No such thing as "IT CANT BE DONE". Dimmer not working as requires in my lighting controls :(

[Thomas Thornburn]

Hi everyone, I've come here in frustration and would be so very grateful to who ever can help me..

The lighting controls are required to: Dim hallway lighting (9 x GU10 LED) after 10pm untill 6am to 50%. The rest of the time NO dimming is required.

To complicate this, these lights are switched with a PIR (there is also a single 2way switch that is used to allow for permanent override)

The current setup: I am using a time clock to operate a double-throw relay to switch a dimmer into the circuit. So before 10pm, the PIR switches as normal through the N/C of the relay. After 10pm, the PIR switches through the N/O of the relay, energising the dimmer switch...

HOWEVER! I did not foresee that the dimmer switch would reset when de-energised and require physically turning on making the whole thing useless!

I have rang round several technical support persons and not getting anywhere, so I'm asking if anyone knows of a dimmer product that can stay energised or stay locked in its mechanically set position??

Obviously, ANY viable solution would be awesome!

BUT as you might realise, this setup is a way of not spending too silly money on various smart products or more commercial setup solutions, and a way of using the PIR's already in place.

Many thanks in advance.

 

[Thomas Thornburn]

Just to add, any solution is a solution, no matter how unorthodox.. I've been pondering with ideas such as having a very small separate load on the dimmer, just to keep it energised, then using another double-throw relay to rapidly swap that load for the intended hallway lights with in intention of it being quick enough to not reset the dimmer :/ ???

 

[sparkdog]

Might be able to use a two channel central heating timer.

 

[littlespark]

2 way dimmer? Supply it on one of the strappers, switchwire in Common
They are designed that they can be switched from another position and should be at the required dimming level when turned on, and not reset.
It can be frustrating trying to dim LED's at the best of times, so you should be certain your LED's can be dimmed in the first place.

 

[SparkyChick]

Personally, I'd try a Varilight vPro rotary dimmer. They are push on/off and they don't reset the brightness when powered off as they use a traditional potentiometer.

 

[Marvo]

Any suitable rotary 2-wire dimmer with a standard timer should work. The PIR supplies the entire circuit with the dimme and the timer literally just short circuits the dimmer during daylight hours.

 

[Thomas Thornburn]

Thanks for the reply's all

Probably more questions made at this time with a few in me..

I'm trying to figure how the central heating time could help? If you could elaborate a little more.

The 2 way dimmer sound interesting but that's also giving me a headache right now :/ I feel like I'd have the same problem, just over two switches i.e it would still need to be physically turned on manually at either switch..?

ah one of the technical support guys at varilight said the Vpro MIGHT work, tempted to get one and see, just be annoying to be stuck with an unneeded dimmer.

 

[Marvo]

 

[Richard Burns]

If you had a PIR with volt free contacts or used the PIR to switch a relay then the PIR could just connect the light to the supply.

Meanwhile the supply could alternate between dimmed or non dimmed supply by the timer operating a SPDT relay between input and output of the dimmer.
Very similar to Marvo's solution, just slightly too complex.
(I have now had to try and make my diagram neater!)

 

[Marvo]

There's loads of ways to skin this cat, the logistics depend on the layout of your particular installation and the native switching available from the timer and the PIR will determine whether or not you need relays as shown in Richards drawing.

 

[simpson93]

Hi Thomas,
Would it be possible to use a leading edge dimmer that instead Of what I presume is a trailing edge dimmer v pro?

 

[marconi]

Further to Sparkychicks #5:

We have a Varilight dimmer controlling 8 LED lamps in our conservatory:

I think it is this one - it looks exactly the same:

1 Gang 2 way V-COM LED Dimmer Switch 1 x 100w - White - https://www.tlc-direct.co.uk/Products/VLKQP101W.html

(I don't want to unscrew it because it will crack the new paint around it and my wife will complain.) It does have the soft start feature so I am pretty sure it is this one.

I have set the dimness to about 50% and turned the mcb supplying it on/off 5 times and each time the LEDs illuminate at 50% when power returns.

 

[Pete999]

View attachment 44640

No cpc present at the timer, Dimmer or PIR

 

[Thomas Thornburn]

Morning all! Some of you guys really go above and beyond!

The diagrams where awesome (think that got a little competitive) lol

Big thanks to 'marconi', your a legend for trying that for me! Tbh that sound like my solution right there and the simplest one possible

If that won't cut it, I'll likely go with the diagram from Richard, liked that.

Thanks you all!!