Need some Relay advice .. Please help !!

[DWTK]

Hi All

Im trying to build this lighting circuit for a light feature I built. Diagram attached. Let me give a quick explanation I have a 240v supply feeding a dimmer that controls the main lights of 600W in the feature. I have represented it in the diagram as one bulb. Attached to this feature I have a second LED circuit with an LED driver that is in turn is connected to led dimmer and led strip. What I would like to happen is when the mains dimmer is switched on ( even at lowest setting ) I would like the second led circuit to come on and then when the dimmer is switched off the LED circuit to turn off with the main lights. my electronics knowledge is limited and I understand I need a relay to switch the LED circuit on when the mains dimmer is switched on and then off again when the mains dimmer is switched off. .Can you guys give me any advice on is what type of relay can be used to do this and if my circuit is sound .

 

[Minder]

If this is a TRIAC style dimmer with a linear pot for manual control, why not put a switched pot in and use the switch to control the LED circuit similar to standard light dimmers, if already used, then you may find a DP version or use the present switched portion to control a relay. .
If this an automatic function then it would require a re-think.
If a relay is required any small 240v version should work, is the present 600w fed from 240v DC?
M.

 

[DWTK]

Your correct I do want the coming on and off of the 600w bulbs and the led driver to come on at the same time . But I don't want the 600w dimmer to create any resistance to the led circuit . I think I understand what you are getting at . I am a noob to circuits. In essence I need a relay that will switch the led circuit on when any current is detected and turn off when no current is detected . If that makes sense . Would a latching relay work . If so what type . If you can point me to a eBay link I would be much appreciated .

 

[Minder]

It would be an advantage to know exact details of the items you have right now?
What turns the 600w dimmer on/off?
Manual switch, switch on a pot, relay etc?
M.

 

[DWTK]

The wall dimmer Is a switch and dimmer in one .

http://pages.ebay.com/link/?nav=item.view&alt=web&id=251655906936&globalID=EBAY-GB

The led driver is 60 w

http://pages.ebay.com/link/?nav=item.view&alt=web&id=390556572105&globalID=EBAY-GB

I haven't bought the led dimmer yet but it will be a cheap manual dimmer . Set to a certain level . Which it will stay at. The leds only need to come and off to a certain level .

 

[morphingstar]

<<when the mains dimmer is switched on ( even at lowest setting ) I would like the second led circuit to come on and then when the dimmer is switched off the LED circuit to turn off with the main lights.>> This I see as 2 circuits in parallel controlled by 1 switch. The switch has no controlling influence on dimmer settings.
The diagram looks different though.May be you can draw a block diagram and explain the intended interrelation between the 2 circuits in a new approach.

 

[Minder]

You show the supply as DC I take it is 240vac? Otherwise a Triac dimmer would not work.
M.

 

[DWTK]

Yes the mains supply is 240v AC . from the LED Driver to the Led strip its 12v DC. apologies if the diagram is confusing. My electrical drawing skills are limited. I will try do a block diagram to make the picture more clear.

 

[DWTK]

Ok I split out the circuits to make it simpler . The wall dimmer is a switch and dimmer in one. See link .

http://pages.ebay.com/link/?nav=item.view&alt=web&id=251655906936&globalID=EBAY-GB

What I would like to happen is when the wall dimmer switch is turned on in circuit 2, the completed circuit 2 with activate relay in circuit 1. This will complete the circuit 1. When the wall dimmer switch is powered off in circuit 2 . Then circuit 1 will deactivate as the relay switching leg 3 loses power. See diagram attached.

 

[DWTK]

I might have possible solution. To Trigger the relay in circuit 1 could use a optocoupler . But the Optocoupler relays I could find have a DC input which means I will have to convert my 240 VAC to 5VDC .

http://www.ebay.co.uk/itm/New-5V-1-...261?pt=LH_DefaultDomain_3&hash=item20ea2f7d35

does anyone know the resistor diode combination to get from 240VAC to 5VDC.

 

[DWTK]

What about an ssr ac to ac like this

http://pages.ebay.com/link/?nav=item.view&alt=web&id=251809782929&globalID=EBAY-GB

 

[Minder]

I still don't know why you can't come off/tap into the same switch as the dimmer?
It usually has a S.P.S.T. switch on the back of the pot to turn off the 240v to the triac circuit.
And switch into whatever device/transformer/supply you have feeding the low voltage unit??
M.

 

[DWTK]

It's to do with location . My walls are solid brick and the wall dimmer switch is already wired to the ceiling rose . Hence circuit 2 will turn on and dim with that . Circuit 1 is powered by tapping the lighting ring so I can get a constant 240 v . If I wire the led driver to the dimmerable ceiling rose the voltage would fluctuate for the led driver . That's what I have kept the circuits separate . What Iam looking for is a mechanism to turn on circuit 1 when circuit 2 is turned on and set to what ever resistance on the dimmer . Using an ssr with optocoupler is what I have come too . Do you have any other ideas .

 

[morphingstar]

Pull another wire through the tube connected to 240ac. you need access to original 240 vac to feed the LED cct. Wall switch dimmer input becomes 2nd output for LED. Hence output 1 from wall dimmer to the dimming load, output 2 (240) to LED power supply.
Pull in another wire: Use the switched wire to pull in 2 new wires from wall switch / dimmer to load.
Then reconnect as before and use the second wire to feed the LED p/s.
In worst case you need a second wall switch where the dimmer is, that is if there is no other way to turn off LED p/s, e.g. it load switch is part of the slider.
This is not an electronic solution. It might work, if conditions allow it.