A CdS photocell sounds like a good idea, as long as it is light outside
the box.
Maybe a reflective photosensor like Fairchild QRD1114 (US$0.90 Digi-Key)
looking at the edge of the lid?

Sherpa Doug

> -----Original Message-----
> From: Tim McDonough [mailto:tim@MCDONOUGH.NET]
> Sent: Thursday, April 11, 2002 10:07 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [EE]: Tilt/Position Sensing
>
>
> I'm working on an application where the sensor and electronics is
> mounted in the lid of a container. I want to sense when the lid of the
> container is off or open so that the device can ignore readings during
> this time period. Cost of the sensor/switch is an issue.
>
> My first thought was a mercury type switch like those found in wall
> thermostats. Any idea who makes these?
>
> Other options are a reed switch and magnet but the mechanics of making
> sure it always aligns properly could be expensive.
>
> Another option is a photo sensor since the inside of the container
> would always be dark when the lid is closed. Possible problems could
> be dirt blocking the sensor.
>
> I'm open to other suggestions as well.
>
> Tim
>
> --
> http://www.piclist.com hint: To leave the PICList
> mailto:piclist-unsubscribe-request@mitvma.mit.edu
>
>
>

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu