Time Lag Switch

[securespark]

Thanks. Changing the arrangement inside the room is a no-no.

Please read my previous post. I edited it a few mins ago.

 

[JohnW2]

Thanks, everyone. MiL is adamant there should be a switch out there with her name on it. ... Maybe I can get away with omitting clause 3. ... So, a timer switch that illuminates when on?

Yes, if you can find one - although, if a neutral is available, it would probably not be too difficult to add a neon/LED to one which didn't have one, provided there was a neutral available (and you didn't want to be 'naughty' ).

As for "Clause 3" (ability to switch light/fan off before end of timed period), it occurs to me that many/most/all electronic time-lag switches probably behave as I described (revert to 'off state' if one momentarily interrupts the supply). If that's the case then you could probably achieve that 'off' function by preceding almost any electronic time-lag switch with a momentary-action N/C (push to break) push switch - and you might even be clever enough to add even that (as well as an LED/neon) to the timer switch's faceplate!

Kind Regards, John

 

[333rocky333]

seem to recall these change colour Blue to Red, or maybe the light goes off when the main lights on and you can early off by pressing them.
2 wire and 3 wire available.

https://elkay.co.uk/product/350a-1-illuminated-push-button-timer/

 

[JohnW2]

seem to recall these change colour Blue to Red, or maybe the light goes off when the main lights on and you can early off by pressing them. ... 2 wire and 3 wire available. ... https://elkay.co.uk/product/350a-1-illuminated-push-button-timer/

Yep, almost right - it seems that the blue 'locator' ring doesn't change colour, but the small red LED adjacent to the ring lights up when the load is powered. Also, as you say, the 'off' function is also there. So, all your boxes ticked, it seems (at a price!!). Instructions can be found at (click here) , and that includes ...

Kind Regards, John

 

[securespark]

seem to recall these change colour Blue to Red, or maybe the light goes off when the main lights on and you can early off by pressing them.
2 wire and 3 wire available.

https://elkay.co.uk/product/350a-1-illuminated-push-button-timer/

Is that the same as the one I found at RS....on the previous page.....this one?

https://uk.rs-online.com/web/p/light-switches/7191888

Edit: no.

 

[JohnW2]

Is that the same as the one I found at RS....on the previous page.....this one? https://uk.rs-online.com/web/p/light-switches/7191888 Edit: no.

As you say, no You're one is "RS Pro" branded, not Elkay.

One thing which is similar is the (high) price

Kind Regards, John

 

[securespark]

I knew it wouldn't be cheap!

Often, you find that "own brands" are a brand name product under a different name and in a different box.

I remember once buying Supalec (or something similar) waterproof sockets and when they were delivered, they were MK, but much cheaper!

 

[JohnW2]

I knew it wouldn't be cheap! Often, you find that "own brands" are a brand name product under a different name and in a different box.

Indeed - but, as you go on to imply, one normally expects the "own brand" versio to be appreciably cheaper than the branded product, not the same (high) price!

Kind Regards, John

 

[SUNRAY]

When I came to draw it, I realised that if one wanted to have the indicator (neon or whatever) one would need 4C (+E, to be regs-compliant!) cable to the switch box.

However, I then realised that if one put an electronic timer module (maybe even one stolen from, or intended for, a timer fan!) in the switch box, one would only need 2-core (+E !) cable to/from the switch box, and wouldn't need a time fan - something like the below, although I'm sure you would prefer a simpler, essentially off-the-shelf, solution (and no 're-wiring') ....

View attachment 263910

Kind Regards, John

Easier?

 

[JohnW2]

Easier? ....

Hmmmm. 'Arrangement'-wise the only difference I can see is that I had everything (both switches, timer module and LED) in one 'enclosure' (backbox at existing switch location),whereas you have two.

However, maybe because it's the middle of the night, electrically speaking I really cannot make any sense of what you are proposing. Could you perhaps offer some explanation/clarification?

Kind Regards, John

 

[SUNRAY]

Hmmmm. 'Arrangement'-wise the only difference I can see is that I had everything (both switches, timer module and LED) in one 'enclosure' (backbox at existing switch location),whereas you have two.

However, maybe because it's the middle of the night, electrically speaking I really cannot make any sense of what you are proposing. Could you perhaps offer some explanation/clarification?

Kind Regards, John

the big benefit is not having to change existing T&E to switch, that assumes it's loop-in at the light
Does this help?

 

[JohnW2]

the big benefit is not having to change existing T&E to switch, that assumes it's loop-in at the light

Yes, I worked out that much, but ...

Does this help?

Not a lot, I'm afraid, even after a night's sleep Starting with this ....

.... (a) is that the existing (i.e. 'an ordinary') light switch, or are you proposing changing it to a momentary-action push switch? and (b) whilst I'm not quite sure what you mean by a "series LED module", depending on how much quiescent current the timer modukle daws, I imagine that the LED might be dimly lit even when the light/fan were off? Anyway, my greatest difficulty is really with ...

firstly, is that 'switch' an actual switch, or does it represent the 'switching function' (relay or triac) of the timer module? I can but presume the latter (particularly given that you say in may be located 'in existing light').

Whatever, I can but presume that you are suggesting that the trigger input of the timer module be connected to the permanent L (you show no separate 'trigger' input) - is that your idea? If that were the case then, as far as I can see, whenever the switch (in the enclosure with LED) were closed the lights/fan would be permanently on, regardless of the timer.

Maybe I'm just being dim, but I think you probably need to explain to me (in words) the functionality of your circuit as you see it. Thanks.

Kind Regards, John

 

[SUNRAY]

This very simple circuit

is a grid plate using a 1 way switch and a LED module which is designed to work with 3 volts across it (the annoying thing is I haven't been able to find them listed on line but have purchased from wholesalers). This is followed by the timer module and lamp and (not shown) fan.

One of the spec's is for a 'neon' to be lit if the switch is on, so yes I hope it will be lit by the current of the timer.

The timer module

such as page 3 of: https://assets.omron.eu/downloads/d...3y-series_solid-state_timers_datasheet_en.pdf

Contains the timing electronics and a relay.

Operation:
Move switch to 'on', that starts the timer which closes it's relay contact, that also illuminates the LED module. Lamp lights via switch, LED module and timer contact.

Following that, either:
1) Move switch to 'off', that removes all power to timer and lamp. Lamp is extinguished as is LED module. OR
2) Timer times out. That extinguishes the lamp but leaves the minor current of the timer to illuminate the LED module until the switch is moved to 'off'.

I believe that satisfies my interpretation of specification, other than the possibility the timer module 'timed out' current being possibly higher than just the requested 'neon'.

 

[JohnW2]

This very simple circuit is a grid plate using a 1 way switch and a LED module which is designed to work with 3 volts across it (the annoying thing is I haven't been able to find them listed on line but have purchased from wholesalers).

As I said, I'm not familiar with "series LED modules" and, from what you say, it sounds as if it might not be easy to find one!

One of the spec's is for a 'neon' to be lit if the switch is on, so yes I hope it will be lit by the current of the timer.

That's not how I read it. I read the requirement to be that the LED be lit when the light/fan (not the switch) was 'on'- in other words it would be required that the LED went out at the end of the timing period -which, as we've both said, may not be the case if the quiescent current of the timer module were enough to light the LED.

The timer module [such as page 3 of: https://assets.omron.eu/downloads/d...3y-series_solid-state_timers_datasheet_en.pdf ]Contains the timing electronics and a relay.

OK, but you've move the goalposts in terms of what I was talking about - which was a timer module as per that found in a 'timer fan'. Anyway, given what you are now talking about ...

Operation: Move switch to 'on', that starts the timer which closes it's relay contact, that also illuminates the LED module. Lamp lights via switch, LED module and timer contact.

OK

Following that, either: 1) Move switch to 'off', that removes all power to timer and lamp. Lamp is extinguished as is LED module.

Agreed.

... OR ... 2) Timer times out. That extinguishes the lamp but leaves the minor current of the timer to illuminate the LED module until the switch is moved to 'off'. I believe that satisfies my interpretation of specification, other than the possibility the timer module 'timed out' current being possibly higher than just the requested 'neon'.

As above, my interpretation of the requirements was that the LED should go off if the lights/fan go off due to the timer period having ended (with switch still on)

It also means (which might confuse secure's MIL) that if the light/fan go off because of the time (with the switch still 'on'), she would have to turn the switch 'off', and then back 'on' again to get the light/fan to come on.

Kind Regards, John

 

[JohnW2]

...It also means (which might confuse secure's MIL) that if the light/fan go off because of the time (with the switch still 'on'), she would have to turn the switch 'off', and then back 'on' again to get the light/fan to come on.

It has occurred to me that it may well even slightly confuse you, I or secure, let alone his MIL, since what one would have to do 'to switch the light on' would vary slightly according to what had last caused the light to go off (manual switching or timer).

Kind Regards, John