Ametherm SG250

Negative Temperature Coefficient (NTC) thermistors are thermally sensitive semiconductor resistors which exhibit a decrease in resistance as absolute temperature increases. Change in the resistance of the NTC thermistor can be brought about either by a change in the ambient temperature or internally by selfheating resulting from current flowing through the device. Most of the practical applications of NTC thermistors are based on these material characteristics. RTI manufactures SURGE-GARD™ Inrush current limiting devices using specially formulated metal oxide ceramic materials. These devices are capable of suppressing high inrush current surges. They are especially useful in power supplies where the low impedance of the charging capacitor exposes the diode bridge rectifier to an excessively high current surge at turn-on.

• Lowers rectifier cost by reducing required peak forward surge current rating
• Reduces Noise
• Reduces Fuse Failures
• High Current Capability

• The most popular application is the inrush protection of the AC current in switching power supplies (SPS).