At my workplace there's a room with two entrances, each featuring a push button light switch, A and B. There are two ceiling mounted lights, 1 and 2.
Switch A switches both lights on/off. Funny enough, if both lights are on, switch B switches off a single light (2). Now in this state, switch A "flips" the state of the two lights (2 goes on, 1 goes off).
| SW-A | SW-B || LAMP1 | LAMP2 |
+------+------++-------+-------+
| on | on || on | on |
| off | on || off | off |
| on | off || on | off |
| off | off || off | on |
+------+------++-------+-------+
I don't know if these are 3-way or 4-way switches.
Just out of academic curiosity: how exactly is this – obviously flawed – circuit possibly implemented?
(Disclaimer: I'm a physician, not any kind of engineer)
Best Answer
Rewriting your truth table a little more succinctly:
simulate this circuit – Schematic created using CircuitLab
Figure 1. Mis-wired two-way switching circuit.
Does this fit?
In Europe this is referred to as a two-way switching circuit. In the US the switches are referred to as 3-way as they have three wires.
It looks like LAMP1 is wired to the wrong terminal on the switch.