Workshop power supply with multiple options and monitoring of voltage and current using a PIC microcontroller plus LCD readout.

The dual power supply unit (PSU) described here can be built in several forms. At the simplest level it can be built with a single d.c. output switched for 5V or variable between about 6V and 9V. This shortened version is probably an ideal starter power supply for those who have been following the recent Teach-In 2000 series and now wish to start adding workshop equipment. This version will be described in Part 2, as will other constructional options. Some aspects of the main PSU have also been described in such a way as to reinforce the understanding of power supplies by Teach-In 2000 readers.

The full version of the dual power sup-ply provides PIC microcontroller monitoring of voltage and current, displaying the data on a liquid crystal display (l.c.d.).