A series of resistors has been developed by Epcos that are designed for applications as charging resistors for link-circuit capacitors in industrial power supplies, frequency converters and UPS systems. These charging resistors are manufactured from barium titanate ceramic material and can replace conventional ohmic charging resistors. Their advantage is that they strongly limit the current in the event of malfunctions in the charging circuit, such as a short circuit.  The J20X series currently covers voltages of 550 V (J201), 650 V (J202) and 800 V (J204) with rated resistances of 20 Ω, 56 Ω and 100 Ω. Several discrete resistors can be connected in series or in parallel depending on the charging energy of the capacitor and the required charging time constant.