Herbert Graf wrote:
> On Tue, 2011-10-11 at 23:16 -0400, V G wrote:
>  =20
>> Hi all,
>>
>> I want to make a simple, cheap, quick, reliable (no one dare say you can
>> only pick only x) garage door open detector that will light up an LED in=
 the
>> house/beep a speaker if the garage door is open. I know all it takes is =
a
>> mechanical switch, but I'd rather not use any moving parts. I'm thinking=
 a
>> very bright infrared LED and IR transistor with a piece of foil mounted =
on
>> the inside of the garage door. If the door is closed, a series of LED pu=
lses
>> will hit the aluminum foil reflector and bounce back to the IR transisto=
r
>> and signal the device that the door is closed. Will this work? I've neve=
r
>> done any IR work, so I don't really know what power LED is required, wha=
t
>> the distances are, etc.
>>    =20
>
> Unless you interested in learning about that kind of stuff, don't
> bother.
>
> Just get the type of sensor alarm systems use. One end is just a magnet,
> the other is a reed type switch. VERY reliable, VERY cheap. You can find
> them pretty much everywhere. Easy to mount to. That's what I use.
>
> TTYL
>
>  =20
Dollar Tree has them for, get this, $1.  Should be easy to modify to suit.

Kerry


--=20
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