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Thread ID: 69209 2006-05-25 10:05:00 light/movement activated driveway 'doorbell' Johnnz (7246) PC World Chat
Post ID Timestamp Content User
457691 2006-05-27 01:06:00 Looks a good choice, it appears to have a good range.

The only issue I get is false triggering after a frost, as the reflector mists up.

You would want to deactivate the internal buzzer if you want it as a silent alarm, or any local brats will purposely trigger it if they are able to make it sound off out at the gate.

Nobody knows ours is there basically.

Our house insurance company gave us a discount for having it, as a bonus.
godfather (25)
457692 2006-05-27 04:02:00 "... I intend to dig out a cavity in a large fence post and spray/paint the interior with some waterproofing compound then mount a tinted plate of glass in front to seal it in."

Make sure it works through the "tinted glass" before you seal it into the post.
Infrared can be fussy about what it goes through. ;)

I'd be inclined to make it a rainproof, well drained cavity, rather than trying to seal it. Condensation is a killer of electronic stuff (especially high impedance circuitry like an IR sensor). If it's sealed you'll see drops of water on the inside of the glass sometimes. :(
Graham L (2)
457693 2006-05-27 09:02:00 Thanks for highlighting that issue GrahamL. Would putting a sachet of desicant inside the sealed enclosure be enough to prevent condensation issues do you think? I'm just worried insects might cause problems too if there is access to the electronics via a dranage cavity. Johnnz (7246)
457694 2006-05-27 09:18:00 I'll be using Selly's All Clear for lining the inside of the fence post cavity as it was the only one I could find suitable for use on timber. Johnnz (7246)
457695 2006-05-27 11:42:00 Thanks for highlighting that issue GrahamL. Would putting a sachet of desicant inside the sealed enclosure be enough to prevent condensation issues do you think? I'm just worried insects might cause problems too if there is access to the electronics via a dranage cavity.

A sachet of dessicant would be effective for about a day or two, then it would be fully moisture laden with exposure to the air in that manner. Hence I opted for a fully sealed and weatherproof unit.

Your main challenge will be to keep it out of the weather and the livestock, as it could indeed be compromised for IR by covering with glass etc, the glass will also fog as the reflector does, but about 10 times worse.
godfather (25)
457696 2006-05-27 11:53:00 Get a dog ninja (1671)
457697 2006-05-27 22:46:00 Life gets tedious,don't it? Cicero (40)
457698 2006-05-28 00:37:00 A sachet of dessicant would be effective for about a day or two, then it would be fully moisture laden with exposure to the air in that manner. Hence I opted for a fully sealed and weatherproof unit.

Your main challenge will be to keep it out of the weather and the livestock, as it could indeed be compromised for IR by covering with glass etc, the glass will also fog as the reflector does, but about 10 times worse.

Hmm. Thanks for all the tips. I'll let yall know how I get on later...
Johnnz (7246)
457699 2006-05-28 00:38:00 Get a dog

I agree. but Im doing the job for someone else :)
Johnnz (7246)
457700 2006-05-29 13:24:00 I'll be using Selly's All Clear for lining the inside of the fence post cavity as it was the only one I could find suitable for use on timber.


Please don't, that stuff is crap. Use a sealed plastic box or/and as suggested one that drains (out the bottom only). To seal the glass in place, either use something with a screw on flange and seal or use glazing silicon which will adhere to the glass and plastic equally well or a sanitary sealant (one with a fungicide will last longer. Sanitary: bathroom/plastic or tile sealant).

BTW, most of the silicons will stick perfectly well to clean timber as will a MS type, which you don't want to use on glass or clrear plastic.

As you were.
Murray P (44)
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