We're designing a board that needs to interface with a variety of different furnace control boards, some of which have full-bridge rectifiers and some of which have half-bridge rectifiers. Depending on the design of the furnace control board, our PCB should have a matching rectification circuit to prevent damage to either board (we want to prevent this from happening).
We thought of putting a PTC in the mains line and connecting either the HBR or the FBR. Depending on if the PTC blows, then we'll know if we chose the correct rectification. In the case that the PTC does blow, we would toggle a mechanical jumper (something like this) to short different pins of these 3-pin connectors, selecting the other rectification method.
Is this sane??
UPDATE: We rolled this board to manufacturing and, surprisingly, the setup conducts when two devices are hooked up both with FBR, both with FBR, and with one of each, even though latter should, in theory, cause a short across the FBR and blow its fuse.