replace ordinary light switch with one with 7-day timer?

[FrodoOne]

Having been hunting on this subject for about 4 hours now and beginning to get a bit frazzled. There's a question here dating from 2009.

First points: the is about security, warding off potential burglars when I'm away.

How about just obtaining a "Random Light Timer"
(such as one of these at (https://www.amazon.co.uk/s?k=random...x=random+light+timer,aps,418&ref=nb_sb_noss_1 )
and plugging into it a standard lamp - or whatever.

 

[ericmark]

First points: the is about security, warding off potential burglars when I'm away.

I am of two minds on that, any visible security can ward off, or invite, saying look I have some thing worth pinching, security lights to stop the burglars tripping over is very considerate, but if a neighbour knows your away, and sees lights in the house, it will alert them some ones in the house, but if lights switch on random, then the neighbour will ignore lights.

Some smart lighting does have the option of setting random switching between dusk and dawn, noticed it on some apps, but never used the option, I have used the switch on at dusk option for living room lights (Tapo [TP-Link] light switch) as I had a habit of nodding off after tea watching TV and waking up to find TV timed out, in total darkness. However I can always say hey google turn lights on so not really necessary any more.

A plug in time at under £5 seems the simply way, with a standard or table lamp plugged in. Tapo Smart Light Switch, 1 Gang, 1 Way - TAPO S210 at £17.70 and hub also at £17.70 is £35.40 which is not cheap, for me well worth while, as I use the voice commands a lot, but cheapest I have found a Nest Mini is £25 and Alexa £35 we did not buy the Nest Mini to use voice commands, we got it as no VHF radio were we live.

We started with smart devices so we could combine timed events and remote control for an extruder alarm, so we knew when mother had gone on wheel about. (She was in a wheel chair) and over the years it has expanded.

 

[Deluks]

This...

Cheap, easy to install, you can turn it in and off remotely, you can set a schedule in the app to dictate when it turns in and off.
You just need a WiFi connection and a smartphone.

Their cameras are great too, you can view the camera and operate the lights all in the same page on the app.

 

[JohnW2]

Pretty lazy comment. You obviously didn't bother reading the next post after Harry Bloomfield reminded me of the (obvious) situation in a light switch. More likely you **did** read it but are determined to rant anyway to show what a saddo you are.

Yes, I did read your subsequent posts, but they merely reinforced my view that it would be useful (to you) for me to point out that you appeared to be over-estimating your knowledge/understanding (e.g. when in your next post you talked about "switched live in and switched live out" - which, again, Harry corrected).

As you subsequently wrote, it might possibly be that you really did 'understand', but were expressing yourself in a manner that seemed to indicate otherwise - but I have (and had) no way of knowing whether that was the case.

Whatever,the important point is that you presumably now do understand all these things, whether you did or did not previously.

 

[flameport]

I went and had a look at that site. I'm a bit puzzled what those illustrated little devices actually do. Do they sit inside an existing light switch? So do they contain a battery? How do they in fact interact with the switch itself?

It's a box with a relay inside, and various other components so it can connect to wifi and have programming stored in it.
The relay is what turns the light on and off.

They can be installed behind light switches if you have a neutral there. Your switch does not have a neutral so it would go at the light fitting.
There is no battery, they require permanent power.
A normal switch is connected to it so that operating that switch controls the relay which turns the light on and off. This allows the use of a normal light switch even when the wifi connection has failed.
The relay can also be turned on and off from the internal programming, or when it receives radio signals from other devices.

The blue one linked to earlier is the most basic, with just on/off as the function.
Others have multiple switched outputs, dimming control, power monitoring and various other features.

 

[MRodent]

It's a box with a relay inside, and various other components so it can connect to wifi and have programming stored in it.
The relay is what turns the light on and off.

They can be installed behind light switches if you have a neutral there. Your switch does not have a neutral so it would go at the light fitting.
There is no battery, they require permanent power.
A normal switch is connected to it so that operating that switch controls the relay which turns the light on and off. This allows the use of a normal light switch even when the wifi connection has failed.
The relay can also be turned on and off from the internal programming, or when it receives radio signals from other devices.

The blue one linked to earlier is the most basic, with just on/off as the function.
Others have multiple switched outputs, dimming control, power monitoring and various other features.

Sorry, really showing my ignorance here, but with a "no-neutral" switch, as in my case, what do you mean by "it would go at the light fitting"? Do you mean somehow attached to the ceiling pendant? Does this mean that you have to wire it up in the wires above the plasterboard of the ceiling?

Or does it somehow get fitted with the cable which hangs down from the ceiling? ... except again I don't see how this would work without a battery, which you say it doesn't have.

If "above the plasterboard", could you possibly point me in the direction of a wiring diagram, if it's not too much trouble? This arrangement potentially involves a bit of hassle of course, but on the other hand I like the idea of a device which is not reliant on a battery.

Can this sort of device potentially work with 1) low-energy bulbs? 2) LED-style downlighter bulbs? I suppose the problem with some lighting setups is that one 1-gang switch may in fact control 10 LED downlighters: would I have to have one of these devices for each downlighter?

Not having looked into LEDs for some time I'm not clear what sort of voltage/current they typically run on these days. As far as you know, are these devices in any way constrained by available voltages and/or currents?

At the moment I don't have LED downlighters but I am thinking of improving my place at some time in the future, extension, etc. Maybe this can be incorporated into the plans BEFORE the downlights are installed so that one device controls many downlighters? (Though you'd want access to be non-impossible for when the device flakes out and has to be replaced ... maybe extending the neutral cable and dragging it down into the light switch might be as feasible as anything else?).

 

[flameport]

Does this mean that you have to wire it up in the wires above the plasterboard of the ceiling?

Yes.
If it's just a pendant, then a box will be required in the ceiling above the pendant. Example: https://www.screwfix.com/p/appleby-1-gang-dry-lining-circular-knockout-box-35mm/90517
If it's some other fancy light fitting, it can usually be installed inside the fitting itself. These modules are tiny.

That's an EU type of switch and box but the scale is the same as UK versions.

Or take a neutral to the light switch and fit behind the light switch.
They can theoretically be used with no neutral but that's the same problem as other devices which claim such things - additional 'bypass' or load devices are needed, and even then operation is likely to be unreliable or cause LED lamps to flash or glow dimly.

If "above the plasterboard", could you possibly point me in the direction of a wiring diagram, i

It's the same wherever it goes.
Permanent power L&N, and a switched L output to the light.
Then two wires to the light switch.
All of which should be available at the ceiling light unless some buffoon has used hidden junction boxes.

Can this sort of device potentially work with 1) low-energy bulbs? 2) LED-style downlighter bulbs? I

Yes. LED are low energy and are pretty much all there is now.
Those fluorescent affairs from some years ago are obsolete. No one uses them.

one 1-gang switch may in fact control 10 LED downlighters: would I have to have one of these devices for each downlighter?

You could, if you wanted to control all of them separately.
In reality it's more likely to just switch all 10 just as with any other switch.

Not having looked into LEDs for some time I'm not clear what sort of voltage/current they typically run on these days.

230V AC, and the current is pretty much nothing.
A typical LED downlight is around 5 watts. A 6 amp lighting circuit could have well over 200 of them.
That Shelly module can switch up to 8 amps or 2000W, , which is more than a standard UK lighting circuit of 6 amps.

maybe extending the neutral cable and dragging it down into the light switch might be as feasible as anything else?).

That is the best option, as the device can go behind the light switch and is much easier to access if and when required.
Normally done by installing 3C&E cable to the switch, so you have L, switched L and neutral.
The rest of the circuit wiring is the same as any other lighting circuit.