Transformers for Printed Circuit BoardsTransformers conforming to VDE 0570/IEC 61558, UI or toroidal core, with terminals in the form of solder pins, immersion-impregnated or encapsulated in plastic receptacles. The required pin assignment must be specified on ordering.
Series PF which is of extremely flat construction is particularly suitable for use on plug-in cards. In the standard version of series PF an PS the clearance and creepage distance as well as the test voltage conform to VDE 0570. Transformers of these series are not short-circuit-proof and measures against overloading and short-circuit must be taken by the user.
Series PS transformers can be supplied with built-in PTC thermistor which makes them non-inherently short-circuit-proof. In the event of overloading, the PTC thermistor limits the primary current. After eliminating the overload and after cooling, the transformer is ready for operation again.