How Pierre Curie protects power supplies against blowing (Short Form of the german application sheet). In many cases electronic fuses in the converter ICs take on this protective function against thermal overload, thermo fuses or voltage limitation circuits are used in bigger transformers; whereby the latter do not apply due to their wide input range. Since the current transformers are very small, it is difficult to fit thermo fuses in the coil chambers. The author has developed a safety procedure for DC/DC transformers that takes advantage of the behavior of magnetic ferrites, i.e. that they lose their permeability at a certain temperature. From this temperature on, which is substance-specific for each ferrite and known as the Curie temperature, the relative permeability u_r(B,T) suddenly decreases to 1.

An extract of the Curie application note was published by WEKA Verlag journal „Elektronik“, 5/2001, Germany.

At www.dietmarberndt.com you have a copy of this publication (4 pages in JPEG-Format)