Digital output with sink/source driver

When it comes to using a PC or a microprocessor system to control ‘real-world’ loads like lamps, relays, and motors, there are basically two camps: programmers and hardware specialists. The combined species seems to be rare! Anyway, this article is aimed at the latter group. The circuit diagram shows a one-channel power driver with an (optional) electrically isolated input and a power output capable of sinking as well as sourcing current.