Laboratory Power Supply
This is a useful power supply based on an ebay kit for the power supply circuit, and a custom made current/voltage meter + controller circuit. The design and build process is fully explained in an instructables article.
The output voltage is ~ 24V and the maximum current 3A, although the current regulation has a little bit of ripple, the power supply is sturdy and good for general purpose usage. Also, the meter circuit is relatively precise: 10mV/1mA.
The display shows the voltage and current as a number and also as a progress bar relative to the OV or OC setup.
The meter and controller circuit has a relay and is able to break the output circuit automatically under Over Voltage or Over Current conditions.