| 摘要 |
<p>Circuit protection systems which comprise a PTC resistor (1) and a second resistor (6), e.g. a thick film resistor (6), which is thermally and electrically connected to the PTC resistor have a break current IB and a hold current IH such that the ratio IB/IH is at most 20. Suitable PTC resistors (1) are conductive polymer devices which comprise a PTC element (10) which has been radiation crosslinked under conditions such that the average dose rate is at most 3.0 Mrad/minute or during which no part of the PTC element (10) which is in contact with the electrodes (2, 3) reaches a temperature greater than (Tm-60)°C, where Tm is the melting point of the polymeric component of the conductive polymer (10).</p> |
