At 11:26 AM 5/9/2006, alan smith wrote: >This is a busy week for....what/how games I suppose.... > > > Want to detect not that a device is plugged into a socket...but > look to see if its turned on...ie.....is the device drawing any > current, thus its running. > > Initial thoughts.....hall sensor that drives a bridge and then > look for a DC threshold value. (hall sensors used for AC current > detect will mimic the AC waveform and increase the amplitude as > more current passes thru the field while also provide isolation). What kind of volume do you anticipate? The toroid coil used in standard GFCI wall outlets will do what you want - they are sensitive (maybe even too sensitive) and saturate easily so as to not damage your detector circuit. I know these can be had very cheaply *if* you are purchasing thousands. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 22 years of Engineering Innovation (1984 - 2006) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist