Andy Wade wrote:
On 24/03/2011 23:22, Ronald Raygun wrote:
However, there is a solution involving two double pole changeover
switches.

Surely you can do it with two single-pole changeover (SPDT) switches.
Using your terminal naming, so SW1 has 'fixed' contacts A1 & A2 and
common or moving contact A (and SW2 similarly has B1, B2 and B). Now
connect

- A1 and B1 to -ve supply
- A2 and B2 to +ve supply
- A and B to the outgoing wires X and Y.

If both switches are 'up' or 'down' X & Y are connected to the same
supply pole, so both lights are off. If one is up and the other down
there will be an output to X & Y, with the polarity dependent on which
switch is up.


I was going the make Ronald work it out for himself as he likes a challenge.

--
Adam