From: gherold@teachspin.com   
      
   On Thursday, August 16, 2018 at 10:41:50 AM UTC-4, Terry Pinnell wrote:   
   > The curtain controller I made about 12 years ago toggles the curtains to   
   > open or close on pressing a momentary push button. For holidays I   
   > improvised a circuit based on an LDR inside one of those old mechanical   
   > mains-operated timers. The LDR is flush up against its neon light. That   
   > part of my circuit has recently stopped working and I've started work on   
   > it. But meanwhile I'd welcome suggestions on the *simplest* circuit that   
   > would effectively turn those two long duration LDR states into a short   
   > +12V pulse at each transition. Effectively giving me a parallel   
   > push-button.   
   >   
   > It would be a slog to re-install (and probably re-learn) Circuitmaker   
   > right now, so please excuse this rough hand-written substitute.   
   >   
   > https://www.dropbox.com/s/kejq0ab6jw7go5a/CurtainUnitAddOn-1.jpg?raw=1   
   >   
   > Terry, East Grinstead, UK   
      
   The two states are low resistance in the day with sunlight,   
   and high resistance at night?   
      
   Some comparator with a lot of hysteresis maybe.  ...   
   Maybe a low pass filter in front?   
      
   George H.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)