outdoor pir lanterns?

[Sam]

Hi,

We have a small passageway along the side of the garage. I'd like to put a light or two down there. Is there a rough rule along the lines of "you need one light every x metres"?

Do PIR lights only work with filament bulbs rather than CFLs? I'd like to use CFLs because they have lower running costs, though I suppose they would be no good for security because they take forever to warm up!

Do all exterior lights have the cable enter through the back? I suppose rear entry is good for security; it prevents burglars cutting the wire and I suppose because the wire is hidden it looks pretty. However if security is critical and appearance not important, I would have though dropping a wire down the all and into the top would be the quickest and easiest thing to do?

Thanks in advance.

[cj]

Hi For domestic use no rules apply really for spacing it comes down to common sense. As for lamps most modern pir activated lights that take a std lamp use relay switching so any lamp that does not overload the rated current will work.(I have 3 all with energy saver 7w lamps [2 for 99p at my local supermarket])

You may also consider 1 stand alone pir sensor at the end of the corridor wired to several fittings along the wall.

Re entry points whilst security and looks play a part its Gravity that stops people wiring into the top of external fittings. Water runs down the cable into the fitting and even if a good grommet or sealer is used , can still builds up on the top of the fitting around the cable entry.

HTH

CJ

[Sam]

The relay would explain why they click as you approach.

So why do they say "not for use with CFLs"?

Yes, and I suppose that a bottom entry with wire coming down, forming a drip-loop beneath the lamp, and then entering would look silly.

[Mike Clarke]

Because of the time that CFLs take to reach full brightness. Ours comes on as someone approaches the front door so people don't fall down the steps in the dark. If we used a CFL they'd have fallen down the steps before they could see them.

Also the frequent short on cycles will reduce the life of a CFL.

Depends if you prefer silly or safe, I prefer safe.

[Sam]

My point was that the rear entry is both safe and not silly looking.

[geoff]

In message , Sam writes

????

[David Hansen]

On Fri, 23 Nov 2007 16:03:41 GMT someone who may be Sam wrote this:-

Decide whether you want lights that are on from dawn to dusk or ones that react to movement. If the former then go for energy saving lamps, if the latter go for filament bulbs.

Personally I would go for the former.

[Sam]

Why's that? I'm the opposite; I'd prefer them to come on only when they are needed. This is for down a passageway so I think we only need them to come on as required, which is rarely.

Thanks.

[David Hansen]

On Mon, 26 Nov 2007 19:48:44 GMT someone who may be Sam wrote this:-

Gentle illumination deters, darkness does not.

Also the sudden appearance of bright light is not great for night vision.

[Chip]

On Sat, 08 Dec 2007 23:31:37 GMT,it is alleged that "The Medway Handyman" spake thusly in uk.d-i-y:

[Snippage]

From my experience at a friend's house yesterday, yes they work through modern sealed double glazing units. The range may be reduced though.

I'm not sure what effect low emissivity glass (such as Pilkington K glass) would have, as ISTR this blocks (or attenuates) IR.

[cj]

Hi Sorry to dissapoint but a PIR will not see through windows. PIR= Passive Infra-Red detector. Basically they look for a change in infra-red light (heat) so unless you are shining a heat lamp through the window nothing will happen .(if it did a lot of alarms would be going off everytime the windows were cleaned.)

CJ

[The Medway Handyman]

Interesting. I bought a couple of those plug in nightlights for my granddaughters room recently. They have three settings, one of which is 'motion'.

They specifically refer to 'motion' detection in the instructions not PIR and do seem to detect just motion - e.g. waving an inert object in the detection path, or throwing a soft toy across the path triggers the light.

How do they work then?

[cj]

The most common in the alarm industry are :- PIR Passive infra-red Point to point .Active infra-red (like the lasers on tv) Ultra-sonic .high frequency sound (usually around 45kHz) Microwave. Like a radar speed trap. Or a combination of the above in the same detector. To name but a few.

Your unit sounds like it may be ultra-sonic ,nearly obsolete in the alarm game so often used in other aplications. (parking sensors on BMW's and the like). They used to be known as 'Air' sensors.

CJ