Need help with wiring!!

[Iestyn Rhys Pritchard]

Completely unrelated to caving, but I know a couple of people on here know a thing or two about electrics!

Right, 12V DC. I have 3 sets of lights with individual switches. How do I wire a 4th switch that would turn on all the lights together without turning each individual switch on?

The way I had it wired was fine, with each switch turning on the correct lights, but since adding the master, every switch turns ALL the lights on.

I can understand why this is happening, but is there a way around it? I wondered if adding diodes would solve the problem?

[Danny Sutton]

The easiest way is with a relay.

one with a single coil operating 3 switchs (3 separate circuits)

should be easy enough to get hold of from a maplins

you could easily do it with 3 simple single circuit relays, like the type you would use when fitting spot lamps or something like that,  but it means more wire and more connections.

i may have a 3 circuit one knocking about, I'll have a look, but there is a good chance the coil will be 24v.

[Iestyn Rhys Pritchard]

Thanks pal!

I'll have to pop in to the maplins in llandudno on the way to the party tomorrow!

[Danny Sutton]

this would be how to wire it with 3 single automotive relays, the type you use for spot lights or what not

[Danny Sutton]

humm the forum resizes pictures.. i can send it you on facebook if you need it.

[Iestyn Rhys Pritchard]

That's great thanks!!

i take it this is an extra circuit on top of what I've already got and i just piggy back the ? from the relay and the ? from the individual switch?

[Danny Sutton]

This is an extra circuit yes.

how you connect it to your existing circuit is up to you, without seeing how it is currently wired i couldn't guess how you would do it.

if you added this with loads of wire to each item and the battery, it wouldn't interfere with the existing wiring.

if you want the master switch to HAVE to be on to turn the other items on individually, your existing switches need to be in the wire between pin 87 on the relays and the item you want it to switch on.

but that would mean each switch would have to be turned on for the master switch to turn all 3 on at the same time.

if that makes sense.

[Iestyn Rhys Pritchard]

Perfect sense. Thanks again

[Andrew Farrow]

did you get this sorted - dans " solution " seems like a fooking hideous mess

a single 3PDT relay - would create a single master switch

[Iestyn Rhys Pritchard]

Nah, i haven't got round to wiring it yet. Dan did suggest a 3PDT relay, but i wouldn't have a fooking clue how to wire it

[Les Williams]

Does this make sense?
On the left, how it is now, on the right with a 3PDT relay.

[Danny Sutton]

[quote="Andrew Farrow" post=21367]did you get this sorted - dans " solution " seems like a fooking hideous mess

a single 3PDT relay - would create a single master switch[/quote]

I had already said that 3 weeks ago.

[Iestyn Rhys Pritchard]

[quote="LesW" post=21378]Does this make sense?
On the left, how it is now, on the right with a 3PDT relay.[/quote]

Yeah, that looks about right. I don't suppose you know what the numbers on the relay are? Or will there be some sort of info sheet when i get the relay?