Relay To Prevent Loop?

[sparkiemike]

That's not what you said.

Two switches then.

The OP has not given details on the application, but I don't think they are wall switches in the traditional sense; see his comment "Basically I have two lives which are switched digitally"

 

[EFLImpudence]

Yes, that may be so.

However the requirements seem to be changing.

Switch A - Gives Live to Appliance A
Switch B - Gives Live to Appliance A and B

The problem is that when Switch A is used, Live gets to Appliance B through its connection with Application A on Switch B.

I have no control over the switches so they can't be changed, I just have two feeds coming from them to make this work.

Unless Appliance B is dependent on Appliance A being on first and as well I do not see the need for your desired arrangement.

It is dependant, consider Appliance B as a booster for Appliance A - there would be times when you wouldn't need Application B.

It would be, except they are both independently controlled - either one of two lives will be live, never both.

 

[washcroft]

I am referring to the two lives being independently controlled, not the appliances. Only one of the two lives will ever be energised at any one time, never both.

...this is why the simple solution of Switch A providing Switch B is a non starter.

 

[EFLImpudence]

I think you will have to give a better and more detailed description of what happens now and what you want to change.

 

[washcroft]

I think you will have to give a better and more detailed description of what happens now and what you want to change.

It's OK now, the people above got it and provided me with the solution I needed. Thanks anyway.

 

[EFLImpudence]

Oh that's alright then.

I must have missed something.

 

[washcroft]

Oh that's alright then.

I must have missed something.

Easily done, it was a tricky one to explain!