Electronics 2000

Hi

I have to design a circuit that will translate a line (which is pulled up to 14v via a 1k resistor and is either left floating or grounded by the remote circuit), into a 5v or 0v input to a pic.

Can I use for example a BC547 npn transistor and does it matter that the Vbe will be up to 14v?

Thanks

A BC547 from Fairchild allows a collector voltage of up to 50V, but a base-emitter voltage of only 5V. So, no, you cannot use it "IF" you are putting 14V on the base with the emitter grounded. It would help to have at least a partial schematic of your planned circuit. In most cases a resitive voltage divider to the base is appropriate, but there is not enough information to help.

-fab