outside lighting and dusk sensor

[TrueBlue]

I have some outside lighting which I have wired to a timer and a photocell. This means that they come on when it goes dark (without me having to continually adjust the timer throughout the year!) and go off at midnight.

What I would like are more efficient and longer lasting bulbs. I have tried the low energy type but I get 'flicker' as they come on (I now know that I should not be using them with a photocell).

• Is there another type of bulb that will work with a photocell that is energy efficient? (sodium?)

• Is there a more sophisticated photocell that I can use with low energy bulbs?

• Any other suggestions?

[Rusty]

Had a similar problem with halogen lamps burning the photocell unit out. You could try adding a relay eg

are cheap as chips and will carry up to 13A and any sort of load, but the back emf from the coil will need suppression or it might also damage the photocell thyristor.

rusty

[TrueBlue]

Thanks for the reply. Where would I connect a relay into the circuit and which type would I need?

[Andrew Gabriel]

Or use a photocell with built in relay and a neutral connection, such as:

(Part number SRPCM1000/70L if the URL doesn't work without my cookies) which I fitted into the top of an outdoor lantern some ~5 years ago, and has been switching compact fluorescents ever since.

[Rusty]

Can't improve on this. Relays are commonly found in cookers with electronic timers (which is where mine came from) but the 1200W photocell would be a better bet (though it doesn't actually specify it has a relay)

rusty .

[Andrew Gabriel]

It does have -- the 3 wires is a good clue, but if you are standing near it, you can hear the relay click. Interestingly, the spec seems to have changed slightly since I bought mine, which is rated 500W ballast, or

2000W tungsten, but it's the same part number.

There are other formats, e.g. with the photocell detector remote from the small electronics box, for situations where that fits better into the luminare.

[Rob Morley]

You want one that runs off 240V AC and will handle the power of the lights that you'll run off it (which in this case is presumably pretty low). 10A DPDT Miniature Relays...Min 10A DPDT 240Vac with spade connectors would probably be the most convenient package.

[chris French]

In message , TrueBlue writes

I have a photocell switching an outside light with a CFL it works fine.

The photocell unit said it was suitable for this application the on the packaging. Forget the brand, but it came from one of the sheds

[romic]

I've lost the original post/comments to this thread, so I've tagged my comment on to this one.

Any timer that uses a relay to switch on and off is fine with any sort of lighting. Many of the timers designed just for lighting use a triac instead of the relay - sometimes called solid state switching. This is what gives the problem with energy saving bulbs and there is also usually a requirement for a minimum wattage.

If getting an all-in unit, then see if it states on the package how it is switched (e.g. by relay or triac). If it doesn't state this, one way is to look at the maximum wattage that can be switched. Usually a triac will only switch low wattages (up to around 500w) unless fitted with a decent heatsink. If the unit states a maximum wattage of 2-3Kw, then it's almost certain that it uses a relay.

If using a separate photocell, then just get an ordinary timer and connect it to that.

Roger (my reader sometimes loses mail/newsgroup messages

- if you think you should have had a reply/comment, please e-mail me again. Ta!)

[TrueBlue]

Thank you to everyone who replied.

Now I know what I need, I have searched the internet and come up with what looks like the perfect solution. It is a Steinel Nightmatic 3000 from

for £16. It also has a night economy mode, so that you do not need an additional timer.