What would be the most simple and safe way to derive a clean 'Logic High' (for CMOS 4000 series etc), from each segment of any functioning device which has an LCD display? In this case, i'm seeing an AC square wave of about nine volts p.p. per segment. An Intersil ICL7136 chip is driving the LCD display (as it is designed to do) and the system is running off a nine volt battery.
I have a half built 'Veroboard Lashup' I started over ten years ago as an attempt to do the task using a nice little four pin bridge rectifier for each seg. followed by a smoothing cap and it was a good enough signal to present to the CMOS Digital part of the project.
But I really doubt if this is the best approach in terms of the ICL7136's safety or simplicity in the work required to finish this one-off gadget.
I've done a reasonably large amount of searching, but ended up here (as usual) for these sorts of answers.
Any Ideas? Thanks, Mark