Hewlett Packard make an opto isolated 4-20mA current loop in an 8 pin
DIP - HCPL4100.  I think there are also linear opto isolators for analog
voltages, but I can't find a reference for them :-(

Tony

PS.  I posted my 16F84 based Programmable Ignition system on the
PicNPoke web site if anyones interested.


PicNPoke Multimedia 16F84 Beginners PIC Tools.

**PLUS** - PicNPlay - PicNPlan - PicNPrep - PicNPost
PicNPort - DT Type Saver - *new* PicNQuiz.
Recent addition - Hex To Source converter.

http://www.picnpoke.com
Email picnpoke@cdi.com.au