# Is it possible?

1. May 20, 2006

### .....

Had a bit of a dispute with a friend over the possibility of a circuit and what it could do... I could be wrong, but I don't see how this is possible -

He claims that it's possible to wire a circuit containing three switches and a light, and have it so that any of the three switches can turn the light on OR off, - regardless of the other two switch's positions... for example, two of the switches on and the other off - whichever position a switch was flicked to last will determine whether the light is on or off....

now I can see how you could make a circuit where any of three switches would turn the light on, but all three switches would have to be off for the light to be off.. or alternitavtely all three switches on for the light to be on and any switch would turn it off... but what I described above doesn't seem possible to me without some sort of component/circuitry which registers which switch was flicked last and gives priority to that switch accordingly... (and plus he said that wasn't needed)

so, am I right? and if not please show me how the circuit works, I'd love to know

ta

2. May 20, 2006

### wolram

Have a look at this site (four way switch) .

http://www.1728.com/project2.htm

3. May 20, 2006

### .....

Ahhh I think I see.... my mistake was in assuming the switch had a set "light on" and "light off" position, rather than just needing to change whatever position it's in to change whether the light is on or off.

ta