Tag Archives: clock

Curtain Clock

clock5I’ve never been a morning person.  But, I’ve found the best way to wake up is with natural light. These indoor solar simulators hold no candle to the bright sunlight on a clear morning.  My solution was an alarm clock to draw back the curtains.

This device mounts to the wall beside the window, neatly hidden behind the curtain edge when open or closed.  The alarm from a clock assembly (pulled from an old programmable coffee machine) triggers a 555 timer acting as a monostable oscillator which drivers a relay-controlled synchronous AC gear motor that draws the curtains closed via a cord.  The 555 pulse length must be set as to generate the correct fixed opening time.  It is also a good idea to have a torque-limiting clutch (ie, find a bobin that fits tight to the motor shaft that will slip if there is a jam).

I built this at the end of 2008, but never really documented it.  It works well, but I would like to redesign it to automatically find the full open position.

 

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