Need wiring help

I have switch A and switch B.

I want switch A to open and close the door at all times.

I want switch B to open and close the door only if A is on.


How do I do this? Please help, it's so much harder than I thought ; -; I'd prefer not to rely on a 3rd switch, I know how to do it with 3.

 

Thank you, my bad, it's been a while.

 

The way I read it:

Code:

  A      B       door
on     on      open
on     off     open
off    on      closed
off    off     closed

This does not do what you want, e.g. the state of switch B is ignored completely since

Code:

"(A and not(B)) or (A and B)"

simplifies to "A".

You could solve this using a bunch of not gates and latches, but just using another small wall switch is a lot easier.

 

I would not even remotely claim this is a good solution, as I'm pretty new at this and even to me it looks clunky but it does what you said.





Also note that this design requires the switches (or at least Switch B ) to be the kind that has an input.

So at its core, it's just two switches linked to a door by an AND gate. What all that extra stuff accomplishes, is that when you flip A to ON, B is forced to ON as well, if it wasn't already. The delay allows it to distinguish when you have just switched A on, from A just being on. In the latter case B will work as normal.