On Nov 3, 1:11*pm, John Rumm wrote:
On 03/11/2011 12:30, tony sayer wrote:

Anyone here know if one of these exists?.

Did you mean to post this to the FiT thread...?



We have a job to do to control some lights, in essence similar to the
PIR operated light in your front garden except that this is Six separate
lights around 2 kW in total load.

The lights are in shall we say, very awkward locations and are a PITA to
get to. It seems to me that if we under run them a bit then their
lifetime before replacement might be extended. There is a fair old bit
of cable run in this too so its prolly going to loose a bit anyway..

What also seems like a good idea is to soft start them i.e. just fade up
the volts applied over a second or so to reduce the switch on surge when
cold.

We have a simple infra red light beam detector arrangement that will
give a contact closure when triggered which we could interpose another
relay to source volts to the larger relay. If that one could accept
either a simple contact close or volts applied say 12 to 24 then fine.

If it can also stay switched on for a time period perhaps a minute or
so then better still.

What about step starting? Fire up the lights in series pairs, and then a
couple of secs later hit them with full volts? Just need a couple of
relays and a simple timer that way.


Tony hasnt mentioned which type of lights they are, it makes a big
difference as to what works and what doesnt.

Switchover from series to parallel working can be done with a relay
driven by rectifier, R,C. But in the case of GLS lamps, it makes close
to zero difference to life expectancy.


NT