LED Light switch timer

[jamesdean1986]

We have a few lights all with LED bulbs on the front of our house but always forget to turn then off when we go to bed so I thought I get a light switch timer but all of them say not suitable for LEDs. I don't understand why they wouldn't work.
Does anyone know why?
There is only one I've found that does but it's basically a battery operated rocker that it's quite bulky and ugly.
Any other suggestions?

 

[Echo the husky]

I expect the timers you have been looking at are 2 wire and use the load when they are off to complete the circuit and charge the timers electronics. This causes LED lamps to either flash or light dimly when they are off. You need to find a 3 wire timer that requires a neutral to work. You can buy both indoor and outdoor versions.

 

[jamesdean1986]

Thanks Freddo. Given today's technology I wouldn't of thought a timer that worked with LEDs was too much to ask for.

 

[Iggifer]

Well Danlers make Time Lag switches that work with LED's, but with those, you set the interval between 1-120 minutes, and then when it goes off, you have to get up to press it again.

You could also leave the existing switch as is and fit a microwave sensor next to the light. That way, the switch will work as normal (because microwave sensors are MUCH better than PIRs) and if you leave the room with the light on, the microwave sensor will cut out after x amount of time.

I would check with manufacturers of M/Sensors before buying one, because some PIRs, at least, can behave a little strangely if you switch off their live feed. (I've seen a few that when you turn the switch on, will close and light the light, but then go off again, after their preset time, regardless of whether or not there is motion - this may not be the case with M/S though - like I say, they're much better)

 

[JohnW2]

Thanks Freddo. Given today's technology I wouldn't of thought a timer that worked with LEDs was too much to ask for.

It's not - provided that, as freddo said, you use a timer which is appropriate for an LED load.

Kind Regards, John

 

[jamesdean1986]

Thanks Freddo. Given today's technology I wouldn't of thought a timer that worked with LEDs was too much to ask for.

It's not - provided that, as freddo said, you use a timer which is appropriate for an LED load.

Kind Regards, John

Any suggestions as to where I can find one because so far I haven't been able to?

 

[AndyPRK]

Well firstly you would need to check if there is a neutral at the switch.

Usually found if there are black or blue cables joined in the back box.

If sure there are better options. Eg

1 dusk till dawn sensor
2 neon inside
3 ignore as LEDs are cheap to run

 

[Echo the husky]

CP Electronics have a good range. If your existing wiring has no neutral at the switch you may be able to use one of their remote timer units to save massive wiring alterations.

 

[ban-all-sheds]

We have a few lights all with LED bulbs on the front of our house

What are they for?

Clearly not for you, as you're indoors.

Are they so that the neighbours can tell when you've gone to bed? Is there a sign which visitors wouldn't be able to read telling them not to ring the bell if the lights are off?

 

[ericmark]

We have a few lights all with LED bulbs on the front of our house

What are they for?

Clearly not for you, as you're indoors.

Are they so that the neighbours can tell when you've gone to bed? Is there a sign which visitors wouldn't be able to read telling them not to ring the bell if the lights are off?

Now that's a good idea, my father-in-law is for ever letting him self in when we don't really want visitors two lights visitors welcome or go away we are busy sleeping would be great even if not written on the lamps.

 

[JohnW2]

Now that's a good idea, my father-in-law is for ever letting him self in when we don't really want visitors two lights visitors welcome or go away we are busy sleeping would be great even if not written on the lamps.

My headmaster had a set of 'traffic lights' on the door of his office/study - "Come in", "Wait" and "Go Away"

Kind Regards, John

 

[ericmark]

I have been pestered by my wife to have a light in the front of our house. She in fact bought a 120W flood light from Aldi with a sensor which will switch it on at night when there is movement with three variable controls light level, movement sensitivity, and time it stays one for. I hate the thing but still had to but it up, however it's only plugged in so easy to get rid of it.

However inside the junction box you have assess to 4 terminals earth, neutral, permanent line and switched line so it would be easy to daisy chain it to other lamps. The bulb lasted 3 days, the replacement is a 5W LED which worked fine so there would not be a problem connecting other lamps to the same sensor.

OK only day two with the new bulb so don't know how long it will last, but the idea of running other lamps from same sensor does make some sense.

As to timers the simple plug in timer

is cheap at around £5 and since mechanical can't see any problem with LED lamps.

Most central heating units have some sort of timer again relay contacts so unlikely to be a problem with LED lamps. I did quick internet search and there are 100's of timers all which are 3 wire so would work. The only problem is where you want a two wire timer, in that case some power must go through the lamps and the type of lamp is as important as the type of timer. I would expect any lamp which states it is dimmable will work, point is lamp dimmers need to have some current to work so will not start flashing as a capacitor inside the lamp charges.

Two wire time switches don't tend to quote how much current will flow when off. I looked at the "Elkay 2 Wire Master Push Button White" and it states "When used with some low wattage lighting, heating and ventilation circuits please ensure a capacitor of 2 microfarads (minimum) is fitted. Supplies of suitable Elkay capacitors can be found at your stockist (Ref PFCC-1)" I would guess many others have similar instructions.

Seems they are called "Power factor correction capacitors" and cost about £5 which does seem rather high for what they are. The name ensure they are suitable for long term use and at 50Hz they will clearly allow some current to flow which is enough to run the switch electronics.

 

[stillp]

My headmaster had a set of 'traffic lights' on the door of his office/study - "Come in", "Wait" and "Go Away"

Kind Regards, John

So did the head of electrical engineering at the college where I worked. Was your head an officious little tw@ as well?

 

[JohnW2]

My headmaster had a set of 'traffic lights' on the door of his office/study - "Come in", "Wait" and "Go Away"

So did the head of electrical engineering at the college where I worked. Was your head an officious little tw@ as well?

Sort-of. He was an ageing archetypal Victorian (with a PhD in Classics!), who was convinced that he was running an upmarket "Public School" (like Harrow School, which was only a stone's throw away) rather than the state (boys) Grammar School which it actually was.

He had very little interest in any pupils/students who did not have the potential not merely to 'get to' Oxford or Cambridge, but to get scholarships thereto, and could well have ended up in very deep water (if not prison!) today for some of the things he said. Most of us were expected to 'fast-track' to doing O-Levels in the 4th form, and then jumping straight into the 6th form. Only those were not 'up to that' went into the 5th form, and he openly and regularly referred to them not as "the 5th form" but, rather, as "the scum of the earth". Any remotely 'pointed' shoes (fashionable at the time!) he described as "abominations worn only by third-class Swedish tourists", and our sister Girls' school around the corner as "a den of temptation"! He tried to move heaven and earth (but eventually failed) to 'ban' girls from our school dances and dramatic productions, and what was in reality the school's "Jazz Club" had to be called the "Afro-American Music Appreciation Society" before he would allow it to exist. Happy times

Kind Regards, John

 

[JohnW2]

... "When used with some low wattage lighting, heating and ventilation circuits please ensure a capacitor of 2 microfarads (minimum) is fitted.

That sounds quite large. A 2μF capacitor has an impedance of only about 1591Ω at 50Hz, so has the potential to pass a current (if straight across the supply) of ~145 mA at 230V.

Kind Regards, John