How to Select PTC thermistors for Over Current Protection
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Items to be checked
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Selection criteria
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| How much (in volts) is the power supply voltage of the circuit in which PTC thermistor is used? (Preventing PTC thermistor from being damaged) |
-> | Power supply voltage ≤ Maximum voltage of PTC thermistor |
| When the circuit is operating normally, how much (in amperes) is the current that flow through PTC thermistor? (Preventing PTC thermistor from malfunctioning) |
-> | Normal current ≤ Non-operating current of PTC thermistor |
| When something abnormal such as a short circuit has occurred, how much (in amperes) is the current that flows through PTC thermistor? (Ensuring reliable protection) |
-> | Abnormal current ≧ Operating current of PTC thermistor |
| PTC thermistor application environment condition, esp. ambient temperature | -> | PTC thermistor reference temperature (also called Switch temperature or Curie temperature) >maximum operating ambient temperature |
