This bracket was designed to mount a small digital voltmeter on the back of my Powertech MP3800 laboratory power supply. While the power supply does in fact have an analogue voltmeter on the front, I prefer something more precise, with known accuracy.

http://teslaandi.wordpress.com/2014/02/02/power-supply-voltmeter-retrofit/

• Purchase one digital voltmeter, as shown in the images (commonly on eBay, referred to as "0.36" LED Display Car Digital Voltmeter"). Ensure that the voltmeter's operating and measurement voltage ratings match the range across which you will be using the power supply.
• Print one set of brackets as included in the STL file.
• Assemble as shown.
• Can be screwed onto the GND and +ve power terminals on the back of the power supply.
• Connect the black wire to the ground terminal. Connect the red and blue wires to the +ve terminal.