Russell McMahon paradise.net.nz> writes: > Your bridge system is eminently more practical. The bridge actually works by creating a deliberate heat leak and then instrumenting it and trimming the leak to nearly zero. This is why the two sensing thermistors have to be coupled in series and insulated. Peter P. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist