PTC thermistor having a positive temperature coefficient (TC) and are therefore called (PTC = Positive Temperature Coefficient) and PTCs. Their resistance increases with increasing temperature. They consist of doped ceramic materials based on barium titanate. If current flows through the PTC, it heats up. Thereby its resistance increases. This behaviour can be utilized inter alia for the purpose of over-current limit and time delay. Other areas of application: the turn-brief pulses of current (e.g. for degaussing colour picture tubes or starting of induction motors) and the use as a heat source (heater).
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