Posted by geoff the bonnie on September 26, 2018, 8:04 am
For those interested in automatic switching of lights. Search on ebay for microwave light switch and a round white one will turn up looking like a smoke detector. |
They have adjustment for time, sensitivity and an adjustment to make it work just when it gets dark. (light level). These are just tiny plastic screws within the unit.
They need a L and N plus a switch wire to the lamp.There are many ways to wire these in and can be fitted to existing wiring and just leave the light switch on. They only need a switch to comply with isolating for maintenance.
Mostly,they need to pick up a movement so need to be in sight of a moving object. They will operate through closed doors or glass so need a little planning for placement. Solid walls will not allow operation.
I have these in various places including the garage where it will switch on multiple lighting and a radio tuned to radio 5 to give an impression of someone being in the garage. You could use it to operate a loud siren, in fact,it will just switch most mains operated equipment or light fittings.
These are better than the old PIR type as you cannot creep up on the detector. Fit inside a garage by the window and it will turn on the lights.
When wiring up,the unit does not need an earth wire but to comply with regulations, there must be an earth wire for testing purposes.Just fold it over in the earth Green/yellow sleeving.
They cannot be used outdoors if buying this type but there are waterproof versions.
I have found that used outdoors,they are too sensitive and will turn on lights if leaves blow or its windy plus animal movement. Ideal if covering a sheltered area.
If fitted on a landing of an average house,it will switch a light when coming out of any bedroom. My landing is 20 foot long and it also picks up on you at the bottom of the staircase as long as the unit is in direct line above the stairs.
I see they are now less than 8 pounds but be aware that some are posted from China. They are all the same so price is the only consideration when buying.
When these came out about 15 years ago, they cost well over 100 pounds. I used the expensive ones in schools so there were no wall switches for the kids to play with. The other benefit is that when school finished, no one had to go around switching lights off.
If you do buy one and have any question about fitting, i will help out as many of you know, i am an electrician from leaving school so 50 years of practice.