
Self-protecting power resistors PTC thermistors in plastic case J201, J202, J204 Calculation of the number of required PTC elements Number of required PTC elements (connected in parallel) as function of capacitance and charging voltage of smoothing or DC link capacitor: N Number of required PTC thermistors connected in parallel C Capacitance of smoothing or DC link capacitor in F V Charging voltage of capacitor in V Cth Heat capacity in J/K Tref Reference temperature of PTC in °C TA,max Expect
Self-protecting power resistors PTC thermistors in plastic case J201, J202, J204 Cautions and warnings General EPCOS thermistors are designed for specific applications and should not be used for purposes not identified in our specifications, application notes and data books unless otherwise agreed with EPCOS during the design-in-phase. Ensure suitability of thermistor through reliability testing during the design-in phase.
Self-protecting power resistors PTC thermistors in plastic case J201, J202, J204 Operation Use thermistors only within the specified temperature operating range. Use thermistors only within the specified voltage and current ranges. Environmental conditions must not harm the thermistors. Use thermistors only in normal atmospheric conditions. Avoid use in deoxidizing gases (chlorine gas, hydrogen sulfide gas, ammonia gas, sulfuric acid gas etc), corrosive agents, humid or salty conditions.
Important notes The following applies to all products named in this publication: 1. Some parts of this publication contain statements about the suitability of our products for certain areas of application. These statements are based on our knowledge of typical requirements that are often placed on our products in the areas of application concerned.
