Homebrew PCBs

On Mon, 14 May 2007 13:33:04 +0200, Paul Sturpe <sturpe@...>  
wrote:

>
> Can the paper sensor be purely mechanical in nature?


It's usually a little mechanical pivoting plastic lever/flag working a  
fork type photointerruptor.
I have taken apart some old dot matrix printers which used direct  
reflective photo sensors on the paper, but usually it has a mechanical  
lever.

ST