| 摘要 |
A self-resetting circuit overcurrent protection device suitable for use as a replacement for a conventional cylindrical fuse has at least one semi-tubular positive temperature coefficient (PTC) element surrounded by a tubular, electrically insulating body and connected to terminal caps disposed at either end of the cylinder. In a first embodiment of the invention, first and second PTC elements are disposed such that the concave surfaces thereof are oriented toward one another and are connected in electrical parallel so that the hold current of the PTC device is equal to the sum of the hold current values of each of the two elements. In a second embodiment, a first pair of semi-tubular PTC elements are disposed in nested, concentric relationship to one another and a second pair of semi-tubular PTC elements are disposed in nested, concentric relationship to one another, the two pairs of PTC elements being disposed with concave surfaces thereof facing one another. The four PTC elements are connected in electrical parallel so that the hold current of the device is equal to the sum of the hold currents of the four component PTC elements.
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