From: whit3rd@gmail.com   
      
   On Saturday, August 24, 2019 at 12:12:56 PM UTC-7, Terry Pinnell wrote:   
   > Pressing the door button of my commercial wireless door bell causes the   
   > mains-powered speaker unit in the hall to chime. Rather than buying another   
   speaker   
   > unit I thought I'd make a simple extension ...   
      
   > I was playing with connecting that pair to a simple audio amp powering a   
   newly   
   > located speaker in my workshop. That's when I quickly discovered (the hard   
   way!) an   
   > obvious flaw in my idea. Both wires were at half mains voltage above earth.   
      
   Easiest way out of that would be an optoisolator solution (there are   
   dual isolators that can be used with some feedback to transmit analog   
   signals).   Or, using either a relay or digital optoisolator, you can trigger   
   a sound-playback of your choice (there are a number of battery toys   
   at the local dollar store that do sound effects).   Heck, there's greeting   
   cards that can be programmed to replicate your favorite annunciator's   
   sound.   
      
   When light-dependent players were built into Christmas-y coffee mugs, an   
   EE of my acquaintance noted that she could 'fix that' with her microwave oven.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)