On 7/11/08, Geo wrote: > On 11 Jul 2008, at 17:22, gardenyu wrote: > > > Yes, the attached schematic works and is reasonable. > > No - it will go bang if you connect a diode from line to earth. That's not "earth" nor 'neutral". Is just a symbol representing the ground of the circuit (where ground = reference for measured voltages). > The earth symbol is incorrectly used in your example. > > > but another similar design does not have this ground at all. The circuit just survives between a higher voltage and a lower one, which is floated.I wonder if the chip can have a ground reference which is not pure ground. > > A circuit only needs to be a contionous to work. Ground is irrelevant. Think > flashlight. > > George Smith > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist