Hi, Pls, have a look at this description of Signetics 25000 series 9046 XN component: http://pichotjm.free.fr/humr/2.html Can you explain me, what is Vff? Is it a good idea to decrease this voltage in order to increase reliability? But what will happen with our 50 Hz european supply? I need help... (please, answer with simple english) JM Pichot